Commit Graph

909 Commits

Author SHA1 Message Date
Chen Ridong
ada00d5162 cpuset: separate tmpmasks and cpuset allocation logic
The original alloc_cpumasks() served dual purposes: allocating cpumasks
for both temporary masks (tmpmasks) and cpuset structures. This patch:

1. Decouples these allocation paths for better code clarity
2. Introduces dedicated alloc_tmpmasks() and dup_or_alloc_cpuset()
   functions
3. Maintains symmetric pairing:
   - alloc_tmpmasks() ↔ free_tmpmasks()
   - dup_or_alloc_cpuset() ↔ free_cpuset()

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-25 08:19:57 -10:00
Chen Ridong
5806b3d051 cpuset: decouple tmpmasks and cpumasks freeing in cgroup
Currently, free_cpumasks() can free both tmpmasks and cpumasks of a cpuset
(cs). However, these two operations are not logically coupled. To improve
code clarity:
1. Move cpumask freeing to free_cpuset()
2. Rename free_cpumasks() to free_tmpmasks()

This change enforces the single responsibility principle.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-25 08:19:24 -10:00
Tiffany Yang
8d2a755895 cgroup: Fix 64-bit division in cgroup.stat.local
Fix the following build error for 32-bit systems:
   arm-linux-gnueabi-ld: kernel/cgroup/cgroup.o: in function `cgroup_core_local_stat_show':
>> kernel/cgroup/cgroup.c:3781:(.text+0x28f4): undefined reference to `__aeabi_uldivmod'
   arm-linux-gnueabi-ld: (__aeabi_uldivmod): Unknown destination type (ARM/Thumb) in kernel/cgroup/cgroup.o
>> kernel/cgroup/cgroup.c:3781:(.text+0x28f4): dangerous relocation: unsupported relocation

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202508230604.KyvqOy81-lkp@intel.com/
Signed-off-by: Tiffany Yang <ynaffit@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-25 08:16:55 -10:00
Andy Shevchenko
a214365140 rculist: move list_for_each_rcu() to where it belongs
The list_for_each_rcu() relies on the rcu_dereference() API which is not
provided by the list.h. At the same time list.h is a low-level basic header
that must not have dependencies like RCU, besides the fact of the potential
circular dependencies in some cases. With all that said, move RCU related
API to the rculist.h where it belongs.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Reviewed-by: "Paul E. McKenney" <paulmck@kernel.org>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.upadhyay@kernel.org>
Signed-off-by: "Paul E. McKenney" <paulmck@kernel.org>
2025-08-25 10:13:26 -07:00
Tiffany Yang
afa3701c0e cgroup: cgroup.stat.local time accounting
There isn't yet a clear way to identify a set of "lost" time that
everyone (or at least a wider group of users) cares about. However,
users can perform some delay accounting by iterating over components of
interest. This patch allows cgroup v2 freezing time to be one of those
components.

Track the cumulative time that each v2 cgroup spends freezing and expose
it to userland via a new local stat file in cgroupfs. Thank you to
Michal, who provided the ASCII art in the updated documentation.

To access this value:
  $ mkdir /sys/fs/cgroup/test
  $ cat /sys/fs/cgroup/test/cgroup.stat.local
  freeze_time_total 0

Ensure consistent freeze time reads with freeze_seq, a per-cgroup
sequence counter. Writes are serialized using the css_set_lock.

Signed-off-by: Tiffany Yang <ynaffit@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-22 07:50:43 -10:00
Chen Ridong
94a4acfec1 cgroup/psi: Set of->priv to NULL upon file release
Setting of->priv to NULL when the file is released enables earlier bug
detection. This allows potential bugs to manifest as NULL pointer
dereferences rather than use-after-free errors[1], which are generally more
difficult to diagnose.

[1] https://lore.kernel.org/cgroups/38ef3ff9-b380-44f0-9315-8b3714b0948d@huaweicloud.com/T/#m8a3b3f88f0ff3da5925d342e90043394f8b2091b
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-22 07:47:43 -10:00
Chen Ridong
79f919a89c cgroup: split cgroup_destroy_wq into 3 workqueues
A hung task can occur during [1] LTP cgroup testing when repeatedly
mounting/unmounting perf_event and net_prio controllers with
systemd.unified_cgroup_hierarchy=1. The hang manifests in
cgroup_lock_and_drain_offline() during root destruction.

Related case:
cgroup_fj_function_perf_event cgroup_fj_function.sh perf_event
cgroup_fj_function_net_prio cgroup_fj_function.sh net_prio

Call Trace:
	cgroup_lock_and_drain_offline+0x14c/0x1e8
	cgroup_destroy_root+0x3c/0x2c0
	css_free_rwork_fn+0x248/0x338
	process_one_work+0x16c/0x3b8
	worker_thread+0x22c/0x3b0
	kthread+0xec/0x100
	ret_from_fork+0x10/0x20

Root Cause:

CPU0                            CPU1
mount perf_event                umount net_prio
cgroup1_get_tree                cgroup_kill_sb
rebind_subsystems               // root destruction enqueues
				// cgroup_destroy_wq
// kill all perf_event css
                                // one perf_event css A is dying
                                // css A offline enqueues cgroup_destroy_wq
                                // root destruction will be executed first
                                css_free_rwork_fn
                                cgroup_destroy_root
                                cgroup_lock_and_drain_offline
                                // some perf descendants are dying
                                // cgroup_destroy_wq max_active = 1
                                // waiting for css A to die

Problem scenario:
1. CPU0 mounts perf_event (rebind_subsystems)
2. CPU1 unmounts net_prio (cgroup_kill_sb), queuing root destruction work
3. A dying perf_event CSS gets queued for offline after root destruction
4. Root destruction waits for offline completion, but offline work is
   blocked behind root destruction in cgroup_destroy_wq (max_active=1)

Solution:
Split cgroup_destroy_wq into three dedicated workqueues:
cgroup_offline_wq – Handles CSS offline operations
cgroup_release_wq – Manages resource release
cgroup_free_wq – Performs final memory deallocation

This separation eliminates blocking in the CSS free path while waiting for
offline operations to complete.

[1] https://github.com/linux-test-project/ltp/blob/master/runtest/controllers
Fixes: 334c3679ec ("cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends")
Reported-by: Gao Yingjie <gaoyingjie@uniontech.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Suggested-by: Teju Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-22 07:44:11 -10:00
Chen Ridong
4c70fb2624 cpuset: remove redundant CS_ONLINE flag
The CS_ONLINE flag was introduced prior to the CSS_ONLINE flag in the
cpuset subsystem. Currently, the flag setting sequence is as follows:

1. cpuset_css_online() sets CS_ONLINE
2. css->flags gets CSS_ONLINE set
...
3. cgroup->kill_css sets CSS_DYING
4. cpuset_css_offline() clears CS_ONLINE
5. css->flags clears CSS_ONLINE

The is_cpuset_online() check currently occurs between steps 1 and 3.
However, it would be equally safe to perform this check between steps 2
and 3, as CSS_ONLINE provides the same synchronization guarantee as
CS_ONLINE.

Since CS_ONLINE is redundant with CSS_ONLINE and provides no additional
synchronization benefits, we can safely remove it to simplify the code.

Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-13 08:14:20 -10:00
Thorsten Blum
8a013ec9cb cgroup: Replace deprecated strcpy() with strscpy()
strcpy() is deprecated; use strscpy() instead.

Link: https://github.com/KSPP/linux/issues/88
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-12 08:57:03 -10:00
JP Kobryn
eea51c6e3f cgroup: avoid null de-ref in css_rstat_exit()
css_rstat_exit() may be called asynchronously in scenarios where preceding
calls to css_rstat_init() have not completed. One such example is this
sequence below:

css_create(...)
{
	...
	init_and_link_css(css, ...);

	err = percpu_ref_init(...);
	if (err)
		goto err_free_css;
	err = cgroup_idr_alloc(...);
	if (err)
		goto err_free_css;
	err = css_rstat_init(css, ...);
	if (err)
		goto err_free_css;
	...
err_free_css:
	INIT_RCU_WORK(&css->destroy_rwork, css_free_rwork_fn);
	queue_rcu_work(cgroup_destroy_wq, &css->destroy_rwork);
	return ERR_PTR(err);
}

If any of the three goto jumps are taken, async cleanup will begin and
css_rstat_exit() will be invoked on an uninitialized css->rstat_cpu.

Avoid accessing the unitialized field by returning early in
css_rstat_exit() if this is the case.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Fixes: 5da3bfa029 ("cgroup: use separate rstat trees for each subsystem")
Cc: stable@vger.kernel.org # v6.16
Reported-by: syzbot+8d052e8b99e40bc625ed@syzkaller.appspotmail.com
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-09 08:46:32 -10:00
Waiman Long
87eba5bc5a cgroup/cpuset: Remove the unnecessary css_get/put() in cpuset_partition_write()
The css_get/put() calls in cpuset_partition_write() are unnecessary as
an active reference of the kernfs node will be taken which will prevent
its removal and guarantee the existence of the css. Only the online
check is needed.

Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-09 08:42:47 -10:00
Waiman Long
150e298ae0 cgroup/cpuset: Fix a partition error with CPU hotplug
It was found during testing that an invalid leaf partition with an
empty effective exclusive CPU list can become a valid empty partition
with no CPU afer an offline/online operation of an unrelated CPU. An
empty partition root is allowed in the special case that it has no
task in its cgroup and has distributed out all its CPUs to its child
partitions. That is certainly not the case here.

The problem is in the cpumask_subsets() test in the hotplug case
(update with no new mask) of update_parent_effective_cpumask() as it
also returns true if the effective exclusive CPU list is empty. Fix that
by addding the cpumask_empty() test to root out this exception case.
Also add the cpumask_empty() test in cpuset_hotplug_update_tasks()
to avoid calling update_parent_effective_cpumask() for this special case.

Fixes: 0c7f293efc ("cgroup/cpuset: Add cpuset.cpus.exclusive.effective for v2")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-09 08:42:28 -10:00
Waiman Long
65f97cc81b cgroup/cpuset: Use static_branch_enable_cpuslocked() on cpusets_insane_config_key
The following lockdep splat was observed.

[  812.359086] ============================================
[  812.359089] WARNING: possible recursive locking detected
[  812.359097] --------------------------------------------
[  812.359100] runtest.sh/30042 is trying to acquire lock:
[  812.359105] ffffffffa7f27420 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0xe/0x20
[  812.359131]
[  812.359131] but task is already holding lock:
[  812.359134] ffffffffa7f27420 (cpu_hotplug_lock){++++}-{0:0}, at: cpuset_write_resmask+0x98/0xa70
     :
[  812.359267] Call Trace:
[  812.359272]  <TASK>
[  812.359367]  cpus_read_lock+0x3c/0xe0
[  812.359382]  static_key_enable+0xe/0x20
[  812.359389]  check_insane_mems_config.part.0+0x11/0x30
[  812.359398]  cpuset_write_resmask+0x9f2/0xa70
[  812.359411]  cgroup_file_write+0x1c7/0x660
[  812.359467]  kernfs_fop_write_iter+0x358/0x530
[  812.359479]  vfs_write+0xabe/0x1250
[  812.359529]  ksys_write+0xf9/0x1d0
[  812.359558]  do_syscall_64+0x5f/0xe0

Since commit d74b27d63a ("cgroup/cpuset: Change cpuset_rwsem
and hotplug lock order"), the ordering of cpu hotplug lock
and cpuset_mutex had been reversed. That patch correctly
used the cpuslocked version of the static branch API to enable
cpusets_pre_enable_key and cpusets_enabled_key, but it didn't do the
same for cpusets_insane_config_key.

The cpusets_insane_config_key can be enabled in the
check_insane_mems_config() which is called from update_nodemask()
or cpuset_hotplug_update_tasks() with both cpu hotplug lock and
cpuset_mutex held. Deadlock can happen with a pending hotplug event that
tries to acquire the cpu hotplug write lock which will block further
cpus_read_lock() attempt from check_insane_mems_config(). Fix that by
switching to use static_branch_enable_cpuslocked().

Fixes: d74b27d63a ("cgroup/cpuset: Change cpuset_rwsem and hotplug lock order")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-08-09 08:41:39 -10:00
Linus Torvalds
6aee5aed2e cgroup: Changes for v6.17
- Allow css_rstat_updated() in NMI context to enable memory accounting for
   allocations in NMI context.
 
 - /proc/cgroups doesn't contain useful information for cgroup2 and was
   updated to only show v1 controllers. This unfortunately broke something in
   the wild. Add an option to bring back the old behavior to ease transition.
 
 - selftest updates and other cleanups.
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Merge tag 'cgroup-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - Allow css_rstat_updated() in NMI context to enable memory accounting
   for allocations in NMI context.

 - /proc/cgroups doesn't contain useful information for cgroup2 and was
   updated to only show v1 controllers. This unfortunately broke
   something in the wild. Add an option to bring back the old behavior
   to ease transition.

 - selftest updates and other cleanups.

* tag 'cgroup-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Add compatibility option for content of /proc/cgroups
  selftests/cgroup: fix cpu.max tests
  cgroup: llist: avoid memory tears for llist_node
  selftests: cgroup: Fix missing newline in test_zswap_writeback_one
  selftests: cgroup: Allow longer timeout for kmem_dead_cgroups cleanup
  memcg: cgroup: call css_rstat_updated irrespective of in_nmi()
  cgroup: remove per-cpu per-subsystem locks
  cgroup: make css_rstat_updated nmi safe
  cgroup: support to enable nmi-safe css_rstat_updated
  selftests: cgroup: Fix compilation on pre-cgroupns kernels
  selftests: cgroup: Optionally set up v1 environment
  selftests: cgroup: Add support for named v1 hierarchies in test_core
  selftests: cgroup_util: Add helpers for testing named v1 hierarchies
  Documentation: cgroup: add section explaining controller availability
  cgroup: Drop sock_cgroup_classid() dummy implementation
2025-07-31 16:04:19 -07:00
Linus Torvalds
beace86e61 Summary of significant series in this pull request:
- The 4 patch series "mm: ksm: prevent KSM from breaking merging of new
   VMAs" from Lorenzo Stoakes addresses an issue with KSM's
   PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for
   merging with existing adjacent VMAs.
 
 - The 4 patch series "mm/damon: introduce DAMON_STAT for simple and
   practical access monitoring" from SeongJae Park adds a new kernel module
   which simplifies the setup and usage of DAMON in production
   environments.
 
 - The 6 patch series "stop passing a writeback_control to swap/shmem
   writeout" from Christoph Hellwig is a cleanup to the writeback code
   which removes a couple of pointers from struct writeback_control.
 
 - The 7 patch series "drivers/base/node.c: optimization and cleanups"
   from Donet Tom contains largely uncorrelated cleanups to the NUMA node
   setup and management code.
 
 - The 4 patch series "mm: userfaultfd: assorted fixes and cleanups" from
   Tal Zussman does some maintenance work on the userfaultfd code.
 
 - The 5 patch series "Readahead tweaks for larger folios" from Ryan
   Roberts implements some tuneups for pagecache readahead when it is
   reading into order>0 folios.
 
 - The 4 patch series "selftests/mm: Tweaks to the cow test" from Mark
   Brown provides some cleanups and consistency improvements to the
   selftests code.
 
 - The 4 patch series "Optimize mremap() for large folios" from Dev Jain
   does that.  A 37% reduction in execution time was measured in a
   memset+mremap+munmap microbenchmark.
 
 - The 5 patch series "Remove zero_user()" from Matthew Wilcox expunges
   zero_user() in favor of the more modern memzero_page().
 
 - The 3 patch series "mm/huge_memory: vmf_insert_folio_*() and
   vmf_insert_pfn_pud() fixes" from David Hildenbrand addresses some warts
   which David noticed in the huge page code.  These were not known to be
   causing any issues at this time.
 
 - The 3 patch series "mm/damon: use alloc_migrate_target() for
   DAMOS_MIGRATE_{HOT,COLD" from SeongJae Park provides some cleanup and
   consolidation work in DAMON.
 
 - The 3 patch series "use vm_flags_t consistently" from Lorenzo Stoakes
   uses vm_flags_t in places where we were inappropriately using other
   types.
 
 - The 3 patch series "mm/memfd: Reserve hugetlb folios before
   allocation" from Vivek Kasireddy increases the reliability of large page
   allocation in the memfd code.
 
 - The 14 patch series "mm: Remove pXX_devmap page table bit and pfn_t
   type" from Alistair Popple removes several now-unneeded PFN_* flags.
 
