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26743 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
b95f03f04d |
12 hotfixes. 8 are cc:stable and the remainder address post-7.1 issues or
aren't considered appropriate for backporting. 10 are for MM. All are singletons - please see the relevant changelogs for details. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCal5rBQAKCRDdBJ7gKXxA jtgtAQCuWNUTCR7u+MzAuO3Nh46DxHXeb27OTHZL8JcazQTEQgD+NZfwqVYnNNX/ 4CVqqZvrXJQDg0aiWtIP4VdLirNh/Ac= =Gslp -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2026-07-20-11-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "12 hotfixes. 8 are cc:stable and the remainder address post-7.1 issues or aren't considered appropriate for backporting. 10 are for MM. All are singletons - please see the relevant changelogs for details" * tag 'mm-hotfixes-stable-2026-07-20-11-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/memory-failure: trace: change memory_failure_event to ras subsystem mm: page_reporting: allow driver to set batch capacity mm/kmemleak: fix checksum computation for per-cpu objects mm/damon/core: disallow overlapping input ranges for damon_set_regions() MAINTAINERS: add Usama as a THP reviewer fat: avoid stack overflow warning mm/damon/core: validate ranges in damon_set_regions() m68k: avoid -Wunused-but-set-parameter in clear_user_page() mm/huge_memory: set PG_has_hwpoisoned only after new folio head is established mm/page_vma_mapped: fix device-private PMD handling MAINTAINERS: s/SeongJae/SJ/ userfaultfd: prevent registration of special VMAs |
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Vivian Wang
|
4edd70ee6a |
mm/sparse-vmemmap: flush_cache_vmap() after hotplugging vmemmap
section_activate() does not flush TLB after populating new vmemmap pages. On most architectures, this is okay. However it is a problem on RISC-V since there the TLB caching non-present entries is permitted, which causes spurious faults on some hardwares. This seems to be most easily reproduced with DEBUG_VM=y and PAGE_POISONING=y, which causes these newly mapped struct pages to be poisoned i.e. written to immediately after mapping. Extend the RISC-V flush_cache_vmap() to also handle the vmemmap range, and call it after hotplugging vmemmap, which gets the possible spurious fault handled in the exception handler. At least for now, the only other architecture with both SPARSEMEM_VMEMMAP and flush_cache_vmap() is PowerPC, which has a similar problem with newly valid PTEs. But there flush_cache_vmap() is just a ptesync. So it should be safe to do this for generic code while having minimal performance impact. Suggested-by: Muchun Song <muchun.song@linux.dev> Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn> Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Link: https://patch.msgid.link/20260713-mark-after-vmemmap-populate-v6-2-b945ceba29d4@iscas.ac.cn Signed-off-by: Paul Walmsley <pjw@kernel.org> |
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Michael S. Tsirkin
|
47c81dadb7 |
mm: page_reporting: allow driver to set batch capacity
At the moment, if a virtio balloon device has a page reporting vq but its
size is < PAGE_REPORTING_CAPACITY (32), the balloon driver fails probe.
But, there's no way for host to know this value, so it can easily create a
smaller vq and suddenly adding the reporting capability to the device
makes all of the driver fail. Not pretty.
Add a capacity field to page_reporting_dev_info so drivers can control the
maximum number of pages per report batch.
In virtio-balloon, set the capacity to the reporting virtqueue size,
letting page_reporting adapt to whatever the device provides.
Capacity need not be a power of two. Code previously called out division
by PAGE_REPORTING_CAPACITY as cheap since it was a power of 2, but no
performance difference was observed with non-power-of-2 values.
If capacity is 0 or exceeds PAGE_REPORTING_CAPACITY, it defaults to
PAGE_REPORTING_CAPACITY. The 0 check and the clamping is done in
page_reporting_register(), before the reporting work is scheduled, so we
never get division by 0.
Link: https://lore.kernel.org/444c24cf39f3f3620fc90ef4695bd6b0979f4c4b.1783232420.git.mst@redhat.com
Fixes:
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Breno Leitao
|
79c37ae373 |
mm/kmemleak: fix checksum computation for per-cpu objects
The per-cpu object checksum folds each CPU's CRC together with XOR and
seeds every CRC with 0. Both choices make update_checksum() miss content
changes:
- XOR is self-cancelling, so equal contents on two CPUs cancel out and
simultaneous identical changes leave the checksum unchanged.
- crc32(0, ...) over all-zero content is 0, so a freshly allocated,
zeroed per-cpu area checksums to 0, matching the initial value, and
the object is never seen to change.
See discussions at [0].
When update_checksum() wrongly reports an actively modified object as
unchanged, kmemleak stops greying it for an extra scan and can report a
live per-cpu object as a leak.
Fold the per-cpu CRC as a single rolling checksum across all CPUs and
initialise the object checksum to ~0 so the first computed value always
registers as a change, even for content that hashes to 0.
reset_checksum() is seeded the same way.
Link: https://lore.kernel.org/all/akfYImSNDh3OjIfR@gmail.com [0]
Link: https://lore.kernel.org/20260703-kmemleak_checksum-v1-1-5e0ab7d6966f@debian.org
Fixes:
|
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SJ Park
|
954157679e |
mm/damon/core: disallow overlapping input ranges for damon_set_regions()
damon_set_regions() assumes the input ranges are sorted by the address and don't overlap each other. Hence the assumption was initially to be explicitly validated. But commit |
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SJ Park
|
1292c0ecb1 |
mm/damon/core: validate ranges in damon_set_regions()
DAMON core logic assumes zero length regions don't exist. However, a few
DAMON API callers including DAMON_SYSFS, DAMON_RECLAIM and DAMON_LRU_SORT
allow users to set empty monitoring target regions. This could result in
WARN_ONCE() on CONFIG_DAMON_DEBUG_SANITY enabled kernel, and
divide-by-zero from damon_merge_two_regions().
For example, the WANR_ONCE() can be triggered like below.
# grep DAMON_DEBUG_SANITY /boot/config-$(uname -r)
# CONFIG_DAMON_DEBUG_SANITY=y
# damo start
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/0/targets/0/regions/0/start
# echo 0 > contexts/0/targets/0/regions/0/end
# echo commit > state
# dmesg
[....]
[ 73.705780] ------------[ cut here ]------------
[ 73.707552] start 0 >= end 0
[ 73.708452] WARNING: mm/damon/core.c:359 at damon_new_region+0x6e/0x80, CPU#1: kdamond.0/758
[...]
All DAMON API callers eventually use damon_set_regions() to setup the
regions. Add the validation logic in the function.