 - The 5 patch series "mm/damon: decouple sysfs from core" from SeongJae
   Park implememnts some cleanup and maintainability work in the DAMON
   sysfs layer.
 
 - The 5 patch series "madvise cleanup" from Lorenzo Stoakes does quite a
   lot of cleanup/maintenance work in the madvise() code.
 
 - The 4 patch series "madvise anon_name cleanups" from Vlastimil Babka
   provides additional cleanups on top or Lorenzo's effort.
 
 - The 11 patch series "Implement numa node notifier" from Oscar Salvador
   creates a standalone notifier for NUMA node memory state changes.
   Previously these were lumped under the more general memory on/offline
   notifier.
 
 - The 6 patch series "Make MIGRATE_ISOLATE a standalone bit" from Zi Yan
   cleans up the pageblock isolation code and fixes a potential issue which
   doesn't seem to cause any problems in practice.
 
 - The 5 patch series "selftests/damon: add python and drgn based DAMON
   sysfs functionality tests" from SeongJae Park adds additional drgn- and
   python-based DAMON selftests which are more comprehensive than the
   existing selftest suite.
 
 - The 5 patch series "Misc rework on hugetlb faulting path" from Oscar
   Salvador fixes a rather obscure deadlock in the hugetlb fault code and
   follows that fix with a series of cleanups.
 
 - The 3 patch series "cma: factor out allocation logic from
   __cma_declare_contiguous_nid" from Mike Rapoport rationalizes and cleans
   up the highmem-specific code in the CMA allocator.
 
 - The 28 patch series "mm/migration: rework movable_ops page migration
   (part 1)" from David Hildenbrand provides cleanups and
   future-preparedness to the migration code.
 
 - The 2 patch series "mm/damon: add trace events for auto-tuned
   monitoring intervals and DAMOS quota" from SeongJae Park adds some
   tracepoints to some DAMON auto-tuning code.
 
 - The 6 patch series "mm/damon: fix misc bugs in DAMON modules" from
   SeongJae Park does that.
 
 - The 6 patch series "mm/damon: misc cleanups" from SeongJae Park also
   does what it claims.
 
 - The 4 patch series "mm: folio_pte_batch() improvements" from David
   Hildenbrand cleans up the large folio PTE batching code.
 
 - The 13 patch series "mm/damon/vaddr: Allow interleaving in
   migrate_{hot,cold} actions" from SeongJae Park facilitates dynamic
   alteration of DAMON's inter-node allocation policy.
 
 - The 3 patch series "Remove unmap_and_put_page()" from Vishal Moola
   provides a couple of page->folio conversions.
 
 - The 4 patch series "mm: per-node proactive reclaim" from Davidlohr
   Bueso implements a per-node control of proactive reclaim - beyond the
   current memcg-based implementation.
 
 - The 14 patch series "mm/damon: remove damon_callback" from SeongJae
   Park replaces the damon_callback interface with a more general and
   powerful damon_call()+damos_walk() interface.
 
 - The 10 patch series "mm/mremap: permit mremap() move of multiple VMAs"
   from Lorenzo Stoakes implements a number of mremap cleanups (of course)
   in preparation for adding new mremap() functionality: newly permit the
   remapping of multiple VMAs when the user is specifying MREMAP_FIXED.  It
   still excludes some specialized situations where this cannot be
   performed reliably.
 
 - The 3 patch series "drop hugetlb_free_pgd_range()" from Anthony Yznaga
   switches some sparc hugetlb code over to the generic version and removes
   the thus-unneeded hugetlb_free_pgd_range().
 
 - The 4 patch series "mm/damon/sysfs: support periodic and automated
   stats update" from SeongJae Park augments the present
   userspace-requested update of DAMON sysfs monitoring files.  Automatic
   update is now provided, along with a tunable to control the update
   interval.
 
 - The 4 patch series "Some randome fixes and cleanups to swapfile" from
   Kemeng Shi does what is claims.
 
 - The 4 patch series "mm: introduce snapshot_page" from Luiz Capitulino
   and David Hildenbrand provides (and uses) a means by which debug-style
   functions can grab a copy of a pageframe and inspect it locklessly
   without tripping over the races inherent in operating on the live
   pageframe directly.
 
 - The 6 patch series "use per-vma locks for /proc/pid/maps reads" from
   Suren Baghdasaryan addresses the large contention issues which can be
   triggered by reads from that procfs file.  Latencies are reduced by more
   than half in some situations.  The series also introduces several new
   selftests for the /proc/pid/maps interface.
 
 - The 6 patch series "__folio_split() clean up" from Zi Yan cleans up
   __folio_split()!
 
 - The 7 patch series "Optimize mprotect() for large folios" from Dev
   Jain provides some quite large (>3x) speedups to mprotect() when dealing
   with large folios.
 
 - The 2 patch series "selftests/mm: reuse FORCE_READ to replace "asm
   volatile("" : "+r" (XXX));" and some cleanup" from wang lian does some
   cleanup work in the selftests code.
 
 - The 3 patch series "tools/testing: expand mremap testing" from Lorenzo
   Stoakes extends the mremap() selftest in several ways, including adding
   more checking of Lorenzo's recently added "permit mremap() move of
   multiple VMAs" feature.
 
 - The 22 patch series "selftests/damon/sysfs.py: test all parameters"
   from SeongJae Park extends the DAMON sysfs interface selftest so that it
   tests all possible user-requested parameters.  Rather than the present
   minimal subset.
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Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "As usual, many cleanups. The below blurbiage describes 42 patchsets.
  21 of those are partially or fully cleanup work. "cleans up",
  "cleanup", "maintainability", "rationalizes", etc.

  I never knew the MM code was so dirty.

  "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes)
     addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly
     mapped VMAs were not eligible for merging with existing adjacent
     VMAs.

  "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park)
     adds a new kernel module which simplifies the setup and usage of
     DAMON in production environments.

  "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig)
     is a cleanup to the writeback code which removes a couple of
     pointers from struct writeback_control.

  "drivers/base/node.c: optimization and cleanups" (Donet Tom)
     contains largely uncorrelated cleanups to the NUMA node setup and
     management code.

  "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman)
     does some maintenance work on the userfaultfd code.

  "Readahead tweaks for larger folios" (Ryan Roberts)
     implements some tuneups for pagecache readahead when it is reading
     into order>0 folios.

  "selftests/mm: Tweaks to the cow test" (Mark Brown)
     provides some cleanups and consistency improvements to the
     selftests code.

  "Optimize mremap() for large folios" (Dev Jain)
     does that. A 37% reduction in execution time was measured in a
     memset+mremap+munmap microbenchmark.

  "Remove zero_user()" (Matthew Wilcox)
     expunges zero_user() in favor of the more modern memzero_page().

  "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand)
     addresses some warts which David noticed in the huge page code.
     These were not known to be causing any issues at this time.

  "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park)
     provides some cleanup and consolidation work in DAMON.

  "use vm_flags_t consistently" (Lorenzo Stoakes)
     uses vm_flags_t in places where we were inappropriately using other
     types.

  "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy)
     increases the reliability of large page allocation in the memfd
     code.

  "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple)
     removes several now-unneeded PFN_* flags.

  "mm/damon: decouple sysfs from core" (SeongJae Park)
     implememnts some cleanup and maintainability work in the DAMON
     sysfs layer.

  "madvise cleanup" (Lorenzo Stoakes)
     does quite a lot of cleanup/maintenance work in the madvise() code.

  "madvise anon_name cleanups" (Vlastimil Babka)
     provides additional cleanups on top or Lorenzo's effort.

  "Implement numa node notifier" (Oscar Salvador)
     creates a standalone notifier for NUMA node memory state changes.
     Previously these were lumped under the more general memory
     on/offline notifier.

  "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan)
     cleans up the pageblock isolation code and fixes a potential issue
     which doesn't seem to cause any problems in practice.

  "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park)
     adds additional drgn- and python-based DAMON selftests which are
     more comprehensive than the existing selftest suite.

  "Misc rework on hugetlb faulting path" (Oscar Salvador)
     fixes a rather obscure deadlock in the hugetlb fault code and
     follows that fix with a series of cleanups.

  "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport)
     rationalizes and cleans up the highmem-specific code in the CMA
     allocator.

  "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand)
     provides cleanups and future-preparedness to the migration code.

  "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park)
     adds some tracepoints to some DAMON auto-tuning code.

  "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park)
     does that.

  "mm/damon: misc cleanups" (SeongJae Park)
     also does what it claims.

  "mm: folio_pte_batch() improvements" (David Hildenbrand)
     cleans up the large folio PTE batching code.

  "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park)
     facilitates dynamic alteration of DAMON's inter-node allocation
     policy.

  "Remove unmap_and_put_page()" (Vishal Moola)
     provides a couple of page->folio conversions.

  "mm: per-node proactive reclaim" (Davidlohr Bueso)
     implements a per-node control of proactive reclaim - beyond the
     current memcg-based implementation.

  "mm/damon: remove damon_callback" (SeongJae Park)
     replaces the damon_callback interface with a more general and
     powerful damon_call()+damos_walk() interface.

  "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes)
     implements a number of mremap cleanups (of course) in preparation
     for adding new mremap() functionality: newly permit the remapping
     of multiple VMAs when the user is specifying MREMAP_FIXED. It still
     excludes some specialized situations where this cannot be performed
     reliably.

  "drop hugetlb_free_pgd_range()" (Anthony Yznaga)
     switches some sparc hugetlb code over to the generic version and
     removes the thus-unneeded hugetlb_free_pgd_range().

  "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park)
     augments the present userspace-requested update of DAMON sysfs
     monitoring files. Automatic update is now provided, along with a
     tunable to control the update interval.

  "Some randome fixes and cleanups to swapfile" (Kemeng Shi)
     does what is claims.

  "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand)
     provides (and uses) a means by which debug-style functions can grab
     a copy of a pageframe and inspect it locklessly without tripping
     over the races inherent in operating on the live pageframe
     directly.

  "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan)
     addresses the large contention issues which can be triggered by
     reads from that procfs file. Latencies are reduced by more than
     half in some situations. The series also introduces several new
     selftests for the /proc/pid/maps interface.

  "__folio_split() clean up" (Zi Yan)
     cleans up __folio_split()!

  "Optimize mprotect() for large folios" (Dev Jain)
     provides some quite large (>3x) speedups to mprotect() when dealing
     with large folios.

  "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian)
     does some cleanup work in the selftests code.

  "tools/testing: expand mremap testing" (Lorenzo Stoakes)
     extends the mremap() selftest in several ways, including adding
     more checking of Lorenzo's recently added "permit mremap() move of
     multiple VMAs" feature.

  "selftests/damon/sysfs.py: test all parameters" (SeongJae Park)
     extends the DAMON sysfs interface selftest so that it tests all
     possible user-requested parameters. Rather than the present minimal
     subset"

* tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits)
  MAINTAINERS: add missing headers to mempory policy & migration section
  MAINTAINERS: add missing file to cgroup section
  MAINTAINERS: add MM MISC section, add missing files to MISC and CORE
  MAINTAINERS: add missing zsmalloc file
  MAINTAINERS: add missing files to page alloc section
  MAINTAINERS: add missing shrinker files
  MAINTAINERS: move memremap.[ch] to hotplug section
  MAINTAINERS: add missing mm_slot.h file THP section
  MAINTAINERS: add missing interval_tree.c to memory mapping section
  MAINTAINERS: add missing percpu-internal.h file to per-cpu section
  mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info()
  selftests/damon: introduce _common.sh to host shared function
  selftests/damon/sysfs.py: test runtime reduction of DAMON parameters
  selftests/damon/sysfs.py: test non-default parameters runtime commit
  selftests/damon/sysfs.py: generalize DAMON context commit assertion
  selftests/damon/sysfs.py: generalize monitoring attributes commit assertion
  selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion
  selftests/damon/sysfs.py: test DAMOS filters commitment
  selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion
  selftests/damon/sysfs.py: test DAMOS destinations commitment
  ...
2025-07-31 14:57:54 -07:00
Linus Torvalds
d9104cec3e bpf-next-6.17
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Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf updates from Alexei Starovoitov:

 - Remove usermode driver (UMD) framework (Thomas Weißschuh)

 - Introduce Strongly Connected Component (SCC) in the verifier to
   detect loops and refine register liveness (Eduard Zingerman)

 - Allow 'void *' cast using bpf_rdonly_cast() and corresponding
   '__arg_untrusted' for global function parameters (Eduard Zingerman)

 - Improve precision for BPF_ADD and BPF_SUB operations in the verifier
   (Harishankar Vishwanathan)

 - Teach the verifier that constant pointer to a map cannot be NULL
   (Ihor Solodrai)

 - Introduce BPF streams for error reporting of various conditions
   detected by BPF runtime (Kumar Kartikeya Dwivedi)

 - Teach the verifier to insert runtime speculation barrier (lfence on
   x86) to mitigate speculative execution instead of rejecting the
   programs (Luis Gerhorst)

 - Various improvements for 'veristat' (Mykyta Yatsenko)

 - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
   improve bug detection by syzbot (Paul Chaignon)

 - Support BPF private stack on arm64 (Puranjay Mohan)

 - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
   node (Song Liu)

 - Introduce kfuncs for read-only string opreations (Viktor Malik)

 - Implement show_fdinfo() for bpf_links (Tao Chen)

 - Reduce verifier's stack consumption (Yonghong Song)

 - Implement mprog API for cgroup-bpf programs (Yonghong Song)

* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
  selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
  selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
  bpf: Add log for attaching tracing programs to functions in deny list
  bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
  bpf: Fix various typos in verifier.c comments
  bpf: Add third round of bounds deduction
  selftests/bpf: Test invariants on JSLT crossing sign
  selftests/bpf: Test cross-sign 64bits range refinement
  selftests/bpf: Update reg_bound range refinement logic
  bpf: Improve bounds when s64 crosses sign boundary
  bpf: Simplify bounds refinement from s32
  selftests/bpf: Enable private stack tests for arm64
  bpf, arm64: JIT support for private stack
  bpf: Move bpf_jit_get_prog_name() to core.c
  bpf, arm64: Fix fp initialization for exception boundary
  umd: Remove usermode driver framework
  bpf/preload: Don't select USERMODE_DRIVER
  selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
  selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
  selftests/bpf: Increase xdp data size for arm64 64K page size
  ...
2025-07-30 09:58:50 -07:00
Linus Torvalds
c64004df89 cgroup: Fixes for v6.16-rc6
An earlier commit to suppress a warning introduced a race condition where
 tasks can escape cgroup1 freezer. Revert the commit and simply remove the
 warning which was spurious to begin with.
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Merge tag 'cgroup-for-6.16-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:
 "An earlier commit to suppress a warning introduced a race condition
  where tasks can escape cgroup1 freezer. Revert the commit and simply
  remove the warning which was spurious to begin with"

* tag 'cgroup-for-6.16-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Revert "cgroup_freezer: cgroup_freezing: Check if not frozen"
  sched,freezer: Remove unnecessary warning in __thaw_task
2025-07-19 10:00:47 -07:00
Michal Koutný
646faf36d7 cgroup: Add compatibility option for content of /proc/cgroups
/proc/cgroups lists only v1 controllers by default, however, this is
only enforced since the commit af000ce852 ("cgroup: Do not report
unavailable v1 controllers in /proc/cgroups") and there is software in
the wild that uses content of /proc/cgroups to decide on availability of
v2 (sic) controllers.

Add a boottime param that can bring back the previous behavior for
setups where the check in the software cannot be changed and it causes
e.g. unintended OOMs.

Also, this patch takes out cgrp_v1_visible from cgroup1_subsys_absent()
guard since it's only important to check which hierarchy (v1 vs v2) the
subsys is attached to. This has no effect on the printed message but
the code is cleaner since cgrp_v1_visible is really about mounted
hierarchies, not the content of /proc/cgroups.

Link: https://lore.kernel.org/r/b26b60b7d0d2a5ecfd2f3c45f95f32922ed24686.camel@decadent.org.uk
Fixes: af000ce852 ("cgroup: Do not report unavailable v1 controllers in /proc/cgroups")
Fixes: a0ab145322 ("cgroup: Print message when /proc/cgroups is read on v2-only system")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-07-19 06:14:44 -10:00
Chen Ridong
14a67b42cb Revert "cgroup_freezer: cgroup_freezing: Check if not frozen"
This reverts commit cff5f49d43.

Commit cff5f49d43 ("cgroup_freezer: cgroup_freezing: Check if not
frozen") modified the cgroup_freezing() logic to verify that the FROZEN
flag is not set, affecting the return value of the freezing() function,
in order to address a warning in __thaw_task.