Link: https://lore.kernel.org/20260630035221.146458-1-sj@kernel.org
Fixes:
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Rik van Riel
|
e1cd30eceb |
mm/huge_memory: set PG_has_hwpoisoned only after new folio head is established
__split_folio_to_order() copies the hwpoison state onto each new sub-folio while splitting a folio to a non-zero order. It does so via if (handle_hwpoison && page_range_has_hwpoisoned(new_head, new_nr_pages)) folio_set_has_hwpoisoned(new_folio); *before* clear_compound_head(new_head)/prep_compound_page(new_head, ...) turns @new_head from a tail page into a proper folio head. PG_has_hwpoisoned is a FOLIO_SECOND_PAGE flag, so folio_set_has_hwpoisoned() resolves to folio_flags(folio, 1). With the new compound_info-based page-flags layout, folio_flags() asserts the page is not a tail: VM_BUG_ON_PGFLAGS(page->compound_info & 1, page); VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page); At the current call site @new_head still has the tail marker (compound_info bit 0 set, PG_head clear), so on CONFIG_DEBUG_VM kernels this hits: kernel BUG at include/linux/page-flags.h:354 folio_flags+0x82 folio_set_has_hwpoisoned __split_folio_to_order __split_unmapped_folio __folio_split truncate_inode_partial_folio (shmem hole-punch / MADV_REMOVE) Reproduced by syzkaller: hwpoison-inject a few subpages of a large shmem folio, then MADV_REMOVE (fallocate punch hole) on the same range, which splits the partial folio to a non-zero order. memory_failure() tries to split the poisoned folio to order 0 first, but that split is best-effort; when it fails the folio is left large with PG_has_hwpoisoned set, the case |
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Wei Yang
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f84ca9b188 |
mm/page_vma_mapped: fix device-private PMD handling
Commit |
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SJ Park
|
14afcf67dc |
MAINTAINERS: s/SeongJae/SJ/
My legal and preferred first names are SeongJae and SJ, respectively. I was using the legal name for commits and tags, while using the preferred name for conversations. It sometimes confuses people including myself. Consistently use the preferred name. Together remove copyright notes on files. Those are only confusing for people who are not familiar with the law. Meanwhile, we can infer the information in a better way from git logs and public information. Link: https://lore.kernel.org/20260630013820.143366-1-sj@kernel.org Signed-off-by: SJ Park <sj@kernel.org> Acked-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Mike Rapoport (Microsoft)
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3c58f641e8 |
userfaultfd: prevent registration of special VMAs
Vova Tokarev says:
userfaultfd allows registration on shadow stack VMAs. With userfaultfd
access, you can register on the shadow stack, discard a page ... and
inject a page with chosen return addresses via UFFDIO_COPY.
Update vma_can_userfault() to reject VM_SHADOW_STACK.
While on it, also reject VM_SPECIAL so that if a driver would implement
vm_uffd_ops, it wouldn't be possible to register special VMAs with
userfaultfd.
Since VM_SPECIAL includes VM_DONTEXPAND which is set but hugetlb, exclude
hugetlb VMAs from the check for VM_SPECIAL.
Link: https://lore.kernel.org/20260618095017.2553004-1-rppt@kernel.org
Fixes:
|
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Pedro Falcato
|
e187bc02f8 |
mm: do file ownership checks with the proper mount idmap
Ever since idmapped mounts were introduced, inode ownership checks (for
side-channel protection) in mincore() and madvise(MADV_PAGEOUT) were done
against the nop_mnt_idmap, which completely ignores the file's mount's
idmap. This results in odd edgecases like:
1) mount/bind-mount with an idmap userA:userB:1
2) userB runs an owner_or_capable() check on file that is owned by userA
on-disk/in-memory, but owned by userB after idmap translation
3) owner_or_capable() mysteriously fails as the correct idmap wasn't supplied
In the case of mincore/madvise MADV_PAGEOUT, this is usually benign,
because file_permission(file, MAY_WRITE) will probably succeed, as it uses
the proper idmap internally, but it does not need to be the case on e.g a
0444 file where even the owner itself doesn't have permissions to write to
it.
Since this is clearly not trivial to get right, introduce a
file_owner_or_capable() that can carry the correct semantics, and switch
the various users in mm to it.
The issue was found by manual code inspection & an off-list discussion
with Jan Kara.
Link: https://lore.kernel.org/20260625153853.913949-1-pfalcato@suse.de
Fixes:
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SeongJae Park
|
35d4a3cf70 |
mm/damon/ops-common: handle extreme intervals in damon_hot_score()
Fix three issues in damon_hot_score() that comes from wrong handling of
extreme (zero or too high) monitoring intervals user setup.
When the user sets sampling interval zero, damon_max_nr_accesses(), which
is called from damon_hot_score(), causes a divide-by-zero. Needless to
say, it is a problem.
When the user sets the aggregation interval zero, the function returns
zero. It is wrong, since the real maximum nr_acceses in the setup should
be one. Worse yet, it can cause another divide-by-zero from its caller,
damon_hot_score(), since it uses damon_max_nr_accesses() return value as a
denominator.
When the user sets the aggregation interval very high, damon_hot_score()
could return a value out of [0, DAMOS_MAX_SCORE] range. Since the return
value is used as an index to the regions_score_histogram array, which is
DAMOS_MAX_SCORE+1 size, it causes out of bounds array access.
The issues can be relatively easily reproduced like below. The sysfs
write permission is required, though.
# ./damo start --damos_action lru_prio --damos_quota_space 100M \
--damos_quota_interval 1s
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/0/monitoring_attrs/intervals/sample_us
# echo 0 > contexts/0/monitoring_attrs/intervals/aggr_us
# echo commit > state
# dmesg
[...]
[ 131.329762] Oops: divide error: 0000 [#1] SMP NOPTI
[...]
[ 131.336089] RIP: 0010:damon_hot_score+0x27/0xd0
[...]
Fix the divide-by-zero intervals problems by explicitly handling the zero
intervals in damon_max_nr_accesses(). Fix the out-of-bound array access
by applying [0, DAMOS_MAX_SCORE] bounds before returning from
damon_hot_score().
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260623135834.67189-1-sj@kernel.org
Link: https://lore.kernel.org/20260619202459.145010-1-sj@kernel.org [1]
Fixes:
|
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|
Zi Yan
|
7da7d599b8 |
mm/compaction: handle free_pages_prepare() properly in compaction_free()
free_pages_prepare() can fail but compaction_free() does not handle the
failure case. Failed pages should not be added back to cc->freepages for
future use, since they can be either PageHWPoison or free_page_is_bad()
and might cause data corruption.
Link: https://lore.kernel.org/20260622-handle_free_pages_prepare_in_compaction_free-v1-1-fcf3b14abcf7@nvidia.com
Fixes:
|
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SeongJae Park
|
05ea83ee88 |
mm/damon/sysfs-schemes: put stats for scheme_add_dirs() internal error
damon_sysfs_scheme_add_dirs() setup the tried_regions directory after the
stats directory setup is completed. When the tried_regions directory
setup is failed, the setup function ensures the reference for the tried
regions directory is released. Hence the error path should put references
on setup succeeded directory objects, starting from the stats directory.
However, the error path is putting the tried_regions directory instead of
the stats directory.
As a direct result, the stats directory object is leaked. Worse yet, if
the tried_regions directory setup failed from the initial allocation, the
scheme->tried_regions field remains uninitialized. The following
kobject_put(&scheme->tried_regions->kobj) call in the error path will
dereference the uninitialized memory. The setup failures should not be
common. But once it happens, the consequence is quite bad.