A race condition exists that may allow tasks to escape being frozen. The
following scenario demonstrates this issue:

CPU 0 (get_signal path)		CPU 1 (freezer.state reader)
try_to_freeze			read freezer.state
__refrigerator			freezer_read
				update_if_frozen
WRITE_ONCE(current->__state, TASK_FROZEN);
				...
				/* Task is now marked frozen */
				/* frozen(task) == true */
				/* Assuming other tasks are frozen */
				freezer->state |= CGROUP_FROZEN;
/* freezing(current) returns false */
/* because cgroup is frozen (not freezing) */
break out
__set_current_state(TASK_RUNNING);
/* Bug: Task resumes running when it should remain frozen */

The existing !frozen(p) check in __thaw_task makes the
WARN_ON_ONCE(freezing(p)) warning redundant. Removing this warning enables
reverting the commit cff5f49d43 ("cgroup_freezer: cgroup_freezing: Check
if not frozen") to resolve the issue.

The warning has been removed in the previous patch. This patch revert the
commit cff5f49d43 ("cgroup_freezer: cgroup_freezing: Check if not
frozen") to complete the fix.

Fixes: cff5f49d43 ("cgroup_freezer: cgroup_freezing: Check if not frozen")
Reported-by: Zhong Jiawei<zhongjiawei1@huawei.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-07-17 07:57:02 -10:00
Shakeel Butt
dfe25fbaed cgroup: llist: avoid memory tears for llist_node
Before the commit 36df6e3dbd ("cgroup: make css_rstat_updated nmi
safe"), the struct llist_node is expected to be private to the one
inserting the node to the lockless list or the one removing the node
from the lockless list. After the mentioned commit, the llist_node in
the rstat code is per-cpu shared between the stacked contexts i.e.
process, softirq, hardirq & nmi. It is possible the compiler may tear
the loads or stores of llist_node. Let's avoid that.

KCSAN reported the following race:

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 60 UID: 0 PID: 5425 ... 6.16.0-rc3-next-20250626 #1 NONE
 Tainted: [E]=UNSIGNED_MODULE
 Hardware name: ...
 ==================================================================
 ==================================================================
 BUG: KCSAN: data-race in css_rstat_flush / css_rstat_updated
 write to 0xffffe8fffe1c85f0 of 8 bytes by task 1061 on cpu 1:
  css_rstat_flush+0x1b8/0xeb0
  __mem_cgroup_flush_stats+0x184/0x190
  flush_memcg_stats_dwork+0x22/0x50
  process_one_work+0x335/0x630
  worker_thread+0x5f1/0x8a0
  kthread+0x197/0x340
  ret_from_fork+0xd3/0x110
  ret_from_fork_asm+0x11/0x20
 read to 0xffffe8fffe1c85f0 of 8 bytes by task 3551 on cpu 15:
  css_rstat_updated+0x81/0x180
  mod_memcg_lruvec_state+0x113/0x2d0
  __mod_lruvec_state+0x3d/0x50
  lru_add+0x21e/0x3f0
  folio_batch_move_lru+0x80/0x1b0
  __folio_batch_add_and_move+0xd7/0x160
  folio_add_lru_vma+0x42/0x50
  do_anonymous_page+0x892/0xe90
  __handle_mm_fault+0xfaa/0x1520
  handle_mm_fault+0xdc/0x350
  do_user_addr_fault+0x1dc/0x650
  exc_page_fault+0x5c/0x110
  asm_exc_page_fault+0x22/0x30
 value changed: 0xffffe8fffe18e0d0 -> 0xffffe8fffe1c85f0

$ ./scripts/faddr2line vmlinux css_rstat_flush+0x1b8/0xeb0
css_rstat_flush+0x1b8/0xeb0:
init_llist_node at include/linux/llist.h:86
(inlined by) llist_del_first_init at include/linux/llist.h:308
(inlined by) css_process_update_tree at kernel/cgroup/rstat.c:148
(inlined by) css_rstat_updated_list at kernel/cgroup/rstat.c:258
(inlined by) css_rstat_flush at kernel/cgroup/rstat.c:389

$ ./scripts/faddr2line vmlinux css_rstat_updated+0x81/0x180
css_rstat_updated+0x81/0x180:
css_rstat_updated at kernel/cgroup/rstat.c:90 (discriminator 1)

These are expected race and a simple READ_ONCE/WRITE_ONCE resolves these
reports. However let's add comments to explain the race and the need for
memory barriers if stronger guarantees are needed.

More specifically the rstat updater and the flusher can race and cause a
scenario where the stats updater skips adding the css to the lockless
list but the flusher might not see those updates done by the skipped
updater. This is benign race and the subsequent flusher will flush those
stats and at the moment there aren't any rstat users which are not fine
with this kind of race. However some future user might want more
stricter guarantee, so let's add appropriate comments to ease the job of
future users.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Fixes: 36df6e3dbd ("cgroup: make css_rstat_updated nmi safe")
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-07-17 07:41:56 -10:00
Oscar Salvador
8e1bf051c5 kernel,cpuset: use node-notifier instead of memory-notifier
cpuset is only concerned when a numa node changes its memory state, as it
needs to know the current numa nodes with memory to keep an updated
mems_allowed mask.  So stop using the memory notifier and use the new numa
node notifer instead.

Link: https://lkml.kernel.org/r/20250616135158.450136-9-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13 16:38:16 -07:00
Alexei Starovoitov
886178a33a Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf after rc3
Cross-merge BPF, perf and other fixes after downstream PRs.
It restores BPF CI to green after critical fix
commit bc4394e5e7 ("perf: Fix the throttle error of some clock events")

No conflicts.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-06-26 09:49:39 -07:00
Linus Torvalds
74b4cc9b87 cgroup: A fix for v6.16-rc2
In cgroup1 freezer, a task migrating into a frozen cgroup might not get
 frozen immediately due to the wrong operation order. Fix it.
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Merge tag 'cgroup-for-6.16-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:

 - In cgroup1 freezer, a task migrating into a frozen cgroup might not
   get frozen immediately due to the wrong operation order. Fix it.

* tag 'cgroup-for-6.16-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup,freezer: fix incomplete freezing when attaching tasks
2025-06-18 14:25:50 -07:00
Chen Ridong
37fb58a727 cgroup,freezer: fix incomplete freezing when attaching tasks
An issue was found:

	# cd /sys/fs/cgroup/freezer/
	# mkdir test
	# echo FROZEN > test/freezer.state
	# cat test/freezer.state
	FROZEN
	# sleep 1000 &
	[1] 863
	# echo 863 > test/cgroup.procs
	# cat test/freezer.state
	FREEZING

When tasks are migrated to a frozen cgroup, the freezer fails to
immediately freeze the tasks, causing the cgroup to remain in the
"FREEZING".

The freeze_task() function is called before clearing the CGROUP_FROZEN
flag. This causes the freezing() check to incorrectly return false,
preventing __freeze_task() from being invoked for the migrated task.

To fix this issue, clear the CGROUP_FROZEN state before calling
freeze_task().

Fixes: f5d39b0208 ("freezer,sched: Rewrite core freezer logic")
Cc: stable@vger.kernel.org # v6.1+
Reported-by: Zhong Jiawei <zhongjiawei1@huawei.com>
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-06-18 09:43:30 -10:00
Shakeel Butt
6af89c6ca7 cgroup: remove per-cpu per-subsystem locks
The rstat update side used to insert the cgroup whose stats are updated
in the update tree and the read side flush the update tree to get the
latest uptodate stats. The per-cpu per-subsystem locks were used to
synchronize the update and flush side. However now the update side does
not access update tree but uses per-cpu lockless lists. So there is no
need for locks to synchronize update and flush side. Let's remove them.

Suggested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Tested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-06-17 10:01:18 -10:00
Shakeel Butt
36df6e3dbd cgroup: make css_rstat_updated nmi safe
To make css_rstat_updated() able to safely run in nmi context, let's
move the rstat update tree creation at the flush side and use per-cpu
lockless lists in struct cgroup_subsys to track the css whose stats are
updated on that cpu.

The struct cgroup_subsys_state now has per-cpu lnode which needs to be
inserted into the corresponding per-cpu lhead of struct cgroup_subsys.
Since we want the insertion to be nmi safe, there can be multiple
inserters on the same cpu for the same lnode. Here multiple inserters
are from stacked contexts like softirq, hardirq and nmi.

The current llist does not provide function to protect against the
scenario where multiple inserters can use the same lnode. So, using
llist_node() out of the box is not safe for this scenario.

However we can protect against multiple inserters using the same lnode
by using the fact llist node points to itself when not on the llist and
atomically reset it and select the winner as the single inserter.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Tested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-06-17 10:01:00 -10:00
Shakeel Butt
1257b8786a cgroup: support to enable nmi-safe css_rstat_updated
Add necessary infrastructure to enable the nmi-safe execution of
css_rstat_updated(). Currently css_rstat_updated() takes a per-cpu
per-css raw spinlock to add the given css in the per-cpu per-css update
tree. However the kernel can not spin in nmi context, so we need to
remove the spinning on the raw spinlock in css_rstat_updated().

To support lockless css_rstat_updated(), let's add necessary data
structures in the css and ss structures.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Tested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-06-17 09:58:45 -10:00
Yonghong Song
9b8367b604 cgroup: Add bpf prog revisions to struct cgroup_bpf
One of key items in mprog API is revision for prog list. The revision
number will be increased if the prog list changed, e.g., attach, detach
or replace.

Add 'revisions' field to struct cgroup_bpf, representing revisions for
all cgroup related attachment types. The initial revision value is
set to 1, the same as kernel mprog implementations.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250606163136.2428732-1-yonghong.song@linux.dev
2025-06-09 16:17:11 -07:00
Linus Torvalds
def5b099a6 cgroup: A fix for v6.16-rc1
rstat per-subsystem split change skipped per-cpu allocation on UP configs;
 however even on UP, depending on config options, the size of the percpu
 struct may not be zero leading to crashes. Fix it by conditionalizing the
 per-cpu area allocation and usage on the size of the per-cpu struct.
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Merge tag 'cgroup-for-6.16-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fix from Tejun Heo:
 "The rstat per-subsystem split change skipped per-cpu allocation on UP
  configs; however even on UP, depending on config options, the size of
  the percpu struct may not be zero leading to crashes.

  Fix it by conditionalizing the per-cpu area allocation and usage on
  the size of the per-cpu struct"

* tag 'cgroup-for-6.16-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: adjust criteria for rstat subsystem cpu lock access
2025-06-03 14:12:36 -07:00
Linus Torvalds
00c010e130 - The 11 patch series "Add folio_mk_pte()" from Matthew Wilcox
simplifies the act of creating a pte which addresses the first page in a
   folio and reduces the amount of plumbing which architecture must
   implement to provide this.
 
 - The 8 patch series "Misc folio patches for 6.16" from Matthew Wilcox
   is a shower of largely unrelated folio infrastructure changes which
   clean things up and better prepare us for future work.
 
 - The 3 patch series "memory,x86,acpi: hotplug memory alignment
   advisement" from Gregory Price adds early-init code to prevent x86 from
   leaving physical memory unused when physical address regions are not
   aligned to memory block size.
 
 - The 2 patch series "mm/compaction: allow more aggressive proactive
   compaction" from Michal Clapinski provides some tuning of the (sadly,
   hard-coded (more sadly, not auto-tuned)) thresholds for our invokation
   of proactive compaction.  In a simple test case, the reduction of a guest
   VM's memory consumption was dramatic.
 
 - The 8 patch series "Minor cleanups and improvements to swap freeing
   code" from Kemeng Shi provides some code cleaups and a small efficiency
   improvement to this part of our swap handling code.
 
 - The 6 patch series "ptrace: introduce PTRACE_SET_SYSCALL_INFO API"
   from Dmitry Levin adds the ability for a ptracer to modify syscalls
   arguments.  At this time we can alter only "system call information that
   are used by strace system call tampering, namely, syscall number,
   syscall arguments, and syscall return value.
 
   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.
 
 - The 3 patch series "fs/proc: extend the PAGEMAP_SCAN ioctl to report
   guard regions" from Andrei Vagin extends the info returned by the
   PAGEMAP_SCAN ioctl against /proc/pid/pagemap.  This permits CRIU to more
   efficiently get at the info about guard regions.
 
 - The 2 patch series "Fix parameter passed to page_mapcount_is_type()"
   from Gavin Shan implements that fix.  No runtime effect is expected
   because validate_page_before_insert() happens to fix up this error.
 
 - The 3 patch series "kernel/events/uprobes: uprobe_write_opcode()
   rewrite" from David Hildenbrand basically brings uprobe text poking into
   the current decade.  Remove a bunch of hand-rolled implementation in
   favor of using more current facilities.
 
 - The 3 patch series "mm/ptdump: Drop assumption that pxd_val() is u64"
   from Anshuman Khandual provides enhancements and generalizations to the
   pte dumping code.  This might be needed when 128-bit Page Table
   Descriptors are enabled for ARM.
 
 - The 12 patch series "Always call constructor for kernel page tables"
   from Kevin Brodsky "ensures that the ctor/dtor is always called for
   kernel pgtables, as it already is for user pgtables".  This permits the
   addition of more functionality such as "insert hooks to protect page
   tables".  This change does result in various architectures performing
   unnecesary work, but this is fixed up where it is anticipated to occur.
 
 - The 9 patch series "Rust support for mm_struct, vm_area_struct, and
   mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM
   structures.
 
 - The 3 patch series "fix incorrectly disallowed anonymous VMA merges"
   from Lorenzo Stoakes takes advantage of some VMA merging opportunities
   which we've been missing for 15 years.
 
 - The 4 patch series "mm/madvise: batch tlb flushes for MADV_DONTNEED
   and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB
   flushing.  Instead of flushing each address range in the provided iovec,
   we batch the flushing across all the iovec entries.  The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.
 
 - The 6 patch series "Track node vacancy to reduce worst case allocation
   counts" from Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.  stress-ng mmap performance increased by single-digit
   percentages and the amount of unnecessarily preallocated memory was
   dramaticelly reduced.
 
 - The 3 patch series "mm/gup: Minor fix, cleanup and improvements" from
   Baoquan He removes a few unnecessary things which Baoquan noted when
   reading the code.
 
 - The 3 patch series ""Enhance sysfs handling for memory hotplug in
   weighted interleave" from Rakie Kim "enhances the weighted interleave
   policy in the memory management subsystem by improving sysfs handling,
   fixing memory leaks, and introducing dynamic sysfs updates for memory
   hotplug support".  Fixes things on error paths which we are unlikely to
   hit.
 
 - The 7 patch series "mm/damon: auto-tune DAMOS for NUMA setups
   including tiered memory" from SeongJae Park introduces new DAMOS quota
   goal metrics which eliminate the manual tuning which is required when
   utilizing DAMON for memory tiering.
 
 - The 5 patch series "mm/vmalloc.c: code cleanup and improvements" from
   Baoquan He provides cleanups and small efficiency improvements which
   Baoquan found via code inspection.
 
 - The 2 patch series "vmscan: enforce mems_effective during demotion"
   from Gregory Price "changes reclaim to respect cpuset.mems_effective
   during demotion when possible".  because "presently, reclaim explicitly
   ignores cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated." "This is useful for isolating workloads on a
   multi-tenant system from certain classes of memory more consistently."
 
 - The 2 patch series ""Clean up split_huge_pmd_locked() and remove
   unnecessary folio pointers" from Gavin Guo provides minor cleanups and
   efficiency gains in in the huge page splitting and migrating code.
 
 - The 3 patch series "Use kmem_cache for memcg alloc" from Huan Yang
   creates a slab cache for `struct mem_cgroup', yielding improved memory
   utilization.
 
 - The 4 patch series "add max arg to swappiness in memory.reclaim and
   lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness="
   argument for memory.reclaim MGLRU's lru_gen.  This directs proactive
   reclaim to reclaim from only anon folios rather than file-backed folios.
 
 - The 17 patch series "kexec: introduce Kexec HandOver (KHO)" from Mike
   Rapoport is the first step on the path to permitting the kernel to
   maintain existing VMs while replacing the host kernel via file-based
   kexec.  At this time only memblock's reserve_mem is preserved.
 
 - The 7 patch series "mm: Introduce for_each_valid_pfn()" from David
   Woodhouse provides and uses a smarter way of looping over a pfn range.
   By skipping ranges of invalid pfns.
 
 - The 2 patch series "sched/numa: Skip VMA scanning on memory pinned to
   one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless
   VMA scanning when a task is pinned a single NUMA mode.  Dramatic
   performance benefits were seen in some real world cases.
 
 - The 2 patch series "JFS: Implement migrate_folio for
   jfs_metapage_aops" from Shivank Garg addresses a warning which occurs
   during memory compaction when using JFS.
 
 - The 4 patch series "move all VMA allocation, freeing and duplication
   logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c
   into the more appropriate mm/vma.c.
 
 - The 6 patch series "mm, swap: clean up swap cache mapping helper" from
   Kairui Song provides code consolidation and cleanups related to the
   folio_index() function.
 
 - The 2 patch series "mm/gup: Cleanup memfd_pin_folios()" from Vishal
   Moola does that.
 
 - The 8 patch series "memcg: Fix test_memcg_min/low test failures" from
   Waiman Long addresses some bogus failures which are being reported by
   the test_memcontrol selftest.
 
 - The 3 patch series "eliminate mmap() retry merge, add .mmap_prepare
   hook" from Lorenzo Stoakes commences the deprecation of
   file_operations.mmap() in favor of the new
   file_operations.mmap_prepare().  The latter is more restrictive and
   prevents drivers from messing with things in ways which, amongst other
   problems, may defeat VMA merging.
 
 - The 4 patch series "memcg: decouple memcg and objcg stocks"" from
   Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's
   one.  This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.
 
 - The 6 patch series "mm/damon: minor fixups and improvements for code,
   tests, and documents" from SeongJae Park is "yet another batch of
   miscellaneous DAMON changes.  Fix and improve minor problems in code,
   tests and documents."
 
 - The 7 patch series "memcg: make memcg stats irq safe" from Shakeel
   Butt converts memcg stats to be irq safe.  Another step along the way to
   making memcg charging and stats updates NMI-safe, a BPF requirement.
 
 - The 4 patch series "Let unmap_hugepage_range() and several related
   functions take folio instead of page" from Fan Ni provides folio
   conversions in the hugetlb code.
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Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
   creating a pte which addresses the first page in a folio and reduces
   the amount of plumbing which architecture must implement to provide
   this.

 - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
   largely unrelated folio infrastructure changes which clean things up
   and better prepare us for future work.

 - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
   Price adds early-init code to prevent x86 from leaving physical
   memory unused when physical address regions are not aligned to memory
   block size.

 - "mm/compaction: allow more aggressive proactive compaction" from
   Michal Clapinski provides some tuning of the (sadly, hard-coded (more
   sadly, not auto-tuned)) thresholds for our invokation of proactive
   compaction. In a simple test case, the reduction of a guest VM's
   memory consumption was dramatic.

 - "Minor cleanups and improvements to swap freeing code" from Kemeng
   Shi provides some code cleaups and a small efficiency improvement to
   this part of our swap handling code.

 - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
   adds the ability for a ptracer to modify syscalls arguments. At this
   time we can alter only "system call information that are used by
   strace system call tampering, namely, syscall number, syscall
   arguments, and syscall return value.

   This series should have been incorporated into mm.git's "non-MM"
   branch, but I goofed.

 - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
   Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
   against /proc/pid/pagemap. This permits CRIU to more efficiently get
   at the info about guard regions.

 - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
   implements that fix. No runtime effect is expected because
   validate_page_before_insert() happens to fix up this error.

 - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
   Hildenbrand basically brings uprobe text poking into the current
   decade. Remove a bunch of hand-rolled implementation in favor of
   using more current facilities.

 - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
   Khandual provides enhancements and generalizations to the pte dumping
   code. This might be needed when 128-bit Page Table Descriptors are
   enabled for ARM.

 - "Always call constructor for kernel page tables" from Kevin Brodsky
   ensures that the ctor/dtor is always called for kernel pgtables, as
   it already is for user pgtables.

   This permits the addition of more functionality such as "insert hooks
   to protect page tables". This change does result in various
   architectures performing unnecesary work, but this is fixed up where
   it is anticipated to occur.

 - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
   Ryhl adds plumbing to permit Rust access to core MM structures.

 - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
   Stoakes takes advantage of some VMA merging opportunities which we've
   been missing for 15 years.

 - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
   SeongJae Park optimizes process_madvise()'s TLB flushing.

   Instead of flushing each address range in the provided iovec, we
   batch the flushing across all the iovec entries. The syscall's cost
   was approximately halved with a microbenchmark which was designed to
   load this particular operation.

 - "Track node vacancy to reduce worst case allocation counts" from
   Sidhartha Kumar makes the maple tree smarter about its node
   preallocation.

   stress-ng mmap performance increased by single-digit percentages and
   the amount of unnecessarily preallocated memory was dramaticelly
   reduced.

 - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
   a few unnecessary things which Baoquan noted when reading the code.

 - ""Enhance sysfs handling for memory hotplug in weighted interleave"
   from Rakie Kim "enhances the weighted interleave policy in the memory
   management subsystem by improving sysfs handling, fixing memory
   leaks, and introducing dynamic sysfs updates for memory hotplug
   support". Fixes things on error paths which we are unlikely to hit.

 - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
   from SeongJae Park introduces new DAMOS quota goal metrics which
   eliminate the manual tuning which is required when utilizing DAMON
   for memory tiering.

 - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
   provides cleanups and small efficiency improvements which Baoquan
   found via code inspection.

 - "vmscan: enforce mems_effective during demotion" from Gregory Price
   changes reclaim to respect cpuset.mems_effective during demotion when
   possible. because presently, reclaim explicitly ignores
   cpuset.mems_effective when demoting, which may cause the cpuset
   settings to violated.

   This is useful for isolating workloads on a multi-tenant system from
   certain classes of memory more consistently.

 - "Clean up split_huge_pmd_locked() and remove unnecessary folio
   pointers" from Gavin Guo provides minor cleanups and efficiency gains
   in in the huge page splitting and migrating code.

 - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
   for `struct mem_cgroup', yielding improved memory utilization.

 - "add max arg to swappiness in memory.reclaim and lru_gen" from
   Zhongkun He adds a new "max" argument to the "swappiness=" argument
   for memory.reclaim MGLRU's lru_gen.

   This directs proactive reclaim to reclaim from only anon folios
   rather than file-backed folios.

 - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
   first step on the path to permitting the kernel to maintain existing
   VMs while replacing the host kernel via file-based kexec. At this
   time only memblock's reserve_mem is preserved.

 - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
   and uses a smarter way of looping over a pfn range. By skipping
   ranges of invalid pfns.

 - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
   cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
   when a task is pinned a single NUMA mode.

   Dramatic performance benefits were seen in some real world cases.

 - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
   Garg addresses a warning which occurs during memory compaction when
   using JFS.

 - "move all VMA allocation, freeing and duplication logic to mm" from
   Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
   appropriate mm/vma.c.

 - "mm, swap: clean up swap cache mapping helper" from Kairui Song
   provides code consolidation and cleanups related to the folio_index()
   function.

 - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.

 - "memcg: Fix test_memcg_min/low test failures" from Waiman Long
   addresses some bogus failures which are being reported by the
   test_memcontrol selftest.

 - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
   Stoakes commences the deprecation of file_operations.mmap() in favor
   of the new file_operations.mmap_prepare().

   The latter is more restrictive and prevents drivers from messing with
   things in ways which, amongst other problems, may defeat VMA merging.

 - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
   the per-cpu memcg charge cache from the objcg's one.

   This is a step along the way to making memcg and objcg charging
   NMI-safe, which is a BPF requirement.

 - "mm/damon: minor fixups and improvements for code, tests, and
   documents" from SeongJae Park is yet another batch of miscellaneous
   DAMON changes. Fix and improve minor problems in code, tests and
   documents.

 - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
   stats to be irq safe. Another step along the way to making memcg
   charging and stats updates NMI-safe, a BPF requirement.

 - "Let unmap_hugepage_range() and several related functions take folio
   instead of page" from Fan Ni provides folio conversions in the
   hugetlb code.

* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
  mm: pcp: increase pcp->free_count threshold to trigger free_high
  mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
  mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
  mm/hugetlb: pass folio instead of page to unmap_ref_private()
  memcg: objcg stock trylock without irq disabling
  memcg: no stock lock for cpu hot-unplug
  memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
  memcg: make count_memcg_events re-entrant safe against irqs
  memcg: make mod_memcg_state re-entrant safe against irqs
  memcg: move preempt disable to callers of memcg_rstat_updated
  memcg: memcg_rstat_updated re-entrant safe against irqs
  mm: khugepaged: decouple SHMEM and file folios' collapse
  selftests/eventfd: correct test name and improve messages
  alloc_tag: check mem_profiling_support in alloc_tag_init
  Docs/damon: update titles and brief introductions to explain DAMOS
  selftests/damon/_damon_sysfs: read tried regions directories in order
  mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
  mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
  mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
  ...
2025-05-31 15:44:16 -07:00
JP Kobryn
c853d18706 cgroup: adjust criteria for rstat subsystem cpu lock access
Previously it was found that on uniprocessor machines the size of
raw_spinlock_t could be zero so a pre-processor conditional was used to
avoid the allocation of ss->rstat_ss_cpu_lock. The conditional did not take
into account cases where lock debugging features were enabled. Cover these
cases along with the original non-smp case by explicitly using the size of
size of the lock type as criteria for allocation/access where applicable.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Fixes: 748922dcfa "cgroup: use subsystem-specific rstat locks to avoid contention"
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202505281034.7ae1668d-lkp@intel.com
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-30 14:36:13 -10:00
Linus Torvalds
43db111107 ARM:
* Add large stage-2 mapping (THP) support for non-protected guests when
   pKVM is enabled, clawing back some performance.
 
 * Enable nested virtualisation support on systems that support it,
   though it is disabled by default.
 
 * Add UBSAN support to the standalone EL2 object used in nVHE/hVHE and
   protected modes.
 
 * Large rework of the way KVM tracks architecture features and links
   them with the effects of control bits. While this has no functional
   impact, it ensures correctness of emulation (the data is automatically
   extracted from the published JSON files), and helps dealing with the
   evolution of the architecture.
 
 * Significant changes to the way pKVM tracks ownership of pages,
   avoiding page table walks by storing the state in the hypervisor's
   vmemmap. This in turn enables the THP support described above.
 
 * New selftest checking the pKVM ownership transition rules
 
 * Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
   even if the host didn't have it.
 
 * Fixes for the address translation emulation, which happened to be
   rather buggy in some specific contexts.
 
 * Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
   from the number of counters exposed to a guest and addressing a
   number of issues in the process.
 
 * Add a new selftest for the SVE host state being corrupted by a
   guest.
 
 * Keep HCR_EL2.xMO set at all times for systems running with the
   kernel at EL2, ensuring that the window for interrupts is slightly
   bigger, and avoiding a pretty bad erratum on the AmpereOne HW.
 
 * Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
   from a pretty bad case of TLB corruption unless accesses to HCR_EL2
   are heavily synchronised.
 
 * Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
   tables in a human-friendly fashion.
 
 * and the usual random cleanups.
 
 LoongArch:
 
 * Don't flush tlb if the host supports hardware page table walks.
 
 * Add KVM selftests support.
 
 RISC-V:
 
 * Add vector registers to get-reg-list selftest
 
 * VCPU reset related improvements
 
 * Remove scounteren initialization from VCPU reset
 
 * Support VCPU reset from userspace using set_mpstate() ioctl
 
 x86:
 
 * Initial support for TDX in KVM.  This finally makes it possible to use the
   TDX module to run confidential guests on Intel processors.  This is quite a
   large series, including support for private page tables (managed by the
   TDX module and mirrored in KVM for efficiency), forwarding some TDVMCALLs
   to userspace, and handling several special VM exits from the TDX module.
 
   This has been in the works for literally years and it's not really possible
   to describe everything here, so I'll defer to the various merge commits
   up to and including commit 7bcf7246c4 ("Merge branch 'kvm-tdx-finish-initial'
   into HEAD").
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "As far as x86 goes this pull request "only" includes TDX host support.

  Quotes are appropriate because (at 6k lines and 100+ commits) it is
  much bigger than the rest, which will come later this week and
  consists mostly of bugfixes and selftests. s390 changes will also come
  in the second batch.

  ARM:

   - Add large stage-2 mapping (THP) support for non-protected guests
     when pKVM is enabled, clawing back some performance.

   - Enable nested virtualisation support on systems that support it,
     though it is disabled by default.

   - Add UBSAN support to the standalone EL2 object used in nVHE/hVHE
     and protected modes.

   - Large rework of the way KVM tracks architecture features and links
     them with the effects of control bits. While this has no functional
     impact, it ensures correctness of emulation (the data is
     automatically extracted from the published JSON files), and helps
     dealing with the evolution of the architecture.

   - Significant changes to the way pKVM tracks ownership of pages,
     avoiding page table walks by storing the state in the hypervisor's
     vmemmap. This in turn enables the THP support described above.

   - New selftest checking the pKVM ownership transition rules

   - Fixes for FEAT_MTE_ASYNC being accidentally advertised to guests
     even if the host didn't have it.

   - Fixes for the address translation emulation, which happened to be
     rather buggy in some specific contexts.

   - Fixes for the PMU emulation in NV contexts, decoupling PMCR_EL0.N
     from the number of counters exposed to a guest and addressing a
     number of issues in the process.

   - Add a new selftest for the SVE host state being corrupted by a
     guest.

   - Keep HCR_EL2.xMO set at all times for systems running with the
     kernel at EL2, ensuring that the window for interrupts is slightly
     bigger, and avoiding a pretty bad erratum on the AmpereOne HW.

   - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers
     from a pretty bad case of TLB corruption unless accesses to HCR_EL2
     are heavily synchronised.

   - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS
     tables in a human-friendly fashion.

   - and the usual random cleanups.

  LoongArch:

   - Don't flush tlb if the host supports hardware page table walks.

   - Add KVM selftests support.

  RISC-V:

   - Add vector registers to get-reg-list selftest

   - VCPU reset related improvements

   - Remove scounteren initialization from VCPU reset

   - Support VCPU reset from userspace using set_mpstate() ioctl

  x86:

   - Initial support for TDX in KVM.

     This finally makes it possible to use the TDX module to run
     confidential guests on Intel processors. This is quite a large
     series, including support for private page tables (managed by the
     TDX module and mirrored in KVM for efficiency), forwarding some
     TDVMCALLs to userspace, and handling several special VM exits from
     the TDX module.

     This has been in the works for literally years and it's not really
     possible to describe everything here, so I'll defer to the various
     merge commits up to and including commit 7bcf7246c4 ('Merge
     branch 'kvm-tdx-finish-initial' into HEAD')"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (248 commits)
  x86/tdx: mark tdh_vp_enter() as __flatten
  Documentation: virt/kvm: remove unreferenced footnote
  RISC-V: KVM: lock the correct mp_state during reset
  KVM: arm64: Fix documentation for vgic_its_iter_next()
  KVM: arm64: np-guest CMOs with PMD_SIZE fixmap
  KVM: arm64: Stage-2 huge mappings for np-guests
  KVM: arm64: Add a range to pkvm_mappings
  KVM: arm64: Convert pkvm_mappings to interval tree
  KVM: arm64: Add a range to __pkvm_host_test_clear_young_guest()
  KVM: arm64: Add a range to __pkvm_host_wrprotect_guest()
  KVM: arm64: Add a range to __pkvm_host_unshare_guest()
  KVM: arm64: Add a range to __pkvm_host_share_guest()
  KVM: arm64: Introduce for_each_hyp_page
  KVM: arm64: Handle huge mappings for np-guest CMOs
  KVM: arm64: nv: Release faulted-in VNCR page from mmu_lock critical section
  KVM: arm64: nv: Handle TLBI S1E2 for VNCR invalidation with mmu_lock held
  KVM: arm64: nv: Hold mmu_lock when invalidating VNCR SW-TLB before translating
  RISC-V: KVM: add KVM_CAP_RISCV_MP_STATE_RESET
  RISC-V: KVM: Remove scounteren initialization
  KVM: RISC-V: remove unnecessary SBI reset state
  ...
2025-05-29 08:10:01 -07:00
Linus Torvalds
3b66e6b3c0 cgroup: Changes for v6.16
- cgroup rstat shared the tracking tree across all controlers with the
   rationale being that a cgroup which is using one resource is likely to be
   using other resources at the same time (ie. if something is allocating
   memory, it's probably consuming CPU cycles). However, this turned out to
   not scale very well especially with memcg using rstat for internal
   operations which made memcg stat read and flush patterns substantially
   different from other controllers. JP Kobryn split the rstat tree per
   controller.
 