Fix this issue by correctly putting the stats directory instead of the
tried_regions directory.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260618005650.83868-3-sj@kernel.org
Link: https://lore.kernel.org/20260617005223.96813-1-sj@kernel.org [1]
Fixes:
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SeongJae Park
|
d58fdbe37a |
mm/damon/sysfs-schemes: fix dir put orders in access_pattern_add_dirs()
Patch series "mm/damon/sysfs-schemes: fix wrong directories put orders in
error paths".
Error paths of damon_sysfs_access_pattern_add_dirs() and
damon_sysfs_scheme_add_dirs() functions put references to directories in
wrong orders. As a result, uninitialized memory dereference and/or
memory leak can happen. Fix those.
This patch (of 2):
In access_pattern_add_dirs(), error handling path puts references starting
from setup failed directories. If the failure happpened from the initial
allication in the setup functions, uninitialized memory dereference
happen. The allocation failures will not commonly happen, but the
consequence is quite bad. Fix the wrong reference put orders.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260618005650.83868-2-sj@kernel.org
Link: https://lore.kernel.org/20260617060005.86852-1-sj@kernel.org [1]
Fixes:
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Qi Zheng
|
e30453c61e |
mm: shrinker: fix NULL pointer dereference in debugfs
shrinker_debugfs_add() creates both "count" and "scan" debugfs files
unconditionally.
That assumes every shrinker implements both count_objects() and
scan_objects(), which is not guaranteed. For example, the xen-backend
shrinker sets count_objects() but leaves scan_objects() NULL, so writing
to its scan file calls through a NULL function pointer and panics the
kernel:
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
Call Trace:
<TASK>
shrinker_debugfs_scan_write+0x12e/0x270
full_proxy_write+0x5f/0x90
vfs_write+0xde/0x420
? filp_flush+0x75/0x90
? filp_close+0x1d/0x30
? do_dup2+0xb8/0x120
ksys_write+0x68/0xf0
? filp_flush+0x75/0x90
do_syscall_64+0xb3/0x5b0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The count path has the same issue in principle if a shrinker omits
count_objects().
To fix it, only create "count" and "scan" debugfs files when the
corresponding callbacks are present.
Link: https://lore.kernel.org/20260617090052.27325-1-qi.zheng@linux.dev
Fixes:
|
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Qi Zheng
|
65476d31d8 |
mm: shrinker: fix shrinker_info teardown race with expansion
expand_shrinker_info() iterates all visible memcgs under shrinker_mutex,
including memcgs that have not finished ->css_online() yet.
Once pn->shrinker_info has been published, teardown must stay serialized
with expand_shrinker_info() until that memcg is either fully online or no
longer visible to iteration. Today alloc_shrinker_info() breaks that rule
by dropping shrinker_mutex before freeing a partially initialized
shrinker_info array, which may cause the following race:
CPU0 CPU1
==== ====
css_create
--> list_add_tail_rcu(&css->sibling, &parent_css->children);
online_css
--> mem_cgroup_css_online
--> alloc_shrinker_info
--> alloc node0 info
rcu_assign_pointer(C->node0->shrinker_info, old0)
alloc node1 info -> FAIL -> goto err
mutex_unlock(shrinker_mutex)
shrinker_alloc()
--> shrinker_memcg_alloc
--> mutex_lock(shrinker_mutex)
expand_shrinker_info
--> mem_cgroup_iter see the memcg
expand_one_shrinker_info
--> old0 = C->node0->shrinker_info
memcpy(new->unit, old0->unit, ...);
free_shrinker_info
--> kvfree(old0);
/* double free !! */
kvfree_rcu(old0, rcu);
The same problem exists later in mem_cgroup_css_online(). If
alloc_shrinker_info() succeeds but a subsequent objcg allocation fails,
the free_objcg -> free_shrinker_info() unwind path tears down the already
published pn->shrinker_info arrays without shrinker_mutex. The
expand_one_shrinker_info() can race with that teardown in the same way,
leading to use-after-free or double-free of the old shrinker_info.
Fix this by serializing shrinker_info teardown with shrinker_mutex, and by
keeping alloc_shrinker_info() error cleanup inside the locked section.
Link: https://lore.kernel.org/20260617085658.27096-1-qi.zheng@linux.dev
Fixes:
|
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Linus Torvalds
|
a142da0b2d |
block-7.2-20260625
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Merge tag 'block-7.2-20260625' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block fixes from Jens Axboe:
- blk-cgroup locking rework and fixes:
- fix a use-after-free in __blkcg_rstat_flush()
- defer freeing policy data until after an RCU grace period
- defer the blkcg css_put until the blkg is unlinked from
the queue
- unwind the queue_lock nesting under RCU / blkcg->lock
across the lookup, create, associate and destroy paths
- NVMe fixes via Keith:
- Fix a crash and memory leak during invalid cdev teardown,
and related cdev cleanups (Maurizio, John)
- nvmet fixes: handle TCP_CLOSING in the tcp state_change
handler, reject short AUTH_RECEIVE buffers, handle inline
data with a nonzero offset in rdma, fix an sq refcount leak,
and allocate ana_state with the port (Maurizio, Michael,
Bryam, Wentao, Rosen)
- nvme-fc fix to not cancel requests on an IO target before it
is initialized (Mohamed)
- nvme-apple fix to prevent shared tags across queues on Apple
A11 (Nick)
- Various smaller fixes and cleanups (John)
- MD fixes via Yu Kuai:
- raid1/raid10 fixes for writes_pending and barrier reference
leaks on write and discard failures, plus REQ_NOWAIT handling
fixes (Abd-Alrhman)
- raid5 discard accounting and validation, and a batch of fixes
for stripe batch races (Yu Kuai, Chen)
- Protect raid1 head_position during read balancing (Chen)
- block bio-integrity fixes: correct an error injection static key
decrement, fix GFP flag confusion in bio_integrity_alloc_buf(), and
handle REQ_OP_ZONE_APPEND in __bio_integrity_action() (Christoph)
- Fixes for bio_iov_iter_bounce_write(): revert the iov_iter after a
short copy, and respect the iov_iter nofault flag (Qu)
- Invalidate the cached plug timestamp after a task switch, and clear
PF_BLOCK_TS in copy_process() (Usama)
- Fix the IORING_URING_CMD_REISSUE flags check in blkdev_uring_cmd()
(Yitang)
- Remove a redundant plug in __submit_bio() (Wen)
- Don't warn when reclassifying a busy socket lock in nbd (Deepanshu)
* tag 'block-7.2-20260625' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (45 commits)
block: handle REQ_OP_ZONE_APPEND in __bio_integrity_action
block: fix GFP_ flags confusion in bio_integrity_alloc_buf
block, bfq: don't grab queue_lock to initialize bfq
mm/page_io: don't nest queue_lock under rcu in bio_associate_blkg_from_page()
blk-cgroup: don't nest queue_lock under blkcg->lock in blkcg_destroy_blkgs()
blk-cgroup: don't nest queue_lock under rcu in bio_associate_blkg()
blk-cgroup: don't nest queue_lock under rcu in blkg_lookup_create()
blk-cgroup: don't nest queue_lock under rcu in blkcg_print_blkgs()
blk-cgroup: delay freeing policy data after rcu grace period
blk-cgroup: protect iterating blkgs with blkcg->lock in blkcg_print_stat()
md/raid5: avoid R5_Overlap races while breaking stripe batches
md/raid5: use stripe state snapshot in break_stripe_batch_list()
blk-cgroup: defer blkcg css_put until blkg is unlinked from queue
blk-cgroup: fix UAF in __blkcg_rstat_flush()
block, bfq: protect async queue reset with blkcg locks
nbd: don't warn when reclassifying a busy socket lock
block: fix incorrect error injection static key decrement
md/raid5: let stripe batch bm_seq comparison wrap-safe
md/raid1: protect head_position for read balance
md/raid1: free r1_bio when REQ_NOWAIT is set and read would block on retry
...