 - cgroup BPF support was hooking into cgroup init/exit paths directly.
   Convert them to use a notifier chain instead so that other usages can be
   added easily. The two of the patches which implement this are mislabeled
   as belonging to sched_ext instead of cgroup. Sorry.
 
 - Relatively minor cpuset updates.
 
 - Documentation updates.
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Merge tag 'cgroup-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - cgroup rstat shared the tracking tree across all controllers with the
   rationale being that a cgroup which is using one resource is likely
   to be using other resources at the same time (ie. if something is
   allocating memory, it's probably consuming CPU cycles).

   However, this turned out to not scale very well especially with memcg
   using rstat for internal operations which made memcg stat read and
   flush patterns substantially different from other controllers. JP
   Kobryn split the rstat tree per controller.

 - cgroup BPF support was hooking into cgroup init/exit paths directly.

   Convert them to use a notifier chain instead so that other usages can
   be added easily. The two of the patches which implement this are
   mislabeled as belonging to sched_ext instead of cgroup. Sorry.

 - Relatively minor cpuset updates

 - Documentation updates

* tag 'cgroup-for-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (23 commits)
  sched_ext: Convert cgroup BPF support to use cgroup_lifetime_notifier
  sched_ext: Introduce cgroup_lifetime_notifier
  cgroup: Minor reorganization of cgroup_create()
  cgroup, docs: cpu controller's interaction with various scheduling policies
  cgroup, docs: convert space indentation to tab indentation
  cgroup: avoid per-cpu allocation of size zero rstat cpu locks
  cgroup, docs: be specific about bandwidth control of rt processes
  cgroup: document the rstat per-cpu initialization
  cgroup: helper for checking rstat participation of css
  cgroup: use subsystem-specific rstat locks to avoid contention
  cgroup: use separate rstat trees for each subsystem
  cgroup: compare css to cgroup::self in helper for distingushing css
  cgroup: warn on rstat usage by early init subsystems
  cgroup/cpuset: drop useless cpumask_empty() in compute_effective_exclusive_cpumask()
  cgroup/rstat: Improve cgroup_rstat_push_children() documentation
  cgroup: fix goto ordering in cgroup_init()
  cgroup: fix pointer check in css_rstat_init()
  cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs
  cgroup/cpuset: Fix obsolete comment in cpuset_css_offline()
  cgroup/cpuset: Always use cpu_active_mask
  ...
2025-05-27 20:59:53 -07:00
Paolo Bonzini
85502b2214 LoongArch KVM changes for v6.16
1. Don't flush tlb if HW PTW supported.
 2. Add LoongArch KVM selftests support.
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Merge tag 'loongarch-kvm-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD

LoongArch KVM changes for v6.16

1. Don't flush tlb if HW PTW supported.
2. Add LoongArch KVM selftests support.
2025-05-26 16:12:13 -04:00
Tejun Heo
82648b8b2a sched_ext: Convert cgroup BPF support to use cgroup_lifetime_notifier
Replace explicit cgroup_bpf_inherit/offline() calls from cgroup
creation/destruction paths with notification callback registered on
cgroup_lifetime_notifier.

Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-22 09:20:19 -10:00
Tejun Heo
9e8c67a9e5 sched_ext: Introduce cgroup_lifetime_notifier
Other subsystems may make use of the cgroup hierarchy with the cgroup_bpf
support being one such example. For such a feature, it's useful to be able
to hook into cgroup creation and destruction paths to perform
feature-specific initializations and cleanups.

Add cgroup_lifetime_notifier which generates CGROUP_LIFETIME_ONLINE and
CGROUP_LIFETIME_OFFLINE events whenever cgroups are created and destroyed,
respectively.

The next patch will convert cgroup_bpf to use the new notifier and other
uses are planned.

Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-22 09:20:11 -10:00
Tejun Heo
cd22cbad1b cgroup: Minor reorganization of cgroup_create()
cgroup_bpf init and exit handling will be moved to a notifier chain. In
prepartion, reorganize cgroup_create() a bit so that the new cgroup is fully
initialized before any outside changes are made.

- cgrp->ancestors[] initialization and the hierarchical nr_descendants and
  nr_frozen_descendants updates were in the same loop. Separate them out and
  do the former earlier and do the latter later.

- Relocate cgroup_bpf_inherit() call so that it's after all cgroup
  initializations are complete.

No visible behavior changes expected.

Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-22 09:19:57 -10:00
JP Kobryn
731bdd9746 cgroup: avoid per-cpu allocation of size zero rstat cpu locks
Subsystem rstat locks are dynamically allocated per-cpu. It was discovered
that a panic can occur during this allocation when the lock size is zero.
This is the case on non-smp systems, since arch_spinlock_t is defined as an
empty struct. Prevent this allocation when !CONFIG_SMP by adding a
pre-processor conditional around the affected block.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Reported-by: Klara Modin <klarasmodin@gmail.com>
Fixes: 748922dcfa ("cgroup: use subsystem-specific rstat locks to avoid contention")
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-21 15:54:58 -10:00
JP Kobryn
93b35663f2 cgroup: helper for checking rstat participation of css
There are a few places where a conditional check is performed to validate a
given css on its rstat participation. This new helper tries to make the
code more readable where this check is performed.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-19 10:29:49 -10:00
JP Kobryn
748922dcfa cgroup: use subsystem-specific rstat locks to avoid contention
It is possible to eliminate contention between subsystems when
updating/flushing stats by using subsystem-specific locks. Let the existing
rstat locks be dedicated to the cgroup base stats and rename them to
reflect that. Add similar locks to the cgroup_subsys struct for use with
individual subsystems.

Lock initialization is done in the new function ss_rstat_init(ss) which
replaces cgroup_rstat_boot(void). If NULL is passed to this function, the
global base stat locks will be initialized. Otherwise, the subsystem locks
will be initialized.

Change the existing lock helper functions to accept a reference to a css.
Then within these functions, conditionally select the appropriate locks
based on the subsystem affiliation of the given css. Add helper functions
for this selection routine to avoid repeated code.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-19 10:29:42 -10:00
JP Kobryn
5da3bfa029 cgroup: use separate rstat trees for each subsystem
Different subsystems may call cgroup_rstat_updated() within the same
cgroup, resulting in a tree of pending updates from multiple subsystems.
When one of these subsystems is flushed via cgroup_rstat_flushed(), all
other subsystems with pending updates on the tree will also be flushed.

Change the paradigm of having a single rstat tree for all subsystems to
having separate trees for each subsystem. This separation allows for
subsystems to perform flushes without the side effects of other subsystems.
As an example, flushing the cpu stats will no longer cause the memory stats
to be flushed and vice versa.

In order to achieve subsystem-specific trees, change the tree node type
from cgroup to cgroup_subsys_state pointer. Then remove those pointers from
the cgroup and instead place them on the css. Finally, change update/flush
functions to make use of the different node type (css). These changes allow
a specific subsystem to be associated with an update or flush. Separate
rstat trees will now exist for each unique subsystem.

Since updating/flushing will now be done at the subsystem level, there is
no longer a need to keep track of updated css nodes at the cgroup level.
The list management of these nodes done within the cgroup (rstat_css_list
and related) has been removed accordingly.

Conditional guards for checking validity of a given css were placed within
css_rstat_updated/flush() to prevent undefined behavior occuring from kfunc
usage in bpf programs. Guards were also placed within css_rstat_init/exit()
in order to help consolidate calls to them. At call sites for all four
functions, the existing guards were removed.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-19 10:28:59 -10:00
JP Kobryn
541a4219bd cgroup: compare css to cgroup::self in helper for distingushing css
Adjust the implementation of css_is_cgroup() so that it compares the given
css to cgroup::self. Rename the function to css_is_self() in order to
reflect that. Change the existing css->ss NULL check to a warning in the
true branch. Finally, adjust call sites to use the new function name.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-19 10:21:24 -10:00
JP Kobryn
b2713a5ad3 cgroup: warn on rstat usage by early init subsystems
An early init subsystem that attempts to make use of rstat can lead to
failures during early boot. The reason for this is the timing in which the
css's of the root cgroup have css_online() invoked on them. At the point of
this call, there is a stated assumption that a cgroup has "successfully
completed all allocations" [0]. An example of a subsystem that relies on
the previously mentioned assumption [0] is the memory subsystem. Within its
implementation of css_online(), work is queued to asynchronously begin
flushing via rstat. In the early init path for a given subsystem, having
rstat enabled leads to this sequence:

cgroup_init_early()
	for_each_subsys(ss, ssid)
	    if (ss->early_init)
		cgroup_init_subsys(ss, true)

cgroup_init_subsys(ss, early_init)
    css = ss->css_alloc(...)
    init_and_link_css(css, ss, ...)
    ...
    online_css(css)

online_css(css)
    ss = css->ss
    ss->css_online(css)

Continuing to use the memory subsystem as an example, the issue with this
sequence is that css_rstat_init() has not been called yet. This means there
is now a race between the pending async work to flush rstat and the call to
css_rstat_init(). So a flush can occur within the given cgroup while the
rstat fields are not initialized.

Since we are in the early init phase, the rstat fields cannot be
initialized because they require per-cpu allocations. So it's not possible
to have css_rstat_init() called early enough (before online_css()). This
patch treats the combination of early init and rstat the same as as other
invalid conditions.

[0] Documentation/admin-guide/cgroup-v1/cgroups.rst (section: css_online)

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-19 10:18:29 -10:00
Gregory Price
7d709f49ba vmscan,cgroup: apply mems_effective to reclaim
It is possible for a reclaimer to cause demotions of an lruvec belonging
to a cgroup with cpuset.mems set to exclude some nodes.  Attempt to apply
this limitation based on the lruvec's memcg and prevent demotion.

Notably, this may still allow demotion of shared libraries or any memory
first instantiated in another cgroup.  This means cpusets still cannot
cannot guarantee complete isolation when demotion is enabled, and the docs
have been updated to reflect this.

This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently - with the noted exceptions.

Note on locking:

The cgroup_get_e_css reference protects the css->effective_mems, and calls
of this interface would be subject to the same race conditions associated
with a non-atomic access to cs->effective_mems.

So while this interface cannot make strong guarantees of correctness, it
can therefore avoid taking a global or rcu_read_lock for performance.

Link: https://lkml.kernel.org/r/20250424202806.52632-3-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12 23:50:33 -07:00
Gregory Price
8adce08577 cpuset: rename cpuset_node_allowed to cpuset_current_node_allowed
Patch series "vmscan: enforce mems_effective during demotion", v5.

Change reclaim to respect cpuset.mems_effective during demotion when
possible.  Presently, reclaim explicitly ignores cpuset.mems_effective
when demoting, which may cause the cpuset settings to violated.

Implement cpuset_node_allowed() to check the cpuset.mems_effective
associated wih the mem_cgroup of the lruvec being scanned.  This only
applies to cgroup/cpuset v2, as cpuset exists in a different hierarchy
than mem_cgroup in v1.

This requires renaming the existing cpuset_node_allowed() to be
cpuset_current_now_allowed() - which is more descriptive anyway - to
implement the new cpuset_node_allowed() which takes a target cgroup.


This patch (of 2):

Rename cpuset_node_allowed to reflect that the function checks the current
task's cpuset.mems.  This allows us to make a new cpuset_node_allowed
function that checks a target cgroup's cpuset.mems.

Link: https://lkml.kernel.org/r/20250424202806.52632-1-gourry@gourry.net
Link: https://lkml.kernel.org/r/20250424202806.52632-2-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Acked-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12 23:50:33 -07:00
Waiman Long
39b5ef791d cgroup/cpuset: Extend kthread_is_per_cpu() check to all PF_NO_SETAFFINITY tasks
Commit ec5fbdfb99 ("cgroup/cpuset: Enable update_tasks_cpumask()
on top_cpuset") enabled us to pull CPUs dedicated to child partitions
from tasks in top_cpuset by ignoring per cpu kthreads. However, there
can be other kthreads that are not per cpu but have PF_NO_SETAFFINITY
flag set to indicate that we shouldn't mess with their CPU affinity.
For other kthreads, their affinity will be changed to skip CPUs dedicated
to child partitions whether it is an isolating or a scheduling one.

As all the per cpu kthreads have PF_NO_SETAFFINITY set, the
PF_NO_SETAFFINITY tasks are essentially a superset of per cpu kthreads.
Fix this issue by dropping the kthread_is_per_cpu() check and checking
the PF_NO_SETAFFINITY flag instead.

Fixes: ec5fbdfb99 ("cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset")
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-09 07:35:14 -10:00
Yury Norov
225c0360a8 cgroup/cpuset: drop useless cpumask_empty() in compute_effective_exclusive_cpumask()
Empty cpumasks can't intersect with any others. Therefore, testing for
non-emptyness is useless.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-05-09 07:32:19 -10:00
Waiman Long
8f52633cf5 cgroup/rstat: Improve cgroup_rstat_push_children() documentation
The cgroup_rstat_push_children() function converts a set of
updated_children lists from different cgroups into a single ordered
list of cgroups to be flushed via the rstat_flush_next pointer.
The algorithm used isn't that well illustrated and it takes time to
grasp what it is doing. Improve the embedded documentation and variable
names to better illustrate the transformation process and make the code
easier to understand.

Also cgroup_rstat_lock must be held for the whole duration
from where the rstat_flush_next list is being constructed in
cgroup_rstat_push_children() to when it is consumed later in
css_rstat_flush(). Otherwise, list corruption can happen leading to
system crash as reported in [1]. In this particular case, the branch
being used has commit 093c8812de ("cgroup: rstat: Cleanup flushing
functions and locking") which breaks this rule, but is missing the fix
commit 7d6c63c319 ("cgroup: rstat: call cgroup_rstat_updated_list
with cgroup_rstat_lock") that fixes it.

This patch has no functional change.

[1] https://lore.kernel.org/lkml/BY5PR04MB68495E9E8A46CA9614D62669BCBB2@BY5PR04MB6849.namprd04.prod.outlook.com/

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-25 09:45:16 -10:00
JP Kobryn
f304da9134 cgroup: fix goto ordering in cgroup_init()
Go to the appropriate section labels when css_rstat_init() or
psi_cgroup_alloc() fails.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Fixes: a97915559f ("cgroup: change rstat function signatures from cgroup-based to css-based")
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-24 08:36:57 -10:00
Paolo Bonzini
45eb29140e Merge branch 'kvm-fixes-6.15-rc4' into HEAD
* Single fix for broken usage of 'multi-MIDR' infrastructure in PI
  code, adding an open-coded erratum check for Cavium ThunderX

* Bugfixes from a planned posted interrupt rework

* Do not use kvm_rip_read() unconditionally to cater for guests
  with inaccessible register state.
2025-04-24 13:39:34 -04:00
JP Kobryn
7efbc8f2f9 cgroup: fix pointer check in css_rstat_init()
In css_rstat_init() allocations are done for the cgroup's pointers
rstat_cpu and rstat_base_cpu. Make sure the allocation checks are
consistent with what they are allocating.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-21 08:27:33 -10:00
T.J. Mercier
1bf67c8fdb cgroup/cpuset-v1: Add missing support for cpuset_v2_mode
Android has mounted the v1 cpuset controller using filesystem type
"cpuset" (not "cgroup") since 2015 [1], and depends on the resulting
behavior where the controller name is not added as a prefix for cgroupfs
files. [2]

Later, a problem was discovered where cpu hotplug onlining did not
affect the cpuset/cpus files, which Android carried an out-of-tree patch
to address for a while. An attempt was made to upstream this patch, but
the recommendation was to use the "cpuset_v2_mode" mount option
instead. [3]

An effort was made to do so, but this fails with "cgroup: Unknown
parameter 'cpuset_v2_mode'" because commit e1cba4b85d ("cgroup: Add
mount flag to enable cpuset to use v2 behavior in v1 cgroup") did not
update the special cased cpuset_mount(), and only the cgroup (v1)
filesystem type was updated.

Add parameter parsing to the cpuset filesystem type so that
cpuset_v2_mode works like the cgroup filesystem type:

$ mkdir /dev/cpuset
$ mount -t cpuset -ocpuset_v2_mode none /dev/cpuset
$ mount|grep cpuset
none on /dev/cpuset type cgroup (rw,relatime,cpuset,noprefix,cpuset_v2_mode,release_agent=/sbin/cpuset_release_agent)

[1] b769c8d24f
[2] https://cs.android.com/android/platform/superproject/main/+/main:system/core/libprocessgroup/setup/cgroup_map_write.cpp;drc=2dac5d89a0f024a2d0cc46a80ba4ee13472f1681;l=192
[3] https://lore.kernel.org/lkml/f795f8be-a184-408a-0b5a-553d26061385@redhat.com/T/

Fixes: e1cba4b85d ("cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup")
Signed-off-by: T.J. Mercier <tjmercier@google.com>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-17 07:32:53 -10:00
gaoxu
87c259a7a3 cgroup: Fix compilation issue due to cgroup_mutex not being exported
When adding folio_memcg function call in the zram module for
Android16-6.12, the following error occurs during compilation:
ERROR: modpost: "cgroup_mutex" [../soc-repo/zram.ko] undefined!