|
||
|
Yu Kuai
|
f928145cbc |
mm/page_io: don't nest queue_lock under rcu in bio_associate_blkg_from_page()
Take a css reference under RCU, drop RCU, and then associate the bio with the blkg. This avoids nesting queue_lock under RCU and prepares to protect blkcg with blkcg_mutex instead of queue_lock. Use css_tryget() instead of css_tryget_online() so swap writeback for pages charged to a dying memcg still passes the dying css to bio_associate_blkg_from_css(). That preserves the existing closest-live ancestor fallback instead of charging those bios to the root blkg. Signed-off-by: Yu Kuai <yukuai@fygo.io> Link: https://patch.msgid.link/c910d2c39d3ec97f67de68af636a52394342d55f.1780621988.git.yukuai@fygo.io Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
|
Linus Torvalds
|
a1a8bab741 |
mm.git review status for linus..mm-stable
Everything: Total patches: 118 Reviews/patch: 1.57 Reviewed rate: 62% Excluding DAMON: Total patches: 117 Reviews/patch: 1.58 Reviewed rate: 63% Excluding DAMON and selftests: Total patches: 42 Reviews/patch: 3.14 Reviewed rate: 92% Patch series in this merge: - The 14 patch series "khugepaged: add mTHP collapse support" from Nico Pache provides khugepaged with the capability to collapse anonymous memory regions to mTHPs. - The 14 patch series "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable files" from Zi Yan ends up removing the READ_ONLY_THP_FOR_FS check in file_thp_enabled(), so that khugepaged and MADV_COLLAPSE can run on FSes with PMD THP pagecache support even without READ_ONLY_THP_FOR_FS enabled. - The 55 patch series "make MM selftests more CI friendly" from Mike Rapoport provides general fixes and cleanups to the MM selftests. It also moves more MM selftests uder the kselftest framework, making them more amenable to ongoing CI testing. - The 13 patch series "selftests/mm: fix failures and robustness improvements" from Sayali Patil fixes several issues in MM selftests which were revealed by powerpc 64k pagesize. - The 3 patch series "selftests/mm: assorted fixes for hmm-tests" from Sayali Patil fixes more 64k pagesize issues in the MM selftests. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCajqsgwAKCRDdBJ7gKXxA jlNoAP0bM125zRNpqy13hUYfofQQg8lC9k7cfEHqVtvD/dpaKgD/Xbjd8AUGbwjs qoj3nNmUOfGFPubPZsU6YSFyVsYfzwM= =T44n -----END PGP SIGNATURE----- Merge tag 'mm-stable-2026-06-23-08-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - "khugepaged: add mTHP collapse support" (Nico Pache) Provide khugepaged with the capability to collapse anonymous memory regions to mTHPs - "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable files" (Zi Yan) Remove the READ_ONLY_THP_FOR_FS check in file_thp_enabled(), so that khugepaged and MADV_COLLAPSE can run on filesystems with PMD THP pagecache support even without READ_ONLY_THP_FOR_FS enabled - "make MM selftests more CI friendly" (Mike Rapoport) General fixes and cleanups to the MM selftests. Also move more MM selftests under the kselftest framework, making them more amenable to ongoing CI testing - "selftests/mm: fix failures and robustness improvements" and "selftests/mm: assorted fixes for hmm-tests" (Sayali Patil) Fix several issues in MM selftests which were revealed by powerpc 64k pagesize * tag 'mm-stable-2026-06-23-08-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (118 commits) Revert "mm: limit filemap_fault readahead to VMA boundaries" mm/vmscan: pass NULL to trace vmscan node reclaim mm: use mapping_mapped to simplify the code selftests/mm: fix exclusive_cow test fork() handling selftests/mm: remove hardcoded THP sizing assumptions in hmm tests selftests/mm: allow PUD-level entries in compound testcase of hmm tests mm/gup_test: reject wrapped user ranges mm/page_frag: reject invalid CPUs in page_frag_test mm/damon/core: always put unsuccessfully committed target pids mm: page_isolation: avoid unsafe folio reads while scanning compound pages mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show() selftests: mm: fix and speedup "droppable" test mm: merge writeout into pageout MAINTAINERS: add Hao Ge as reviewer for codetag and alloc_tag selftests/mm: clarify alternate unmapping in compaction_test selftests/mm: move hwpoison setup into run_test() and silence modprobe output for memory-failure category selftests/mm: skip uffd-stress test when nr_pages_per_cpu is zero selftests/mm: skip uffd-wp-mremap if UFFD write-protect is unsupported selftests/mm: ensure destination is hugetlb-backed in hugetlb-mremap selftest/mm: register existing mapping with userfaultfd in hugetlb-mremap ... |
||
|
Linus Torvalds
|
335c347686 |
slab changes for 7.2 - part 2
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Merge tag 'slab-for-7.2-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull more slab updates from Vlastimil Babka:
- Introduce and wire up a new alloc_flags parameter for modifying
slab-specific behavior without adding or reusing gfp flags. Also
introduce slab_alloc_context to keep function parameter bloat in
check. Both are similar to what the page allocator does.
kmalloc_flags() exposes alloc_flags for mm-internal users.
- SLAB_ALLOC_NOLOCK flag is used to implement kmalloc_nolock()
behavior without relying on lack of __GFP_RECLAIM, which caused
false positives with workarounds like
|
||
|
Linus Torvalds
|
2e05544060 |
mm.git review status for mm-hotfixes-stable..mm-nonmm-stable
Everything:
Total patches: 108
Reviews/patch: 0.84
Reviewed rate: 75%
Patch series in this merge:
- The 2 patch series "taskstats: fix TGID dead-thread stat retention"
from Yiyang Chen fixes a taskstats TGID aggregation bug where fields
added in the TGID query path were not preserved after thread exit, and
adds a kselftest covering the regression.
- The 2 patch series "lib/tests: string_helpers: Slight improvements"
from Andy Shevchenko improves lib/tests/string_helpers_kunit.c a little.
- The 2 patch series "lib/base64: decode fixes" from Josh Law addreesses
minor issues in lib/base64.c.
- The 3 patch series "selftests/filelock: Make output more kselftestish"
from Mark Brown makes the output from the ofdlocks test a bit easier for
tooling to work with, and also ignores the generated file.
- The 3 patch series "uaccess: unify inline vs outline
copy_{from,to}_user() selection" from Yury Norov simplifies the usercopy
code by removing the selectability of inlining copy_{from,to}_user().
- The 5 patch series "ocfs2: validate inline xattr header consumers"
from ZhengYuan Huang fixes a number of possible issues in the ocfs2
xattr code.
- The 8 patch series "lib and lib/cmdline enhancements" from Dmitry
Antipov provides additional robustness checking in the cmdline handling
code and its in-kernel testing and selftests.
- The 18 patch series "cleanup the RAID6 P/Q library" from Christoph
Hellwig cleans up the RAID6 P/Q library to match the recent updates to
the RAID 5 XOR library and other CRC/crypto libraries.
- The 3 patch series "ocfs2: harden inode validators against forged
metadata" from Michael Bommarito adds three structural checks to OCFS2
dinode validation so malformed on-disk fields are rejected before
ocfs2_populate_inode() copies them into the in-core inode.
- The 2 patch series "lib/raid: replace __get_free_pages() call with
kmalloc()" from Mike Rapoport cleans up the lib/raid code by using
kmalloc() in more places.
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Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)
Fix a taskstats TGID aggregation bug where fields added in the TGID
query path were not preserved after thread exit, and adds a kselftest
covering the regression.
- "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)
Improve lib/tests/string_helpers_kunit.c a little
- "lib/base64: decode fixes" (Josh Law)
Address minor issues in lib/base64.c
- "selftests/filelock: Make output more kselftestish" (Mark Brown)
Make the output from the ofdlocks test a bit easier for tooling to
work with. Also ignore the generated file
- "uaccess: unify inline vs outline copy_{from,to}_user() selection"
(Yury Norov)
Simplify the usercopy code by removing the selectability of inlining
copy_{from,to}_user().
- "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)
Fix a number of possible issues in the ocfs2 xattr code
- "lib and lib/cmdline enhancements" (Dmitry Antipov)
Provide additional robustness checking in the cmdline handling code
and its in-kernel testing and selftests
- "cleanup the RAID6 P/Q library" (Christoph Hellwig)
Clean up the RAID6 P/Q library to match the recent updates to the
RAID 5 XOR library and other CRC/crypto libraries
- "ocfs2: harden inode validators against forged metadata" (Michael
Bommarito)
Add three structural checks to OCFS2 dinode validation so malformed
on-disk fields are rejected before ocfs2_populate_inode() copies them
into the in-core inode
- "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
Rapoport)
Clean up the lib/raid code by using kmalloc() in more places
* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
lib: interval_tree_test: validate benchmark parameters
ocfs2: avoid moving extents to occupied clusters
treewide: fix transposed "sign" typos and update spelling.txt
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
fat: reject BPB volumes whose data area starts beyond total sectors
selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
lib/test_firmware: allocate the configured into_buf size
fs: efs: remove unneeded debug prints
checkpatch: cuppress warnings when Reported-by: is followed by Link:
MAINTAINERS: add Alexander as a kcov reviewer
mailmap: update Alexander Sverdlin's Email addresses
fs: fat: inode: replace sprintf() with scnprintf()
ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
ocfs2/dlm: require a ref for locking_state debugfs open
ocfs2: reject FITRIM ranges shorter than a cluster
ocfs2: validate fast symlink target during inode read
ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
...
|
||
|
Lorenzo Stoakes
|
13a1e1a618 |
Revert "mm: limit filemap_fault readahead to VMA boundaries"
This reverts commit |
||
|
Ben Dooks
|
44238b122a |
mm/vmscan: pass NULL to trace vmscan node reclaim
The tracepoint for node relcaims takes a `struct mem_cgroup *` as the third argument, so pass NULL instead of 0 to fix warning about using an integer as a pointer. Fixes the following warnings: mm/vmscan.c:6753:66: warning: Using plain integer as NULL pointer mm/vmscan.c:6757:58: warning: Using plain integer as NULL pointer mm/vmscan.c:7818:60: warning: Using plain integer as NULL pointer Link: https://lore.kernel.org/20260616095906.210016-1-ben.dooks@codethink.co.uk Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Huang Shijie
|
c565c009d0 |
mm: use mapping_mapped to simplify the code
Use mapping_mapped() to simplify the code, make the code tidy and clean. Link: https://lore.kernel.org/20260612073032.33228-1-huangsj@hygon.cn Signed-off-by: Huang Shijie <huangsj@hygon.cn> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Muchun Song <muchun.song@linux.dev> Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Samuel Moelius
|
e8ae6fd670 |
mm/gup_test: reject wrapped user ranges
gup_test accepts an address and size from the debugfs ioctl and repeatedly compares against addr + size. If that addition wraps, the loop can be skipped and the ioctl returns success with size rewritten to zero. Compute the end address once with overflow checking and use that checked end for the loop bounds. Assisted-by: Codex:gpt-5.5-cyber-preview Link: https://lore.kernel.org/20260609004814.1240586.6294d614ac80.gup-test-range-end-wrap@trailofbits.com Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
6a66c557a2 |
mm/damon/core: always put unsuccessfully committed target pids
damon_commit_target() puts and gets the destination and the source target
pids. It puts the destination target pid because it will be overwritten
by the source target pid. It gets the source pid because the caller is
supposed to eventually put the pids. In more detail, the caller will call
damon_destroy_ctx() after damon_commit_ctx() to destroy the entire source
context. And in this case, [f]vaddr operation set's cleanup_target()
callback will put the pids.
The commit operation is made at the context level. The operation can fail
in multiple places including in the middle and after the targets commit
operations. For any such failures, immediately the error is returned to
the damon_commit_ctx() caller. If some or all of the source target pids
were committed to the destination during the unsuccessful context commit
attempt, those pids should be put twice.
The source context will do the put operations using the above explained
routine. However, let's suppose the destination context was not
originally using [f]vaddr operation set and the commit failed before the
ops of the source context is committed. The destination does not have the
cleanup_target() ops callback, so it cannot put the pids via the
damon_destroy_ctx().
As a result, the pids are leaked. The issue in the real world would be
not very common. The commit feature is for changing parameters of running
DAMON context while inheriting internal status like the monitoring
results. The monitoring results of a physical address range ain't have
things that are beneficial to be inherited to a virtual address ranges
monitoring. So the problem-causing DAMON control would be not very common
in the real world. That said, it is a supported feature. And
damon_commit_target() failure due to memory allocation is relatively
realistic [1] if there are a huge number of target regions.
Fix by putting the pids in the commit operation in case of the failures.
The issue was discovered [2] by Sashiko.
Link: https://lore.kernel.org/20260605013849.83750-1-sj@kernel.org
Link: https://lore.kernel.org/20260603112306.58490-1-akinobu.mita@gmail.com [1]
Link: https://lore.kernel.org/20260320020056.835-1-sj@kernel.org [2]
Fixes:
|
||
|
Kaitao Cheng
|
878f41243c |
mm: page_isolation: avoid unsafe folio reads while scanning compound pages
page_is_unmovable() can inspect compound pages without holding a folio
reference or any lock. The folio can therefore be freed, split or reused
while the scanner is still looking at it.