This error is caused by the indirect call to lockdep_is_held(&cgroup_mutex)
within folio_memcg. The export setting for cgroup_mutex is controlled by
the CONFIG_PROVE_RCU macro. If CONFIG_LOCKDEP is enabled while
CONFIG_PROVE_RCU is not, this compilation error will occur.

To resolve this issue, add a parallel macro CONFIG_LOCKDEP control to
ensure cgroup_mutex is properly exported when needed.

Signed-off-by: gao xu <gaoxu2@honor.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-17 06:27:31 -10:00
Linus Torvalds
e37f72b3b4 cgroup: Fixes for v6.15-rc1
- A number of cpuset remote partition related fixes and cleanups along with
   selftest updates.
 
 - A change from this merge window made cgroup_rstat_updated_list() called
   outside cgroup_rstat_lock leading to list corruptions. Fix it by
   relocating the call inside the lock.
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Merge tag 'cgroup-for-6.15-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - A number of cpuset remote partition related fixes and cleanups along
   with selftest updates.

 - A change from this merge window made cgroup_rstat_updated_list()
   called outside cgroup_rstat_lock leading to list corruptions. Fix it
   by relocating the call inside the lock.

* tag 'cgroup-for-6.15-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Fix race between newly created partition and dying one
  cgroup: rstat: call cgroup_rstat_updated_list with cgroup_rstat_lock
  selftest/cgroup: Add a remote partition transition test to test_cpuset_prs.sh
  selftest/cgroup: Clean up and restructure test_cpuset_prs.sh
  selftest/cgroup: Update test_cpuset_prs.sh to use | as effective CPUs and state separator
  cgroup/cpuset: Remove unneeded goto in sched_partition_write() and rename it
  cgroup/cpuset: Code cleanup and comment update
  cgroup/cpuset: Don't allow creation of local partition over a remote one
  cgroup/cpuset: Remove remote_partition_check() & make update_cpumasks_hier() handle remote partition
  cgroup/cpuset: Fix error handling in remote_partition_disable()
  cgroup/cpuset: Fix incorrect isolated_cpus update in update_parent_effective_cpumask()
2025-04-08 12:15:05 -07:00
Waiman Long
86888c7bd1 cgroup/cpuset: Add warnings to catch inconsistency in exclusive CPUs
Add WARN_ON_ONCE() statements whenever new exclusive CPUs are being
added to a partition root to catch inconsistency in the way exclusive
CPUs are being handled in the cpuset code.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-07 12:05:09 -10:00
Waiman Long
6e6f9170dc cgroup/cpuset: Fix obsolete comment in cpuset_css_offline()
Move the partition disablement comment from cpuset_css_offline()
to cpuset_css_killed() and reword it to remove the remnant of
sched.partition.

Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-07 12:04:58 -10:00
Waiman Long
7a0aabd9ce cgroup/cpuset: Always use cpu_active_mask
The current cpuset code uses both cpu_active_mask and cpu_online_mask
and it can be confusing which one should be used if we need to update
the code.

The top_cpuset is always synchronized to cpu_active_mask and we should
avoid using cpu_online_mask as much as possible. An active CPU is always
an online CPU, but not vice versa. cpu_active_mask and cpu_online_mask
can differ during hotplug operations.

A CPU is marked active at the last stage of CPU bringup (CPUHP_AP_ACTIVE).
It is also the stage where cpuset hotplug code will be called to update
the sched domains so that the scheduler can move a normal task to a
newly active CPU or remove tasks away from a newly inactivated CPU. The
online bit is set much earlier in the CPU bringup process and cleared
much later in CPU teardown.

If cpu_online_mask is used while a hotunplug operation is happening in
parallel, we may leave an offline CPU in cpu_allowed or have a higher
chance of leaving an offline CPU in some other masks.  Avoid this
problem by always using cpu_active_mask in the cpuset code and leave
a comment as to why the use of cpu_online_mask is discouraged.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-07 12:04:51 -10:00
Paolo Bonzini
fd02aa45bd Merge branch 'kvm-tdx-initial' into HEAD
This large commit contains the initial support for TDX in KVM.  All x86
parts enable the host-side hypercalls that KVM uses to talk to the TDX
module, a software component that runs in a special CPU mode called SEAM
(Secure Arbitration Mode).

The series is in turn split into multiple sub-series, each with a separate
merge commit:

- Initialization: basic setup for using the TDX module from KVM, plus
  ioctls to create TDX VMs and vCPUs.

- MMU: in TDX, private and shared halves of the address space are mapped by
  different EPT roots, and the private half is managed by the TDX module.
  Using the support that was added to the generic MMU code in 6.14,
  add support for TDX's secure page tables to the Intel side of KVM.
  Generic KVM code takes care of maintaining a mirror of the secure page
  tables so that they can be queried efficiently, and ensuring that changes
  are applied to both the mirror and the secure EPT.

- vCPU enter/exit: implement the callbacks that handle the entry of a TDX
  vCPU (via the SEAMCALL TDH.VP.ENTER) and the corresponding save/restore
  of host state.

- Userspace exits: introduce support for guest TDVMCALLs that KVM forwards to
  userspace.  These correspond to the usual KVM_EXIT_* "heavyweight vmexits"
  but are triggered through a different mechanism, similar to VMGEXIT for
  SEV-ES and SEV-SNP.

- Interrupt handling: support for virtual interrupt injection as well as
  handling VM-Exits that are caused by vectored events.  Exclusive to
  TDX are machine-check SMIs, which the kernel already knows how to
  handle through the kernel machine check handler (commit 7911f145de,
  "x86/mce: Implement recovery for errors in TDX/SEAM non-root mode")

- Loose ends: handling of the remaining exits from the TDX module, including
  EPT violation/misconfig and several TDVMCALL leaves that are handled in
  the kernel (CPUID, HLT, RDMSR/WRMSR, GetTdVmCallInfo); plus returning
  an error or ignoring operations that are not supported by TDX guests

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-04-07 07:36:33 -04:00
Thomas Gleixner
8fa7292fee treewide: Switch/rename to timer_delete[_sync]()
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-04-05 10:30:12 +02:00
JP Kobryn
a97915559f cgroup: change rstat function signatures from cgroup-based to css-based
This non-functional change serves as preparation for moving to
subsystem-based rstat trees. To simplify future commits, change the
signatures of existing cgroup-based rstat functions to become css-based and
rename them to reflect that.

Though the signatures have changed, the implementations have not. Within
these functions use the css->cgroup pointer to obtain the associated cgroup
and allow code to function the same just as it did before this patch. At
applicable call sites, pass the subsystem-specific css pointer as an
argument or pass a pointer to cgroup::self if not in subsystem context.

Note that cgroup_rstat_updated_list() and cgroup_rstat_push_children()
are not altered yet since there would be a larger amount of css to
cgroup conversions which may overcomplicate the code at this
intermediate phase.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-04 10:06:25 -10:00
JP Kobryn
845a724580 cgroup: add helper for checking when css is cgroup::self
The cgroup struct has a css field called "self". The main difference
between this css and the others found in the cgroup::subsys array is that
cgroup::self has a NULL subsystem pointer. There are several places where
checks are performed to determine whether the css in question is
cgroup::self or not. Instead of accessing css->ss directly, introduce a
helper function that shows the intent and use where applicable.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-04 10:01:22 -10:00
JP Kobryn
f6e9a26e2d cgroup: move rstat base stat objects into their own struct
This non-functional change serves as preparation for moving to
subsystem-based rstat trees. The base stats are not an actual subsystem,
but in future commits they will have exclusive rstat trees just as other
subsystems will.

Moving the base stat objects into a new struct allows the cgroup_rstat_cpu
struct to become more compact since it now only contains the minimum amount
of pointers needed for rstat participation. Subsystems will (in future
commits) make use of the compact cgroup_rstat_cpu struct while avoiding the
memory overhead of the base stat objects which they will not use.

An instance of the new struct cgroup_rstat_base_cpu was placed on the
cgroup struct so it can retain ownership of these base stats common to all
cgroups. A helper function was added for looking up the cpu-specific base
stats of a given cgroup. Finally, initialization and variable names were
adjusted where applicable.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-04 10:00:53 -10:00
Waiman Long
a22b3d54de cgroup/cpuset: Fix race between newly created partition and dying one
There is a possible race between removing a cgroup diectory that is
a partition root and the creation of a new partition.  The partition
to be removed can be dying but still online, it doesn't not currently
participate in checking for exclusive CPUs conflict, but the exclusive
CPUs are still there in subpartitions_cpus and isolated_cpus. These
two cpumasks are global states that affect the operation of cpuset
partitions. The exclusive CPUs in dying cpusets will only be removed
when cpuset_css_offline() function is called after an RCU delay.

As a result, it is possible that a new partition can be created with
exclusive CPUs that overlap with those of a dying one. When that dying
partition is finally offlined, it removes those overlapping exclusive
CPUs from subpartitions_cpus and maybe isolated_cpus resulting in an
incorrect CPU configuration.

This bug was found when a warning was triggered in
remote_partition_disable() during testing because the subpartitions_cpus
mask was empty.

One possible way to fix this is to iterate the dying cpusets as well and
avoid using the exclusive CPUs in those dying cpusets. However, this
can still cause random partition creation failures or other anomalies
due to racing. A better way to fix this race is to reset the partition
state at the moment when a cpuset is being killed.

Introduce a new css_killed() CSS function pointer and call it, if
defined, before setting CSS_DYING flag in kill_css(). Also update the
css_is_dying() helper to use the CSS_DYING flag introduced by commit
33c35aa481 ("cgroup: Prevent kill_css() from being called more than
once") for proper synchronization.

Add a new cpuset_css_killed() function to reset the partition state of
a valid partition root if it is being killed.

Fixes: ee8dde0cd2 ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-01 21:46:22 -10:00
Linus Torvalds
2cd5769fb0 Driver core updates for 6.15-rc1
Here is the big set of driver core updates for 6.15-rc1.  Lots of stuff
 happened this development cycle, including:
   - kernfs scaling changes to make it even faster thanks to rcu
   - bin_attribute constify work in many subsystems
   - faux bus minor tweaks for the rust bindings
   - rust binding updates for driver core, pci, and platform busses,
     making more functionaliy available to rust drivers.  These are all
     due to people actually trying to use the bindings that were in 6.14.
   - make Rafael and Danilo full co-maintainers of the driver core
     codebase
   - other minor fixes and updates.
 
 This has been in linux-next for a while now, with the only reported
 issue being some merge conflicts with the rust tree.  Depending on which
 tree you pull first, you will have conflicts in one of them.  The merge
 resolution has been in linux-next as an example of what to do, or can be
 found here:
 	https://lore.kernel.org/r/CANiq72n3Xe8JcnEjirDhCwQgvWoE65dddWecXnfdnbrmuah-RQ@mail.gmail.com
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updatesk from Greg KH:
 "Here is the big set of driver core updates for 6.15-rc1. Lots of stuff
  happened this development cycle, including:

   - kernfs scaling changes to make it even faster thanks to rcu

   - bin_attribute constify work in many subsystems

   - faux bus minor tweaks for the rust bindings

   - rust binding updates for driver core, pci, and platform busses,
     making more functionaliy available to rust drivers. These are all
     due to people actually trying to use the bindings that were in
     6.14.

   - make Rafael and Danilo full co-maintainers of the driver core
     codebase

   - other minor fixes and updates"

* tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (52 commits)
  rust: platform: require Send for Driver trait implementers
  rust: pci: require Send for Driver trait implementers
  rust: platform: impl Send + Sync for platform::Device
  rust: pci: impl Send + Sync for pci::Device
  rust: platform: fix unrestricted &mut platform::Device
  rust: pci: fix unrestricted &mut pci::Device
  rust: device: implement device context marker
  rust: pci: use to_result() in enable_device_mem()
  MAINTAINERS: driver core: mark Rafael and Danilo as co-maintainers
  rust/kernel/faux: mark Registration methods inline
  driver core: faux: only create the device if probe() succeeds
  rust/faux: Add missing parent argument to Registration::new()
  rust/faux: Drop #[repr(transparent)] from faux::Registration
  rust: io: fix devres test with new io accessor functions
  rust: io: rename `io::Io` accessors
  kernfs: Move dput() outside of the RCU section.
  efi: rci2: mark bin_attribute as __ro_after_init
  rapidio: constify 'struct bin_attribute'
  firmware: qemu_fw_cfg: constify 'struct bin_attribute'
  powerpc/perf/hv-24x7: Constify 'struct bin_attribute'
  ...
2025-04-01 11:02:03 -07:00
Shakeel Butt
7d6c63c319 cgroup: rstat: call cgroup_rstat_updated_list with cgroup_rstat_lock
The commit 093c8812de ("cgroup: rstat: Cleanup flushing functions and
locking") during cleanup accidentally changed the code to call
cgroup_rstat_updated_list() without cgroup_rstat_lock which is required.
Fix it.

Fixes: 093c8812de ("cgroup: rstat: Cleanup flushing functions and locking")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Breno Leitao <leitao@debian.org>
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Closes: https://lore.kernel.org/all/6564c3d6-9372-4352-9847-1eb3aea07ca4@linux.ibm.com/
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-04-01 07:33:26 -10:00
Waiman Long
52e039f9e2 cgroup/cpuset: Remove unneeded goto in sched_partition_write() and rename it
The goto statement in sched_partition_write() is not needed. Remove
it and rename sched_partition_write()/sched_partition_show() to
cpuset_partition_write()/cpuset_partition_show().

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:27:34 -10:00
Waiman Long
f0a0bd3d23 cgroup/cpuset: Code cleanup and comment update
Rename partition_xcpus_newstate() to isolated_cpus_update(),
update_partition_exclusive() to update_partition_exclusive_flag() and
the new_xcpus_state variable to isolcpus_updated to make their meanings
more explicit. Also add some comments to further clarify the code.
No functional change is expected.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:27:19 -10:00
Waiman Long
6da580ec65 cgroup/cpuset: Don't allow creation of local partition over a remote one
Currently, we don't allow the creation of a remote partition underneath
another local or remote partition. However, it is currently possible to
create a new local partition with an existing remote partition underneath
it if top_cpuset is the parent. However, the current cpuset code does
not set the effective exclusive CPUs correctly to account for those
that are taken by the remote partition.

Changing the code to properly account for those remote partition CPUs
under all possible circumstances can be complex. It is much easier to
not allow such a configuration which is not that useful. So forbid
that by making sure that exclusive_cpus mask doesn't overlap with
subpartitions_cpus and invalidate the partition if that happens.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:26:53 -10:00
Waiman Long
f62a5d3936 cgroup/cpuset: Remove remote_partition_check() & make update_cpumasks_hier() handle remote partition
Currently, changes in exclusive CPUs are being handled in
remote_partition_check() by disabling conflicting remote partitions.
However, that may lead to results unexpected by the users. Fix
this problem by removing remote_partition_check() and making
update_cpumasks_hier() handle changes in descendant remote partitions
properly.

The compute_effective_exclusive_cpumask() function is enhanced to check
the exclusive_cpus and effective_xcpus from siblings and excluded them
in its effective exclusive CPUs computation and return a value to show if
there is any sibling conflicts.  This is somewhat like the cpu_exclusive
flag check in validate_change(). This is the initial step to enable us
to retire the use of cpu_exclusive flag in cgroup v2 in the future.

One of the tests in the TEST_MATRIX of the test_cpuset_prs.sh
script has to be updated due to changes in the way a child remote
partition root is being handled (updated instead of invalidation)
in update_cpumasks_hier().

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:25:56 -10:00
Waiman Long
8bf450f3ae cgroup/cpuset: Fix error handling in remote_partition_disable()
When remote_partition_disable() is called to disable a remote partition,
it always sets the partition to an invalid partition state. It should
only do so if an error code (prs_err) has been set. Correct that and
add proper error code in places where remote_partition_disable() is
called due to error.