The existing HugeTLB handling already avoids folio_hstate() for this
reason, but it still derives the hstate from folio_size() and later
derives the scan step from folio_nr_pages() and folio_page_idx(). These
helpers rely on the folio still being a valid folio head. If the folio
changed concurrently, the scanner can read inconsistent folio metadata and
compute a wrong step. In the worst case, folio_nr_pages() can return 1
for what used to be a tail page and the subtraction from folio_page_idx()
can underflow.
There is a similar issue for non-Hugetlb compound pages: folio_test_lru()
expects a valid folio. If the previously observed head page has been
reused as a tail page of another compound page, the folio flag checks can
trigger VM_BUG_ON_PGFLAGS().
Read the compound order once with compound_order(), reject obviously bogus
orders, and derive the hstate and scan step from that order instead of
querying folio size information again. Also use PageLRU(page), which is
safe for the page being scanned, instead of folio_test_lru() on a
potentially stale folio pointer.
Treat an unknown HugeTLB hstate as unmovable so the scanner does not try
to skip over an unstable HugeTLB folio.
Link: https://lore.kernel.org/20260602130755.38794-1-kaitao.cheng@linux.dev
Fixes:
|
||
|
Shakeel Butt
|
b902890c62 |
mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()
Reading the debugfs "count" file of a memcg-aware shrinker can sleep
inside an RCU read-side critical section:
BUG: sleeping function called from invalid context at kernel/cgroup/rstat.c:421
RCU nest depth: 1, expected: 0
css_rstat_flush
mem_cgroup_flush_stats
zswap_shrinker_count
shrinker_debugfs_count_show
shrinker_debugfs_count_show() invokes the ->count_objects() callback under
rcu_read_lock(). The zswap callback flushes memcg stats via
css_rstat_flush(), which may sleep, so it must not run under RCU.
The RCU lock is not needed here. mem_cgroup_iter() takes RCU internally
and returns a memcg holding a css reference (dropped on the next iteration
or by mem_cgroup_iter_break()), so the memcg stays alive without it. The
shrinker is kept alive by the open debugfs file: shrinker_free() removes
the debugfs entries via debugfs_remove_recursive(), which waits for
in-flight readers to drain, before call_rcu(..., shrinker_free_rcu_cb).
The sibling "scan" handler already invokes the sleeping ->scan_objects()
callback with no RCU section.
Drop the rcu_read_lock()/rcu_read_unlock().
Link: https://lore.kernel.org/20260610232048.62930-1-shakeel.butt@linux.dev
Fixes:
|
||
|
Christoph Hellwig
|
6f64c06f43 |
mm: merge writeout into pageout
writeout is only called from pageout, and a straight flow at the end, so merge the two functions. Link: https://lore.kernel.org/20260601113449.3464734-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Baoquan He <baoquan.he@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Chen Wandun
|
b89a641056 |
mm/khugepaged: avoid underflow in madvise_collapse for sub-PMD MADV_COLLAPSE
madvise_collapse() computes the THP-aligned window:
hstart = ALIGN(start, HPAGE_PMD_SIZE); /* round up */
hend = ALIGN_DOWN(end, HPAGE_PMD_SIZE); /* round down */
The following case will cause hstart > hend, and result in underflow in
the return statement, avoid it by returning zero early when hstart > hend.
The return value is due to input is valid to madvise(), and there is
nothing to collapse.
madvise(PMD-aligned + PAGE_SIZE, PAGE_SIZE, MADV_COLLAPSE);
In addition, kmalloc_obj(), mmgrab() and lru_add_drain_all() are
unnecessary when hstart == hend, so skip these operations by returning
early too.
Link: https://lore.kernel.org/20260513055428.1664898-1-chenwandun@lixiang.com
Signed-off-by: Chen Wandun <chenwandun@lixiang.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Zi Yan
|
1b6444331b |
mm/khugepaged: enable clean pagecache folio collapse for writable files
collapse_file() is capable of collapsing pagecache folios from writable files to PMD folios. Now enable clean pagecache folio collapse in addition to read-only pagecache folio collapse by removing the inode_is_open_for_write() from file_thp_enabled() and only performing filemap_flush() if the file is read-only. This means userspace needs to explicitly flush the content of pagecache folios before khugepaged can collapse the folios, or use madvise(MADV_COLLAPSE), which does the flush in the retry. The reason is that blindly enabling dirty pagecache folio from writable files collapse makes khugepaged flush these folios all the time. It is undesirable to cause system level pagecache flushes. To properly support dirty pagecache folio collapse, filemap_flush() needs to be avoided. Potentially, merging associated buffer instead of dropping it with filemap_release_folio() might be needed. NOTE: this breaks khugepaged selftests for writable file pagecache collapse, which is set to fail all the time. The next commit fixes it. Link: https://lore.kernel.org/20260517135416.1434539-14-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand (Arm) <david@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Zi Yan
|
15e2258e25 |
mm/truncate: use folio_split() in truncate_inode_partial_folio()
After READ_ONLY_THP_FOR_FS is removed, FS either supports large folio or not. folio_split() can be used on a FS with large folio support without worrying about getting a THP on a FS without large folio support. When READ_ONLY_THP_FOR_FS was present, a PMD large pagecache folio can appear in a FS without large folio support after khugepaged or madvise(MADV_COLLAPSE) creates it. During truncate_inode_partial_folio(), such a PMD large pagecache folio is split and if the FS does not support large folio, it needs to be split to order-0 ones and could not be split non uniformly to ones with various orders. try_folio_split_to_order() was added to handle this situation by checking folio_check_splittable(..., SPLIT_TYPE_NON_UNIFORM) to detect if the large folio is created due to READ_ONLY_THP_FOR_FS and the FS does not support large folio. Now READ_ONLY_THP_FOR_FS is removed, all large pagecache folios are created with FSes supporting large folio, this function is no longer needed and all large pagecache folios can be split non uniformly. Link: https://lore.kernel.org/20260517135416.1434539-10-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
7c16f524f2 |
mm/huge_memory: remove folio split check for READ_ONLY_THP_FOR_FS
Without READ_ONLY_THP_FOR_FS, large file-backed folios cannot be created by a FS without large folio support. The check is no longer needed. Link: https://lore.kernel.org/20260517135416.1434539-9-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
044925f9b5 |
mm: fs: remove filemap_nr_thps*() functions and their users
They are used by READ_ONLY_THP_FOR_FS to handle writes to FSes without large folio support, so that read-only THPs created in these FSes are not seen by the FSes when the underlying fd becomes writable. Now read-only PMD THPs only appear in a FS with large folio support and the supported orders include PMD_ORDER. READ_ONLY_THP_FOR_FS was using mapping->nr_thps, inode->i_writecount, and smp_mb() to prevent writes to a read-only THP and collapsing writable folios into a THP. In collapse_file(), mapping->nr_thps is increased, then smp_mb(), and if inode->i_writecount > 0, collapse is stopped, while do_dentry_open() first increases inode->i_writecount, then a full memory fence, and if mapping->nr_thps > 0, all read-only THPs are truncated. Now this mechanism can be removed along with READ_ONLY_THP_FOR_FS code, since a dirty folio check has been added after try_to_unmap() in collapse_file() to prevent dirty folios from being collapsed as clean. Link: https://lore.kernel.org/20260517135416.1434539-7-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
e4df0f37bd |
mm: remove READ_ONLY_THP_FOR_FS Kconfig option
After removing READ_ONLY_THP_FOR_FS check in file_thp_enabled(), khugepaged and MADV_COLLAPSE can run on FSes with PMD THP pagecache support even without READ_ONLY_THP_FOR_FS enabled. Remove the Kconfig first so that no one can use READ_ONLY_THP_FOR_FS as upcoming commits remove mapping->nr_thps, which its safe guard mechanism relies on. Link: https://lore.kernel.org/20260517135416.1434539-6-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Nico Pache <npache@redhat.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
efc36a7153 |
mm/khugepaged: remove READ_ONLY_THP_FOR_FS check in hugepage_enabled()
Remove the READ_ONLY_THP_FOR_FS gate and khugepaged for file-backed pmd-sized hugepages are enabled by the global transparent hugepage control. khugepaged can still be enabled by per-size control for anon and shmem when the global control is off. Add shmem_hpage_pmd_enabled() stub for !CONFIG_SHMEM to remove IS_ENABLED(SHMEM) in hugepage_enabled(). Clean up hugepage_enabled() by moving anon code to anon_hpage_enabled(). Link: https://lore.kernel.org/20260517135416.1434539-5-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Nico Pache <npache@redhat.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
8a088263a0 |
mm/huge_memory: remove READ_ONLY_THP_FOR_FS from file_thp_enabled()
Replace it with a check on the max folio order of the file's address space mapping, making sure PMD folio is supported. Keep the inode open-for-write check, since even if collapse_file() now makes sure all to-be-collapsed folios are clean and the created PMD file THP can be handled by FSes properly, the filemap_flush() could perform undesirable write back. Link: https://lore.kernel.org/20260517135416.1434539-4-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Nico Pache <npache@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
4e3d769bf0 |
mm/khugepaged: add folio dirty check after try_to_unmap()
This check ensures the correctness of read-only PMD folio collapse after it is enabled for all FSes supporting PMD pagecache folios and replaces READ_ONLY_THP_FOR_FS. READ_ONLY_THP_FOR_FS only supports read-only fd and uses mapping->nr_thps and inode->i_writecount to prevent any write to read-only to-be-collapsed folios. In upcoming commits, READ_ONLY_THP_FOR_FS will be removed and the aforementioned mechanism will go away too. To ensure khugepaged functions as expected after the changes, skip if any folio is dirty after try_to_unmap(), since a dirty folio at that point means this read-only folio can get writes between try_to_unmap() and try_to_unmap_flush() via cached TLB entries and khugepaged does not support writable pagecache folio collapse yet. Link: https://lore.kernel.org/20260517135416.1434539-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Nico Pache <npache@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Zi Yan
|
cd2d3d1f26 |
mm/khugepaged: remove READ_ONLY_THP_FOR_FS check
Patch series "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable files", v6. This patch (of 14): collapse_file() requires FSes supporting large folio with at least PMD_ORDER, so replace the READ_ONLY_THP_FOR_FS check with that. MADV_COLLAPSE ignores shmem huge config, so exclude the check for shmem. While at it, replace VM_BUG_ON with VM_WARN_ON_ONCE. Add a helper function mapping_pmd_folio_support() for FSes supporting large folio with at least PMD_ORDER. Link: https://lore.kernel.org/20260517135416.1434539-1-ziy@nvidia.com Link: https://lore.kernel.org/20260517135416.1434539-2-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Nico Pache <npache@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Barry Song <baohua@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lance Yang
|
c85418be96 |
mm/khugepaged: fix PMD collapse swap PTE accounting
mthp_collapse() uses mthp_present_ptes to decide whether a range has
enough occupied PTEs to try collapse. Swap PTEs accepted by
collapse_scan_pmd() are counted in unmapped, but are not represented in
mthp_present_ptes.
When lower orders are enabled, collapse_scan_pmd() relaxes max_ptes_none
so the scan can cover the whole PMD and build the bitmap. mthp_collapse()
then checks the PMD-order candidate using the bitmap.
With max_ptes_none set to 0, a range with 511 present PTEs and one swap
PTE no longer reaches collapse_huge_page(), even though PMD collapse can
handle swap PTEs up to max_ptes_swap.
Account unmapped PTEs only for PMD order. PMD collapse supports swap PTEs
through max_ptes_swap, while lower-order mTHP collapse does not currently
support non-present PTEs. Keep non-present PTEs out of the lower-order
eligibility check.
Link: https://lore.kernel.org/20260609120443.71864-1-lance.yang@linux.dev
Fixes:
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Baolin Wang
|
b7f16963ef |
mm/khugepaged: run khugepaged for all orders
If any order (m)THP is enabled we should allow running khugepaged to attempt scanning and collapsing mTHPs. In order for khugepaged to operate when only mTHP sizes are specified in sysfs, we must modify the predicate function that determines whether it ought to run to do so. This function is currently called hugepage_pmd_enabled(), this patch renames it to hugepage_enabled() and updates the logic to check to determine whether any valid orders may exist which would justify khugepaged running. We must also update collapse_possible_orders() to check all orders if the vma is anonymous and the collapse is khugepaged. After this patch khugepaged mTHP collapse is fully enabled. Link: https://lore.kernel.org/20260605161422.213817-14-npache@redhat.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Acked-by: Usama Arif <usama.arif@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Nico Pache
|
5fea7eb1a3 |
mm/khugepaged: avoid unnecessary mTHP collapse attempts
There are cases where, if an attempted collapse fails, all subsequent orders are guaranteed to also fail. Avoid these collapse attempts by bailing out early. Link: https://lore.kernel.org/20260605161422.213817-13-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: Usama Arif <usama.arif@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Nico Pache
|
90ed32d000 |
mm/khugepaged: introduce mTHP collapse support
Enable khugepaged to collapse to mTHP orders. This patch implements the
main scanning logic using a bitmap to track occupied pages and the
algorithm to find optimal collapse sizes.
Previous to this patch, PMD collapse had 3 main phases, a light weight
scanning phase (mmap_read_lock) that determines a potential PMD collapse,
an alloc phase (mmap unlocked), then finally heavier collapse phase
(mmap_write_lock).
To enabled mTHP collapse we make the following changes:
During PMD scan phase, track occupied pages in a bitmap. When mTHP orders
are enabled, we remove the restriction of max_ptes_none during the scan
phase to avoid missing potential mTHP collapse candidates. Once we have
scanned the full PMD range and updated the bitmap to track occupied pages,
we use the bitmap to find the optimal mTHP size.