Fixes: 181c8e091a ("cgroup/cpuset: Introduce remote partition")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:25:38 -10:00
Waiman Long
668e041662 cgroup/cpuset: Fix incorrect isolated_cpus update in update_parent_effective_cpumask()
Before commit f0af1bfc27 ("cgroup/cpuset: Relax constraints to
partition & cpus changes"), a cpuset partition cannot be enabled if not
all the requested CPUs can be granted from the parent cpuset. After
that commit, a cpuset partition can be created even if the requested
exclusive CPUs contain CPUs not allowed its parent.  The delmask
containing exclusive CPUs to be removed from its parent wasn't
adjusted accordingly.

That is not a problem until the introduction of a new isolated_cpus
mask in commit 11e5f407b6 ("cgroup/cpuset: Keep track of CPUs in
isolated partitions") as the CPUs in the delmask may be added directly
into isolated_cpus.

As a result, isolated_cpus may incorrectly contain CPUs that are not
isolated leading to incorrect data reporting. Fix this by adjusting
the delmask to reflect the actual exclusive CPUs for the creation of
the partition.

Fixes: 11e5f407b6 ("cgroup/cpuset: Keep track of CPUs in isolated partitions")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-31 13:25:22 -10:00
Linus Torvalds
32b22538be Scheduler updates for v6.15:
[ Merge note, these two commits are identical:
 
    - f3fa0e40df ("sched/clock: Don't define sched_clock_irqtime as static key")
    - b9f2b29b94 ("sched: Don't define sched_clock_irqtime as static key")
 
   The first one is a cherry-picked version of the second, and the first one
   is already upstream. ]
 
 Core & fair scheduler changes:
 
   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun Dong)
 
 Deadline scheduler: (Juri Lelli)
 
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h
 
 Uclamp:
 
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)
 
 Scheduler topology support: (Juri Lelli)
 
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked
 
 RSEQ: (Michael Jeanson)
 
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes
 
 Membarriers:
 
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)
 
 Scheduler debugging:
 
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)
 
 Fixes and cleanups:
 
   - Always save/restore x86 TSC sched_clock() on suspend/resume
    (Guilherme G. Piccoli)
 
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli,
     Sebastian Andrzej Siewior)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core & fair scheduler changes:

   - Cancel the slice protection of the idle entity (Zihan Zhou)
   - Reduce the default slice to avoid tasks getting an extra tick
     (Zihan Zhou)
   - Force propagating min_slice of cfs_rq when {en,de}queue tasks
     (Tianchen Ding)
   - Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
   - Add unlikey branch hints to several system calls (Colin Ian King)
   - Optimize current_clr_polling() on certain architectures (Yujun
     Dong)

  Deadline scheduler: (Juri Lelli)
   - Remove redundant dl_clear_root_domain call
   - Move dl_rebuild_rd_accounting to cpuset.h

  Uclamp:
   - Use the uclamp_is_used() helper instead of open-coding it (Xuewen
     Yan)
   - Optimize sched_uclamp_used static key enabling (Xuewen Yan)

  Scheduler topology support: (Juri Lelli)
   - Ignore special tasks when rebuilding domains
   - Add wrappers for sched_domains_mutex
   - Generalize unique visiting of root domains
   - Rebuild root domain accounting after every update
   - Remove partition_and_rebuild_sched_domains
   - Stop exposing partition_sched_domains_locked

  RSEQ: (Michael Jeanson)
   - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
   - Fix segfault on registration when rseq_cs is non-zero
   - selftests: Add rseq syscall errors test
   - selftests: Ensure the rseq ABI TLS is actually 1024 bytes

  Membarriers:
   - Fix redundant load of membarrier_state (Nysal Jan K.A.)

  Scheduler debugging:
   - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
   - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)

  Fixes and cleanups:
   - Always save/restore x86 TSC sched_clock() on suspend/resume
     (Guilherme G. Piccoli)
   - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
     Andrzej Siewior)"

* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
  sched/debug: Remove CONFIG_SCHED_DEBUG
  sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
  sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
  sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
  sched/debug: Make 'const_debug' tunables unconditional __read_mostly
  sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
  rseq/selftests: Fix namespace collision with rseq UAPI header
  include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
  sched/topology: Stop exposing partition_sched_domains_locked
  cgroup/cpuset: Remove partition_and_rebuild_sched_domains
  sched/topology: Remove redundant dl_clear_root_domain call
  sched/deadline: Rebuild root domain accounting after every update
  sched/deadline: Generalize unique visiting of root domains
  sched/topology: Wrappers for sched_domains_mutex
  sched/deadline: Ignore special tasks when rebuilding domains
  tracing: Use preempt_model_str()
  xtensa: Rely on generic printing of preemption model
  x86: Rely on generic printing of preemption model
  s390: Rely on generic printing of preemption model
  ...
2025-03-24 21:28:12 -07:00
Linus Torvalds
94dc216ad8 cgroup: Changes for v6.15
- Add deprecation info messages to cgroup1-only features.
 
 - rstat updates including a bug fix and breaking up a critical section to
   reduce interrupt latency impact.
 
 - Other misc and doc updates.
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Merge tag 'cgroup-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - Add deprecation info messages to cgroup1-only features

 - rstat updates including a bug fix and breaking up a critical section
   to reduce interrupt latency impact

 - Other misc and doc updates

* tag 'cgroup-for-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: rstat: Cleanup flushing functions and locking
  cgroup/rstat: avoid disabling irqs for O(num_cpu)
  mm: Fix a build breakage in memcontrol-v1.c
  blk-cgroup: Simplify policy files registration
  cgroup: Update file naming comment
  cgroup: Add deprecation message to legacy freezer controller
  mm: Add transformation message for per-memcg swappiness
  RFC cgroup/cpuset-v1: Add deprecation messages to sched_relax_domain_level
  cgroup/cpuset-v1: Add deprecation messages to memory_migrate
  cgroup/cpuset-v1: Add deprecation messages to mem_exclusive and mem_hardwall
  cgroup: Print message when /proc/cgroups is read on v2-only system
  cgroup/blkio: Add deprecation messages to reset_stats
  cgroup/cpuset-v1: Add deprecation messages to memory_spread_page and memory_spread_slab
  cgroup/cpuset-v1: Add deprecation messages to sched_load_balance and memory_pressure_enabled
  cgroup, docs: Be explicit about independence of RT_GROUP_SCHED and non-cpu controllers
  cgroup/rstat: Fix forceidle time in cpu.stat
  cgroup/misc: Remove unused misc_cg_res_total_usage
  cgroup/cpuset: Move procfs cpuset attribute under cgroup-v1.c
  cgroup: update comment about dropping cgroup kn refs
2025-03-24 16:49:40 -07:00
Yosry Ahmed
093c8812de cgroup: rstat: Cleanup flushing functions and locking
Now that the rstat lock is being re-acquired on every CPU iteration in
cgroup_rstat_flush_locked(), having the initially acquire the lock is
unnecessary and unclear.

Inline cgroup_rstat_flush_locked() into cgroup_rstat_flush() and move
the lock/unlock calls to the beginning and ending of the loop body to
make the critical section obvious.

cgroup_rstat_flush_hold/release() do not make much sense with the lock
being dropped and reacquired internally. Since it has no external
callers, remove it and explicitly acquire the lock in
cgroup_base_stat_cputime_show() instead.

This leaves the code with a single flushing function,
cgroup_rstat_flush().

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-20 06:53:02 -10:00
Eric Dumazet
0efc297a3c cgroup/rstat: avoid disabling irqs for O(num_cpu)
cgroup_rstat_flush_locked() grabs the irq safe cgroup_rstat_lock while
iterating all possible cpus. It only drops the lock if there is
scheduler or spin lock contention. If neither, then interrupts can be
disabled for a long time. On large machines this can disable interrupts
for a long enough time to drop network packets. On 400+ CPU machines
I've seen interrupt disabled for over 40 msec.

Prevent rstat from disabling interrupts while processing all possible
cpus. Instead drop and reacquire cgroup_rstat_lock for each cpu. This
approach was previously discussed in
https://lore.kernel.org/lkml/ZBz%2FV5a7%2F6PZeM7S@slm.duckdns.org/,
though this was in the context of an non-irq rstat spin lock.

Benchmark this change with:
1) a single stat_reader process with 400 threads, each reading a test
   memcg's memory.stat repeatedly for 10 seconds.
2) 400 memory hog processes running in the test memcg and repeatedly
   charging memory until oom killed. Then they repeat charging and oom
   killing.

v6.14-rc6 with CONFIG_IRQSOFF_TRACER with stat_reader and hogs, finds
interrupts are disabled by rstat for 45341 usec:
  #  => started at: _raw_spin_lock_irq
  #  => ended at:   cgroup_rstat_flush
  #
  #
  #                    _------=> CPU#
  #                   / _-----=> irqs-off/BH-disabled
  #                  | / _----=> need-resched
  #                  || / _---=> hardirq/softirq
  #                  ||| / _--=> preempt-depth
  #                  |||| / _-=> migrate-disable
  #                  ||||| /     delay
  #  cmd     pid     |||||| time  |   caller
  #     \   /        ||||||  \    |    /
  stat_rea-96532    52d....    0us*: _raw_spin_lock_irq
  stat_rea-96532    52d.... 45342us : cgroup_rstat_flush
  stat_rea-96532    52d.... 45342us : tracer_hardirqs_on <-cgroup_rstat_flush
  stat_rea-96532    52d.... 45343us : <stack trace>
   => memcg1_stat_format
   => memory_stat_format
   => memory_stat_show
   => seq_read_iter
   => vfs_read
   => ksys_read
   => do_syscall_64
   => entry_SYSCALL_64_after_hwframe

With this patch the CONFIG_IRQSOFF_TRACER doesn't find rstat to be the
longest holder. The longest irqs-off holder has irqs disabled for
4142 usec, a huge reduction from previous 45341 usec rstat finding.

Running stat_reader memory.stat reader for 10 seconds:
- without memory hogs: 9.84M accesses => 12.7M accesses
-    with memory hogs: 9.46M accesses => 11.1M accesses
The throughput of memory.stat access improves.

The mode of memory.stat access latency after grouping by of 2 buckets:
- without memory hogs: 64 usec => 16 usec
-    with memory hogs: 64 usec =>  8 usec
The memory.stat latency improves.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Greg Thelen <gthelen@google.com>
Tested-by: Greg Thelen <gthelen@google.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-19 07:25:00 -10:00
Juri Lelli
ce9b3f93d7 cgroup/cpuset: Remove partition_and_rebuild_sched_domains
partition_and_rebuild_sched_domains() and partition_sched_domains() are
now equivalent.

Remove the former as a nice clean up.

Suggested-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <llong@redhat.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Waiman Long <longman@redhat.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MR4ryNDJZDzsSG@jlelli-thinkpadt14gen4.remote.csb
2025-03-17 11:23:42 +01:00
Juri Lelli
2ff899e351 sched/deadline: Rebuild root domain accounting after every update
Rebuilding of root domains accounting information (total_bw) is
currently broken on some cases, e.g. suspend/resume on aarch64. Problem
is that the way we keep track of domain changes and try to add bandwidth
back is convoluted and fragile.

Fix it by simplify things by making sure bandwidth accounting is cleared
and completely restored after root domains changes (after root domains
are again stable).

To be sure we always call dl_rebuild_rd_accounting while holding
cpuset_mutex we also add cpuset_reset_sched_domains() wrapper.

Fixes: 53916d5fd3 ("sched/deadline: Check bandwidth overflow earlier for hotplug")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Co-developed-by: Waiman Long <llong@redhat.com>
Signed-off-by: Waiman Long <llong@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MRfeJKJUOyUSto@jlelli-thinkpadt14gen4.remote.csb
2025-03-17 11:23:42 +01:00
Juri Lelli
56209334dd sched/topology: Wrappers for sched_domains_mutex
Create wrappers for sched_domains_mutex so that it can transparently be
used on both CONFIG_SMP and !CONFIG_SMP, as some function will need to
do.

Fixes: 53916d5fd3 ("sched/deadline: Check bandwidth overflow earlier for hotplug")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Waiman Long <longman@redhat.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/Z9MP5Oq9RB8jBs3y@jlelli-thinkpadt14gen4.remote.csb
2025-03-17 11:23:41 +01:00
Zhiming Hu
7c035bea94 KVM: TDX: Register TDX host key IDs to cgroup misc controller
TDX host key IDs (HKID) are limit resources in a machine, and the misc
cgroup lets the machine owner track their usage and limits the possibility
of abusing them outside the owner's control.

The cgroup v2 miscellaneous subsystem was introduced to control the
resource of AMD SEV & SEV-ES ASIDs.  Likewise introduce HKIDs as a misc
resource.

Signed-off-by: Zhiming Hu <zhiming.hu@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-03-14 14:20:51 -04:00
Michal Koutný
4a893bdc18 blk-cgroup: Simplify policy files registration
Use one set of files when there is no difference between default and
legacy files, similar to regular subsys files registration. No
functional change.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:55 -10:00
Michal Koutný
78f6519ed0 cgroup: Add deprecation message to legacy freezer controller
As explained in the commit 76f969e894 ("cgroup: cgroup v2 freezer"),
the original freezer is imperfect, some users may unwittingly rely on it
when there exists the alternative of v2. Print a message when it happens
and explain that in the docs.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
103149a063 RFC cgroup/cpuset-v1: Add deprecation messages to sched_relax_domain_level
This is not a properly hierarchical resource, it might be better
implemented based on a sched_attr.

Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
db4dc20c11 cgroup/cpuset-v1: Add deprecation messages to memory_migrate
Memory migration (between cgroups) was given up in v2 due to performance
reasons of its implementation. Migration between NUMA nodes within one
memcg may still make sense to modify affinity at runtime though.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
3138192792 cgroup/cpuset-v1: Add deprecation messages to mem_exclusive and mem_hardwall
The concept of exclusive memory affinity may require complex approaches
like with cpuset v2 cpu partitions. There is so far no implementation in
cpuset v2.
Specific kernel memory affinity may cause unintended (global)
bottlenecks like kmem limits.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
a0ab145322 cgroup: Print message when /proc/cgroups is read on v2-only system
As a followup to commits 6c2920926b ("cgroup: replace
unified-hierarchy.txt with a proper cgroup v2 documentation") and
ab03125268 ("cgroup: Show # of subsystem CSSes in cgroup.stat"),
add a runtime message to users who read status of controllers in
/proc/cgroups on v2-only system. The detection is based on a)
no controllers are attached to v1, b) default hierarchy is mounted (the
latter is for setups that never mount v2 but read /proc/cgroups upon
boot when controllers default to v2, so that this code may be backported
to older kernels).

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
012c419f8d cgroup/cpuset-v1: Add deprecation messages to memory_spread_page and memory_spread_slab
There is MPOL_INTERLEAVE for user explicit allocations.
Deprecate spreading of allocations that users carry out unwittingly.
Use straight warning level for slab spreading since such a knob is
unnecessarily intertwined with slab allocator.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Michal Koutný
a0dd846257 cgroup/cpuset-v1: Add deprecation messages to sched_load_balance and memory_pressure_enabled
These two v1 feature have analogues in cgroup v2.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-11 09:22:54 -10:00
Greg Kroah-Hartman
993a47bd7b Linux 6.14-rc6
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Merge 6.14-rc6 into driver-core-next

We need the driver core fix in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-10 17:37:25 +01:00
Abel Wu
c4af66a95a cgroup/rstat: Fix forceidle time in cpu.stat
The commit b824766504 ("cgroup/rstat: add force idle show helper")
retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups
which can be potentially inconsistent with other stats.

Rather than reverting that commit, fix it in a way that retains the
effort of cleaning up the ifdef-messes.

Fixes: b824766504 ("cgroup/rstat: add force idle show helper")
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-02-27 07:19:17 -10:00
Dave Airlie
395436f3bd An reset signal polarity fix for the jd9365da-h3 panel, a folio handling
fix and config fix in nouveau, a dmem cgroup descendant pool handling
 fix, and a missing header for amdxdna.
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Merge tag 'drm-misc-fixes-2025-02-20' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes

An reset signal polarity fix for the jd9365da-h3 panel, a folio handling
fix and config fix in nouveau, a dmem cgroup descendant pool handling
fix, and a missing header for amdxdna.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250220-glorious-cockle-of-might-5b35f7@houat
2025-02-21 09:16:35 +10:00
Friedrich Vock
8821f36333 cgroup/dmem: Don't open-code css_for_each_descendant_pre
The current implementation has a bug: If the current css doesn't
contain any pool that is a descendant of the "pool" (i.e. when
found_descendant == false), then "pool" will point to some unrelated
pool. If the current css has a child, we'll overwrite parent_pool with
this unrelated pool on the next iteration.

Since we can just check whether a pool refers to the same region to
determine whether or not it's related, all the additional pool tracking
is unnecessary, so just switch to using css_for_each_descendant_pre for
traversal.

Fixes: b168ed458d ("kernel/cgroup: Add "dmem" memory accounting cgroup")
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250127152754.21325-1-friedrich.vock@gmx.de
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
2025-02-19 09:50:37 +01:00
Greg Kroah-Hartman
2ce177e9b3 Merge 6.14-rc3 into driver-core-next
We need the faux_device changes in here for future work.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17 07:24:33 +01:00
Sebastian Andrzej Siewior
633488947e kernfs: Use RCU to access kernfs_node::parent.
kernfs_rename_lock is used to obtain stable kernfs_node::{name|parent}
pointer. This is a preparation to access kernfs_node::parent under RCU
and ensure that the pointer remains stable under the RCU lifetime
guarantees.

For a complete path, as it is done in kernfs_path_from_node(), the
kernfs_rename_lock is still required in order to obtain a stable parent
relationship while computing the relevant node depth. This must not
change while the nodes are inspected in order to build the path.
If the kernfs user never moves the nodes (changes the parent) then the
kernfs_rename_lock is not required and the RCU guarantees are
sufficient. This "restriction" can be set with
KERNFS_ROOT_INVARIANT_PARENT. Otherwise the lock is required.

Rename kernfs_node::parent to kernfs_node::__parent to denote the RCU
access and use RCU accessor while accessing the node.
Make cgroup use KERNFS_ROOT_INVARIANT_PARENT since the parent here can
not change.

Acked-by: Tejun Heo <tj@kernel.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20250213145023.2820193-6-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-15 17:46:32 +01:00
Muhammad Adeel
db5fd3cf8b cgroup: Remove steal time from usage_usec
The CPU usage time is the time when user, system or both are using the CPU.
Steal time is the time when CPU is waiting to be run by the Hypervisor. It
should not be added to the CPU usage time, hence removing it from the
usage_usec entry.

Fixes: 936f2a70f2 ("cgroup: add cpu.stat file to root cgroup")
Acked-by: Axel Busch <axel.busch@ibm.com>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Muhammad Adeel <muhammad.adeel@ibm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-02-07 11:02:17 -10:00
Shakeel Butt
b69bb476de cgroup: fix race between fork and cgroup.kill
Tejun reported the following race between fork() and cgroup.kill at [1].

Tejun:
  I was looking at cgroup.kill implementation and wondering whether there
  could be a race window. So, __cgroup_kill() does the following:

   k1. Set CGRP_KILL.
   k2. Iterate tasks and deliver SIGKILL.
   k3. Clear CGRP_KILL.

  The copy_process() does the following:

   c1. Copy a bunch of stuff.
   c2. Grab siglock.
   c3. Check fatal_signal_pending().
   c4. Commit to forking.
   c5. Release siglock.
   c6. Call cgroup_post_fork() which puts the task on the css_set and tests
       CGRP_KILL.

  The intention seems to be that either a forking task gets SIGKILL and
  terminates on c3 or it sees CGRP_KILL on c6 and kills the child. However, I
  don't see what guarantees that k3 can't happen before c6. ie. After a
  forking task passes c5, k2 can take place and then before the forking task
  reaches c6, k3 can happen. Then, nobody would send SIGKILL to the child.
  What am I missing?

This is indeed a race. One way to fix this race is by taking
cgroup_threadgroup_rwsem in write mode in __cgroup_kill() as the fork()
side takes cgroup_threadgroup_rwsem in read mode from cgroup_can_fork()
to cgroup_post_fork(). However that would be heavy handed as this adds
one more potential stall scenario for cgroup.kill which is usually
called under extreme situation like memory pressure.

To fix this race, let's maintain a sequence number per cgroup which gets
incremented on __cgroup_kill() call. On the fork() side, the
cgroup_can_fork() will cache the sequence number locally and recheck it
against the cgroup's sequence number at cgroup_post_fork() site. If the
sequence numbers mismatch, it means __cgroup_kill() can been called and
we should send SIGKILL to the newly created task.

Reported-by: Tejun Heo <tj@kernel.org>
Closes: https://lore.kernel.org/all/Z5QHE2Qn-QZ6M-KW@slm.duckdns.org/ [1]
Fixes: 661ee62809 ("cgroup: introduce cgroup.kill")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-02-02 06:54:51 -10:00
Dr. David Alan Gilbert
ad6c08d8c1 cgroup/misc: Remove unused misc_cg_res_total_usage
misc_cg_res_total_usage() was added in 2021 by
commit a72232eabd ("cgroup: Add misc cgroup controller")

but has remained unused.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-01-28 09:00:54 -10:00
Michal Koutný
dae68fba8e cgroup/cpuset: Move procfs cpuset attribute under cgroup-v1.c
The cpuset file is a legacy attribute that is bound primarily to cpuset
v1 hierarchy (equivalent information is available in /proc/$pid/cgroup path
on the unified hierarchy in conjunction with respective
cgroup.controllers showing where cpuset controller is enabled).

Followup to commit b0ced9d378 ("cgroup/cpuset: move v1 interfaces to
cpuset-v1.c") and hide CONFIG_PROC_PID_CPUSET under CONFIG_CPUSETS_V1.
Drop an obsolete comment too.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-01-24 12:01:41 -10:00
Simona Vetter
07c5b27720 Linux 6.13
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Merge v6.13 into drm-next

A regression was caused by commit e4b5ccd392 ("drm/v3d: Ensure job
pointer is set to NULL after job completion"), but this commit is not
yet in next-fixes, fast-forward it.

Note that this recreates Linus merge in 96c84703f1 ("Merge tag
'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel")
because I didn't want to backmerge a random point in the merge window.

Signed-off-by: Simona Vetter <simona.vetter@ffwll.ch>
2025-01-23 14:42:21 +01:00
Linus Torvalds
96c84703f1 drm next for 6.14-rc1
core:
 - device memory cgroup controller added
 - Remove driver date from drm_driver
 - Add drm_printer based hex dumper
 - drm memory stats docs update
 - scheduler documentation improvements
 
 new driver:
 - amdxdna - Ryzen AI NPU support
 
 connector:
 - add a mutex to protect ELD
 - make connector setup two-step
 
 panels:
 - Introduce backlight quirks infrastructure
 - New panels: KDB KD116N2130B12, Tianma TM070JDHG34-00,
 - Multi-Inno Technology MI1010Z1T-1CP11
 
 bridge:
 - ti-sn65dsi83: Add ti,lvds-vod-swing optional properties
 - Provide default implementation of atomic_check for HDMI bridges
 - it605: HDCP improvements, MCCS Support
 
 xe:
 - make OA buffer size configurable
 - GuC capture fixes
 - add ufence and g2h flushes
 - restore system memory GGTT mappings
 - ioctl fixes
 - SRIOV PF scheduling priority
 - allow fault injection
 - lots of improvements/refactors
 - Enable GuC's WA_DUAL_QUEUE for newer platforms
 - IRQ related fixes and improvements
 
 i915:
 - More accurate engine busyness metrics with GuC submission
 - Ensure partial BO segment offset never exceeds allowed max
 - Flush GuC CT receive tasklet during reset preparation
 - Some DG2 refactor to fix DG2 bugs when operating with certain CPUs
 - Fix DG1 power gate sequence
 - Enabling uncompressed 128b/132b UHBR SST
 - Handle hdmi connector init failures, and no HDMI/DP cases
 - More robust engine resets on Haswell and older
 
 i915/xe display:
 - HDCP fixes for Xe3Lpd
 - New GSC FW ARL-H/ARL-U
 - support 3 VDSC engines 12 slices
 - MBUS joining sanitisation
 - reconcile i915/xe display power mgmt
 - Xe3Lpd fixes
 - UHBR rates for Thunderbolt
 
 amdgpu:
 - DRM panic support
 - track BO memory stats at runtime
 - Fix max surface handling in DC
 - Cleaner shader support for gfx10.3 dGPUs
 - fix drm buddy trim handling
 - SDMA engine reset updates
 - Fix doorbell ttm cleanup
 - RAS updates
 - ISP updates
 - SDMA queue reset support
 - Rework DPM powergating interfaces
 - Documentation updates and cleanups
 - DCN 3.5 updates
 - Use a pm notifier to more gracefully handle VRAM eviction on suspend or hibernate
 - Add debugfs interfaces for forcing scheduling to specific engine instances
 - GG 9.5 updates
 - IH 4.4 updates
 - Make missing optional firmware less noisy
 - PSP 13.x updates
 - SMU 13.x updates
 - VCN 5.x updates
 - JPEG 5.x updates
 - GC 12.x updates
 - DC FAMS updates
 
 amdkfd:
 - GG 9.5 updates
 - Logging improvements
 - Shader debugger fixes
 - Trap handler cleanup
 - Cleanup includes
 - Eviction fence wq fix
 
 msm:
 - MDSS:
 - properly described UBWC registers
 - added SM6150 (aka QCS615) support
 - DPU:
 - added SM6150 (aka QCS615) support
 - enabled wide planes if virtual planes are enabled (by using two SSPPs for a single plane)
 - added CWB hardware blocks support
 - DSI:
 - added SM6150 (aka QCS615) support
 - GPU:
 - Print GMU core fw version
 - GMU bandwidth voting for a740 and a750
 - Expose uche trap base via uapi
 - UAPI error reporting
 
 rcar-du:
 - Add r8a779h0 Support
 
 ivpu:
 - Fix qemu crash when using passthrough
 
 nouveau:
 - expose GSP-RM logging buffers via debugfs
 
 panfrost:
 - Add MT8188 Mali-G57 MC3 support
 
 rockchip:
 - Gamma LUT support
 
 hisilicon:
 - new HIBMC support
 
 virtio-gpu:
 - convert to helpers
 - add prime support for scanout buffers
 
 v3d:
 - Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL
 
 vc4:
 - Add support for BCM2712
 
 vkms:
 - line-per-line compositing algorithm to improve performance
 
 zynqmp:
 - Add DP audio support
 
 mediatek:
 - dp: Add sdp path reset
 - dp: Support flexible length of DP calibration data
 
 etnaviv:
 - add fdinfo memory support
 - add explicit reset handling
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Merge tag 'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel

Pull drm updates from Dave Airlie:
 "There are two external interactions of note, the msm tree pull in some
  opp tree, hopefully the opp tree arrives from the same git tree
  however it normally does.

  There is also a new cgroup controller for device memory, that is used
  by drm, so is merging through my tree. This will hopefully help open
  up gpu cgroup usage a bit more and move us forward.

  There is a new accelerator driver for the AMD XDNA Ryzen AI NPUs.

  Then the usual xe/amdgpu/i915/msm leaders and lots of changes and
  refactors across the board:

  core:
   - device memory cgroup controller added
   - Remove driver date from drm_driver
   - Add drm_printer based hex dumper
   - drm memory stats docs update
   - scheduler documentation improvements

  new driver:
   - amdxdna - Ryzen AI NPU support

  connector:
   - add a mutex to protect ELD
   - make connector setup two-step

  panels:
   - Introduce backlight quirks infrastructure
   - New panels: KDB KD116N2130B12, Tianma TM070JDHG34-00,
   - Multi-Inno Technology MI1010Z1T-1CP11

  bridge:
   - ti-sn65dsi83: Add ti,lvds-vod-swing optional properties
   - Provide default implementation of atomic_check for HDMI bridges
   - it605: HDCP improvements, MCCS Support

  xe:
   - make OA buffer size configurable
   - GuC capture fixes
   - add ufence and g2h flushes
   - restore system memory GGTT mappings
   - ioctl fixes
   - SRIOV PF scheduling priority
   - allow fault injection
   - lots of improvements/refactors
   - Enable GuC's WA_DUAL_QUEUE for newer platforms
   - IRQ related fixes and improvements

  i915:
   - More accurate engine busyness metrics with GuC submission
   - Ensure partial BO segment offset never exceeds allowed max
   - Flush GuC CT receive tasklet during reset preparation
   - Some DG2 refactor to fix DG2 bugs when operating with certain CPUs
   - Fix DG1 power gate sequence
   - Enabling uncompressed 128b/132b UHBR SST
   - Handle hdmi connector init failures, and no HDMI/DP cases
   - More robust engine resets on Haswell and older

  i915/xe display:
   - HDCP fixes for Xe3Lpd
   - New GSC FW ARL-H/ARL-U
   - support 3 VDSC engines 12 slices
   - MBUS joining sanitisation
   - reconcile i915/xe display power mgmt
   - Xe3Lpd fixes
   - UHBR rates for Thunderbolt

  amdgpu:
   - DRM panic support
   - track BO memory stats at runtime
   - Fix max surface handling in DC
   - Cleaner shader support for gfx10.3 dGPUs
   - fix drm buddy trim handling
   - SDMA engine reset updates
   - Fix doorbell ttm cleanup
   - RAS updates
   - ISP updates
   - SDMA queue reset support
   - Rework DPM powergating interfaces
   - Documentation updates and cleanups
   - DCN 3.5 updates
   - Use a pm notifier to more gracefully handle VRAM eviction on
     suspend or hibernate
   - Add debugfs interfaces for forcing scheduling to specific engine
     instances
   - GG 9.5 updates
   - IH 4.4 updates
   - Make missing optional firmware less noisy
   - PSP 13.x updates
   - SMU 13.x updates
   - VCN 5.x updates
   - JPEG 5.x updates
   - GC 12.x updates
   - DC FAMS updates

  amdkfd:
   - GG 9.5 updates
   - Logging improvements
   - Shader debugger fixes
   - Trap handler cleanup
   - Cleanup includes
   - Eviction fence wq fix

  msm:
   - MDSS:
      - properly described UBWC registers
      - added SM6150 (aka QCS615) support
   - DPU:
      - added SM6150 (aka QCS615) support
      - enabled wide planes if virtual planes are enabled (by using two
        SSPPs for a single plane)
      - added CWB hardware blocks support
   - DSI:
      - added SM6150 (aka QCS615) support
   - GPU:
      - Print GMU core fw version
      - GMU bandwidth voting for a740 and a750
      - Expose uche trap base via uapi
      - UAPI error reporting

  rcar-du:
   - Add r8a779h0 Support

  ivpu:
   - Fix qemu crash when using passthrough

  nouveau:
   - expose GSP-RM logging buffers via debugfs

  panfrost:
   - Add MT8188 Mali-G57 MC3 support

  rockchip:
   - Gamma LUT support

  hisilicon:
   - new HIBMC support

  virtio-gpu:
   - convert to helpers
   - add prime support for scanout buffers

  v3d:
   - Add DRM_IOCTL_V3D_PERFMON_SET_GLOBAL

  vc4:
   - Add support for BCM2712

  vkms:
   - line-per-line compositing algorithm to improve performance

  zynqmp:
   - Add DP audio support

  mediatek:
   - dp: Add sdp path reset
   - dp: Support flexible length of DP calibration data

  etnaviv:
   - add fdinfo memory support
   - add explicit reset handling"

* tag 'drm-next-2025-01-17' of https://gitlab.freedesktop.org/drm/kernel: (1070 commits)
  drm/bridge: fix documentation for the hdmi_audio_prepare() callback
  doc/cgroup: Fix title underline length
  drm/doc: Include new drm-compute documentation
  cgroup/dmem: Fix parameters documentation
  cgroup/dmem: Select PAGE_COUNTER
  kernel/cgroup: Remove the unused variable climit
  drm/display: hdmi: Do not read EDID on disconnected connectors
  drm/tests: hdmi: Add connector disablement test
  drm/connector: hdmi: Do atomic check when necessary
  drm/amd/display: 3.2.316
  drm/amd/display: avoid reset DTBCLK at clock init
  drm/amd/display: improve dpia pre-train
  drm/amd/display: Apply DML21 Patches
  drm/amd/display: Use HW lock mgr for PSR1
  drm/amd/display: Revised for Replay Pseudo vblank control
  drm/amd/display: Add a new flag for replay low hz
  drm/amd/display: Remove unused read_ono_state function from Hwss module
  drm/amd/display: Do not elevate mem_type change to full update
  drm/amd/display: Do not wait for PSR disable on vbl enable
  drm/amd/display: Remove unnecessary eDP power down
  ...
2025-01-21 16:09:47 -08:00
Haorui He
4a6780a30e cgroup: update comment about dropping cgroup kn refs
the cgroup is actually freed in css_free_rwork_fn() now
the ref count of the cgroup's kernfs_node is also dropped there
so we need to update the corresponding comment in cgroup_mkdir()

Signed-off-by: Haorui He <mail@hehaorui.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-01-21 09:24:47 -10:00