Implement mthp_collapse() to walk forward through the bitmap and determine
the best eligible order for each naturally-aligned region. The algorithm
starts at the beginning of the PMD range and, for each offset, tries the
highest order that fits the alignment. If the number of occupied PTEs in
that region satisfies the max_ptes_none threshold for that order, a
collapse is attempted. On failure, the order is decremented and the same
offset is retried at the next smaller size. Once the smallest enabled
order is exhausted (or a collapse succeeds), the offset advances past the
region just processed, and the next attempt starts at the highest order
permitted by the new offset's natural alignment.
The algorithm works as follows:
1) set offset=0 and order=HPAGE_PMD_ORDER
2) if the order is not enabled, go to step (5)
3) count occupied PTEs in the (offset, order) range using
bitmap_weight_from()
4) if the count satisfies the max_ptes_none threshold, attempt
collapse; on success, advance to step (6)
5) if a smaller enabled order exists, decrement order and retry
from step (2) at the same offset
6) advance offset past the current region and compute the next
order from the new offset's natural alignment via __ffs(offset),
capped at HPAGE_PMD_ORDER
7) repeat from step (2) until the full PMD range is covered
mTHP collapses reject regions containing swapped out or shared pages.
This is because adding new entries can lead to new none pages, and these
may lead to constant promotion into a higher order mTHP. A similar issue
can occur with "max_ptes_none > HPAGE_PMD_NR/2" due to a collapse
introducing at least 2x the number of pages, and on a future scan will
satisfy the promotion condition once again. This issue is prevented via
the collapse_max_ptes_none() function which imposes the max_ptes_none
restrictions above.
We currently only support mTHP collapse for max_ptes_none values of 0 and
HPAGE_PMD_NR - 1. resulting in the following behavior:
- max_ptes_none=0: Never introduce new empty pages during collapse
- max_ptes_none=HPAGE_PMD_NR-1: Always try collapse to the highest
available mTHP order
Any other max_ptes_none value will emit a warning and default mTHP
collapse to max_ptes_none=0. There should be no behavior change for PMD
collapse.
Once we determine what mTHP sizes fits best in that PMD range a collapse
is attempted. A minimum collapse order of 2 is used as this is the lowest
order supported by anon memory as defined by THP_ORDERS_ALL_ANON.
Currently madv_collapse is not supported and will only attempt PMD
collapse.
We can also remove the check for is_khugepaged inside the PMD scan as the
collapse_max_ptes_none() function handles this logic now.
Link: https://lore.kernel.org/20260605161422.213817-12-npache@redhat.com
Signed-off-by: Nico Pache <npache@redhat.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shivank Garg <shivankg@amd.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Takashi Iwai (SUSE) <tiwai@suse.de>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Nico Pache
|
2c7d0fa84d |
mm/khugepaged: introduce collapse_possible_orders helper functions
Add collapse_possible_orders() to generalize THP order eligibility. The function determines which THP orders are permitted based on collapse context (khugepaged vs madv_collapse). We also add collapse_possible() as a thin wrapper around collapse_possible_orders() that returns a bool rather than the whole bitmap. This consolidates collapse configuration logic and provides a clean interface for future mTHP collapse support where the orders may be different. Link: https://lore.kernel.org/20260605161422.213817-11-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Nico Pache
|
ceaa0b6413 |
mm/khugepaged: improve tracepoints for mTHP orders
Add the order to the mm_collapse_huge_page<_swapin,_isolate> tracepoints to give better insight into what order is being operated at for. Link: https://lore.kernel.org/20260605161422.213817-10-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Nico Pache
|
b5b8b329c4 |
mm/khugepaged: add per-order mTHP collapse failure statistics
Add three new mTHP statistics to track collapse failures for different orders when encountering swap PTEs, excessive none PTEs, and shared PTEs: - collapse_exceed_swap_pte: Increment when mTHP collapse fails due to encountering a swap PTE. - collapse_exceed_none_pte: Counts when mTHP collapse fails due to exceeding the none PTE threshold for the given order - collapse_exceed_shared_pte: Counts when mTHP collapse fails due to encountering a shared PTE. These statistics complement the existing THP_SCAN_EXCEED_* events by providing per-order granularity for mTHP collapse attempts. The stats are exposed via sysfs under `/sys/kernel/mm/transparent_hugepage/hugepages-*/stats/` for each supported hugepage size. As we currently do not support collapsing mTHPs that contain a swap or shared entry, those statistics keep track of how often we are encountering failed mTHP collapses due to these restrictions. We will add support for mTHP collapse for anonymous pages next; lets also track when this happens at the PMD level within the per-mTHP stats. Link: https://lore.kernel.org/20260605161422.213817-9-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Nico Pache
|
3a460f245f |
mm/khugepaged: skip collapsing mTHP to smaller orders
khugepaged may try to collapse a mTHP to a folio of equal or smaller size, possibly resulting in a partially mapped source folio, which is undesired. Skip these cases until we have a way to check if its ok to collapse to a smaller mTHP size (like in the case of a partially mapped folio). This check is not done during the scan phase as the current collapse order is unknown at that time. This patch is inspired by Dev Jain's work on khugepaged mTHP support [1]. Link: https://lore.kernel.org/20260605161422.213817-8-npache@redhat.com Link: https://lore.kernel.org/lkml/20241216165105.56185-11-dev.jain@arm.com/ [1] Co-developed-by: Dev Jain <dev.jain@arm.com> Signed-off-by: Dev Jain <dev.jain@arm.com> Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand (arm) <david@kernel.org> Acked-by: Usama Arif <usama.arif@linux.dev> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Nico Pache
|
e22f2fe72c |
mm/khugepaged: generalize collapse_huge_page for mTHP collapse
Pass an order to collapse_huge_page to support collapsing anon memory to arbitrary orders within a PMD. order indicates what mTHP size we are attempting to collapse to. For non-PMD collapse we must leave the anon VMA write locked until after we collapse the mTHP-- in the PMD case all the pages are isolated, but in the mTHP case this is not true, and we must keep the lock to prevent access/changes to the page tables. This can happen if the rmap walkers hit a pmd_none while the PMD entry is currently unavailable due to being temporarily removed during the collapse phase. To properly establish the page table hierarchy without violating any expectations from certain architectures (e.g. MIPS), we must make sure to have the PMD reinstalled before the PTEs, and hold both PTE/PMD locks before calling update_mmu_cache_range() (if they are distinct locks). Link: https://lore.kernel.org/20260605161422.213817-7-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Nico Pache
|
da98790891 |
mm/khugepaged: require collapse_huge_page to enter/exit with the lock dropped
Currently the collapse_huge_page function requires the mmap_read_lock to enter with it held, and exit with it dropped. This function moves the unlock into its parent caller, and changes this semantic to requiring it to enter/exit with it always unlocked. In future patches, we need this expectation, as for in mTHP collapse, we may have already dropped the lock, and do not want to conditionally check for this by passing through the lock_dropped variable. No functional change is expected as one of the first things the collapse_huge_page function does is drop this lock before allocating the hugepage. Link: https://lore.kernel.org/20260605161422.213817-6-npache@redhat.com Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Rientjes <rientjes@google.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Takashi Iwai (SUSE) <tiwai@suse.de> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |