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260 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Dapeng Mi
|
8ba0b706a4 |
perf/x86/intel: Always reprogram ACR events to prevent stale masks
Members of an ACR group are logically linked via a bitmask of their
hardware counter indices. If some members of the group are assigned new
hardware counters during rescheduling, even events that keep their
original counter index must be updated with a new mask.
Without this, an event will continue to use a stale acr_mask that
references the old indices of its group peers. Ensure all ACR events are
reprogrammed during the scheduling path to maintain consistency across
the group.
Fixes:
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Peter Zijlstra
|
f1cac6ac62 |
x86/perf: Make sure to program the counter value for stopped events on migration
Both Mi Dapeng and Ian Rogers noted that not everything that sets HES_STOPPED
is required to EF_UPDATE. Specifically the 'step 1' loop of rescheduling
explicitly does EF_UPDATE to ensure the counter value is read.
However, then 'step 2' simply leaves the new counter uninitialized when
HES_STOPPED, even though, as noted above, the thing that stopped them might not
be aware it needs to EF_RELOAD -- since it didn't EF_UPDATE on stop.
One such location that is affected is throttling, throttle does pmu->stop(, 0);
and unthrottle does pmu->start(, 0); possibly restarting an uninitialized counter.
Fixes:
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Breno Leitao
|
8d5fae6011 |
perf/x86: Move event pointer setup earlier in x86_pmu_enable()
A production AMD EPYC system crashed with a NULL pointer dereference in the PMU NMI handler: BUG: kernel NULL pointer dereference, address: 0000000000000198 RIP: x86_perf_event_update+0xc/0xa0 Call Trace: <NMI> amd_pmu_v2_handle_irq+0x1a6/0x390 perf_event_nmi_handler+0x24/0x40 The faulting instruction is `cmpq $0x0, 0x198(%rdi)` with RDI=0, corresponding to the `if (unlikely(!hwc->event_base))` check in x86_perf_event_update() where hwc = &event->hw and event is NULL. drgn inspection of the vmcore on CPU 106 showed a mismatch between cpuc->active_mask and cpuc->events[]: active_mask: 0x1e (bits 1, 2, 3, 4) events[1]: 0xff1100136cbd4f38 (valid) events[2]: 0x0 (NULL, but active_mask bit 2 set) events[3]: 0xff1100076fd2cf38 (valid) events[4]: 0xff1100079e990a90 (valid) The event that should occupy events[2] was found in event_list[2] with hw.idx=2 and hw.state=0x0, confirming x86_pmu_start() had run (which clears hw.state and sets active_mask) but events[2] was never populated. Another event (event_list[0]) had hw.state=0x7 (STOPPED|UPTODATE|ARCH), showing it was stopped when the PMU rescheduled events, confirming the throttle-then-reschedule sequence occurred. The root cause is commit |
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Linus Torvalds
|
bf4afc53b7 |
Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kees Cook
|
69050f8d6d |
treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org> |
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Linus Torvalds
|
4d84667627 |
Performance events changes for v7.0:
x86 PMU driver updates:
- Add support for the core PMU for Intel Diamond Rapids (DMR) CPUs.
Compared to previous iterations of the Intel PMU code, there's
been a lot of changes, which center around three main areas:
- Introduce the OFF-MODULE RESPONSE (OMR) facility to
replace the Off-Core Response (OCR) facility
- New PEBS data source encoding layout
- Support the new "RDPMC user disable" feature
(Dapeng Mi)
- Likewise, a large series adds uncore PMU support for
Intel Diamond Rapids (DMR) CPUs, which center around these
four main areas:
- DMR may have two Integrated I/O and Memory Hub (IMH) dies,
separate from the compute tile (CBB) dies. Each CBB and
each IMH die has its own discovery domain.
- Unlike prior CPUs that retrieve the global discovery table
portal exclusively via PCI or MSR, DMR uses PCI for IMH PMON
discovery and MSR for CBB PMON discovery.
- DMR introduces several new PMON types: SCA, HAMVF, D2D_ULA,
UBR, PCIE4, CRS, CPC, ITC, OTC, CMS, and PCIE6.
- IIO free-running counters in DMR are MMIO-based, unlike SPR.
(Zide Chen)
- Also add support for Add missing PMON units for Intel Panther Lake,
and support Nova Lake (NVL), which largely maps to Panther Lake.
(Zide Chen)
- KVM integration: Add support for mediated vPMUs (by Kan Liang
and Sean Christopherson, with fixes and cleanups by Peter Zijlstra,
Sandipan Das and Mingwei Zhang)
- Add Intel cstate driver to support for Wildcat Lake (WCL)
CPUs, which are a low-power variant of Panther Lake.
(Zide Chen)
- Add core, cstate and MSR PMU support for the Airmont NP Intel CPU
(aka MaxLinear Lightning Mountain), which maps to the existing
Airmont code. (Martin Schiller)
Performance enhancements:
- core: Speed up kexec shutdown by avoiding unnecessary
cross CPU calls. (Jan H. Schönherr)
- core: Fix slow perf_event_task_exit() with LBR callstacks
(Namhyung Kim)
User-space stack unwinding support:
- Various cleanups and refactorings in preparation to generalize
the unwinding code for other architectures. (Jens Remus)
Uprobes updates:
- Transition from kmap_atomic to kmap_local_page (Keke Ming)
- Fix incorrect lockdep condition in filter_chain() (Breno Leitao)
- Fix XOL allocation failure for 32-bit tasks (Oleg Nesterov)
Misc fixes and cleanups:
- s390: Remove kvm_types.h from Kbuild (Randy Dunlap)
- x86/intel/uncore: Convert comma to semicolon (Chen Ni)
- x86/uncore: Clean up const mismatch (Greg Kroah-Hartman)
- x86/ibs: Fix typo in dc_l2tlb_miss comment (Xiang-Bin Shi)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance event updates from Ingo Molnar:
"x86 PMU driver updates:
- Add support for the core PMU for Intel Diamond Rapids (DMR) CPUs
(Dapeng Mi)
Compared to previous iterations of the Intel PMU code, there's been
a lot of changes, which center around three main areas:
- Introduce the OFF-MODULE RESPONSE (OMR) facility to replace the
Off-Core Response (OCR) facility
- New PEBS data source encoding layout
- Support the new "RDPMC user disable" feature
- Likewise, a large series adds uncore PMU support for Intel Diamond
Rapids (DMR) CPUs (Zide Chen)
This centers around these four main areas:
- DMR may have two Integrated I/O and Memory Hub (IMH) dies,
separate from the compute tile (CBB) dies. Each CBB and each IMH
die has its own discovery domain.
- Unlike prior CPUs that retrieve the global discovery table
portal exclusively via PCI or MSR, DMR uses PCI for IMH PMON
discovery and MSR for CBB PMON discovery.
- DMR introduces several new PMON types: SCA, HAMVF, D2D_ULA, UBR,
PCIE4, CRS, CPC, ITC, OTC, CMS, and PCIE6.
- IIO free-running counters in DMR are MMIO-based, unlike SPR.
- Also add support for Add missing PMON units for Intel Panther Lake,
and support Nova Lake (NVL), which largely maps to Panther Lake.
(Zide Chen)
- KVM integration: Add support for mediated vPMUs (by Kan Liang and
Sean Christopherson, with fixes and cleanups by Peter Zijlstra,
Sandipan Das and Mingwei Zhang)
- Add Intel cstate driver to support for Wildcat Lake (WCL) CPUs,
which are a low-power variant of Panther Lake (Zide Chen)
- Add core, cstate and MSR PMU support for the Airmont NP Intel CPU
(aka MaxLinear Lightning Mountain), which maps to the existing
Airmont code (Martin Schiller)
Performance enhancements:
- Speed up kexec shutdown by avoiding unnecessary cross CPU calls
(Jan H. Schönherr)
- Fix slow perf_event_task_exit() with LBR callstacks (Namhyung Kim)
User-space stack unwinding support:
- Various cleanups and refactorings in preparation to generalize the
unwinding code for other architectures (Jens Remus)
Uprobes updates:
- Transition from kmap_atomic to kmap_local_page (Keke Ming)
- Fix incorrect lockdep condition in filter_chain() (Breno Leitao)
- Fix XOL allocation failure for 32-bit tasks (Oleg Nesterov)
Misc fixes and cleanups:
- s390: Remove kvm_types.h from Kbuild (Randy Dunlap)
- x86/intel/uncore: Convert comma to semicolon (Chen Ni)
- x86/uncore: Clean up const mismatch (Greg Kroah-Hartman)
- x86/ibs: Fix typo in dc_l2tlb_miss comment (Xiang-Bin Shi)"
* tag 'perf-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
s390: remove kvm_types.h from Kbuild
uprobes: Fix incorrect lockdep condition in filter_chain()
x86/ibs: Fix typo in dc_l2tlb_miss comment
x86/uprobes: Fix XOL allocation failure for 32-bit tasks
perf/x86/intel/uncore: Convert comma to semicolon
perf/x86/intel: Add support for rdpmc user disable feature
perf/x86: Use macros to replace magic numbers in attr_rdpmc
perf/x86/intel: Add core PMU support for Novalake
perf/x86/intel: Add support for PEBS memory auxiliary info field in NVL
perf/x86/intel: Add core PMU support for DMR
perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR
perf/x86/intel: Support the 4 new OMR MSRs introduced in DMR and NVL
perf/core: Fix slow perf_event_task_exit() with LBR callstacks
perf/core: Speed up kexec shutdown by avoiding unnecessary cross CPU calls
uprobes: use kmap_local_page() for temporary page mappings
arm/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
mips/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
arm64/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
riscv/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
perf/x86/intel/uncore: Add Nova Lake support
...
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Dapeng Mi
|
59af95e028 |
perf/x86/intel: Add support for rdpmc user disable feature
Starting with Panther Cove, the rdpmc user disable feature is supported. This feature allows the perf system to disable user space rdpmc reads at the counter level. Currently, when a global counter is active, any user with rdpmc rights can read it, even if perf access permissions forbid it (e.g., disallow reading ring 0 counters). The rdpmc user disable feature mitigates this security concern. Details: - A new RDPMC_USR_DISABLE bit (bit 37) in each EVNTSELx MSR indicates that the GP counter cannot be read by RDPMC in ring 3. - New RDPMC_USR_DISABLE bits in IA32_FIXED_CTR_CTRL MSR (bits 33, 37, 41, 45, etc.) for fixed counters 0, 1, 2, 3, etc. - When calling rdpmc instruction for counter x, the following pseudo code demonstrates how the counter value is obtained: If (!CPL0 && RDPMC_USR_DISABLE[x] == 1) ? 0 : counter_value; - RDPMC_USR_DISABLE is enumerated by CPUID.0x23.0.EBX[2]. This patch extends the current global user space rdpmc control logic via the sysfs interface (/sys/devices/cpu/rdpmc) as follows: - rdpmc = 0: Global user space rdpmc and counter-level user space rdpmc for all counters are both disabled. - rdpmc = 1: Global user space rdpmc is enabled during the mmap-enabled time window, and counter-level user space rdpmc is enabled only for non-system-wide events. This prevents counter data leaks as count data is cleared during context switches. - rdpmc = 2: Global user space rdpmc and counter-level user space rdpmc for all counters are enabled unconditionally. The new rdpmc settings only affect newly activated perf events; currently active perf events remain unaffected. This simplifies and cleans up the code. The default value of rdpmc remains unchanged at 1. For more details about rdpmc user disable, please refer to chapter 15 "RDPMC USER DISABLE" in ISE documentation. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260114011750.350569-8-dapeng1.mi@linux.intel.com |
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Dapeng Mi
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8c74e4e3e0 |
perf/x86: Use macros to replace magic numbers in attr_rdpmc
Replace magic numbers in attr_rdpmc with macros to improve readability and make their meanings clearer for users. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260114011750.350569-7-dapeng1.mi@linux.intel.com |
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Thomas Gleixner
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2e4b28c48f |
treewide: Update email address
In a vain attempt to consolidate the email zoo switch everything to the kernel.org account. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Peter Zijlstra
|
01122b8936 |
perf: Use EXPORT_SYMBOL_FOR_KVM() for the mediated APIs
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251208115156.GE3707891@noisy.programming.kicks-ass.net |
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Mingwei Zhang
|
c8824a95d9 |
perf/x86/core: Plumb mediated PMU capability from x86_pmu to x86_pmu_cap
Plumb mediated PMU capability to x86_pmu_cap in order to let any kernel entity such as KVM know that host PMU support mediated PMU mode and has the implementation. Signed-off-by: Mingwei Zhang <mizhang@google.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Xudong Hao <xudong.hao@intel.com> Link: https://patch.msgid.link/20251206001720.468579-12-seanjc@google.com |
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Sandipan Das
|
b456a6ba57 |
perf/x86/core: Do not set bit width for unavailable counters
Not all x86 processors have fixed counters. It may also be the case that
a processor has only fixed counters and no general-purpose counters. Set
the bit widths corresponding to each counter type only if such counters
are available.
Fixes:
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Sean Christopherson
|
560ac136f2 |
perf/x86/core: Add APIs to switch to/from mediated PMI vector (for KVM)
Add APIs (exported only for KVM) to switch PMIs to the dedicated mediated PMU IRQ vector when loading guest context, and back to perf's standard NMI when the guest context is put. I.e. route PMIs to PERF_GUEST_MEDIATED_PMI_VECTOR when the guest context is active, and to NMIs while the host context is active. While running with guest context loaded, ignore all NMIs (in perf). Any NMI that arrives while the LVTPC points at the mediated PMU IRQ vector can't possibly be due to a host perf event. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251206001720.468579-10-seanjc@google.com |
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Linus Torvalds
|
e2aa39b368 |
* Make MSR-induced taint easier for users to track down
* Restrict KVM-specific exports to KVM itself -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmkuHIIACgkQaDWVMHDJ krAxMg//RQUz6JnQnMASuN/NhrjIANRjcPJI9S0LoKcTbZ0nZ5aH6oR1VOFszLLa ShGcUO2RuDbCl2wPAG/lRWV8eL/4k4mZi0zNT7vEKTkX/EZn5RDV59p88zCo62KV 835OpX8W9Hvyiichw51RoVrJxEcqgCmlUYO2fCwtk2rpntUCOVQgHMeLhhqMsZ0e yMQECAE75oXQ4vhAG+zO7/KmLqVbSGgqpXYw6DOZGEJF0T7tdZIgFhd25WAPgcf0 UN8VmTX971Eq67OrUX9OojN6+SxBqQ7vc+qBtd5bDlkZsRxVyV157Zso2PCPbsm2 FkE65eJBa9qacqvwkCPND6J7gvE/Sm8DaLVafLPKDNWTaqSo4cfKJD7P/sgN1L69 O8QsiLfafy8ITIA8AXS90C8x/puhqk15OKW2kJFFfUkhrGdu72/AxVlo6JcM1N0u qkDXUNBSX9/LHkRT9AtkLch27MEFXRKxsajjx2lFoBIR2VjIijm9314cRczHGZEV R/pqBh21yL/ZTriNIgmEPrFOV4zDxaOsHRh8YSEFAXRe2xWvm7dZwNSPRSh7hMT+ q0ABPuYqTZ4PDGMaAB0gNRqmR9aQKpVMY+4xmTdmqscYkgV4usZQcrQOeiKVwh7F KdMC5tr4yFOMMl8CaMgOK+27ZrSYI1hwtXCc/orAhOwxhg62Z40= =tjcN -----END PGP SIGNATURE----- Merge tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 updates from Dave Hansen: "The most significant are some changes to ensure that symbols exported for KVM are used only by KVM modules themselves, along with some related cleanups. In true x86/misc fashion, the other patch is completely unrelated and just enhances an existing pr_warn() to make it clear to users how they have tainted their kernel when something is mucking with MSRs. Summary: - Make MSR-induced taint easier for users to track down - Restrict KVM-specific exports to KVM itself" * tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible x86/mm: Drop unnecessary export of "ptdump_walk_pgd_level_debugfs" x86/mtrr: Drop unnecessary export of "mtrr_state" x86/bugs: Drop unnecessary export of "x86_spec_ctrl_base" x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg) |
||
|
Linus Torvalds
|
6c26fbe8c9 |
Performance events changes for v6.19:
Callchain support:
- Add support for deferred user-space stack unwinding for
perf, enabled on x86. (Peter Zijlstra, Steven Rostedt)
- unwind_user/x86: Enable frame pointer unwinding on x86
(Josh Poimboeuf)
x86 PMU support and infrastructure:
- x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)
- x86/insn,uprobes,alternative: Unify insn_is_nop()
(Peter Zijlstra)
Intel PMU driver:
- Large series to prepare for and implement architectural PEBS
support for Intel platforms such as Clearwater Forest (CWF)
and Panther Lake (PTL). (Dapeng Mi, Kan Liang)
- Check dynamic constraints (Kan Liang)
- Optimize PEBS extended config (Peter Zijlstra)
- cstates: Remove PC3 support from LunarLake (Zhang Rui)
- cstates: Add Pantherlake support (Zhang Rui)
- cstates: Clearwater Forest support (Zide Chen)
AMD PMU driver:
- x86/amd: Check event before enable to avoid GPF (George Kennedy)
Fixes and cleanups:
- task_work: Fix NMI race condition (Peter Zijlstra)
- perf/x86: Fix NULL event access and potential PEBS record loss
(Dapeng Mi)
- Misc other fixes and cleanups.
(Dapeng Mi, Ingo Molnar, Peter Zijlstra)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"Callchain support:
- Add support for deferred user-space stack unwinding for perf,
enabled on x86. (Peter Zijlstra, Steven Rostedt)
- unwind_user/x86: Enable frame pointer unwinding on x86 (Josh
Poimboeuf)
x86 PMU support and infrastructure:
- x86/insn: Simplify for_each_insn_prefix() (Peter Zijlstra)
- x86/insn,uprobes,alternative: Unify insn_is_nop() (Peter Zijlstra)
Intel PMU driver:
- Large series to prepare for and implement architectural PEBS
support for Intel platforms such as Clearwater Forest (CWF) and
Panther Lake (PTL). (Dapeng Mi, Kan Liang)
- Check dynamic constraints (Kan Liang)
- Optimize PEBS extended config (Peter Zijlstra)
- cstates:
- Remove PC3 support from LunarLake (Zhang Rui)
- Add Pantherlake support (Zhang Rui)
- Clearwater Forest support (Zide Chen)
AMD PMU driver:
- x86/amd: Check event before enable to avoid GPF (George Kennedy)
Fixes and cleanups:
- task_work: Fix NMI race condition (Peter Zijlstra)
- perf/x86: Fix NULL event access and potential PEBS record loss
(Dapeng Mi)
- Misc other fixes and cleanups (Dapeng Mi, Ingo Molnar, Peter
Zijlstra)"
* tag 'perf-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
perf/x86/intel: Fix and clean up intel_pmu_drain_arch_pebs() type use
perf/x86/intel: Optimize PEBS extended config
perf/x86/intel: Check PEBS dyn_constraints
perf/x86/intel: Add a check for dynamic constraints
perf/x86/intel: Add counter group support for arch-PEBS
perf/x86/intel: Setup PEBS data configuration and enable legacy groups
perf/x86/intel: Update dyn_constraint base on PEBS event precise level
perf/x86/intel: Allocate arch-PEBS buffer and initialize PEBS_BASE MSR
perf/x86/intel: Process arch-PEBS records or record fragments
perf/x86/intel/ds: Factor out PEBS group processing code to functions
perf/x86/intel/ds: Factor out PEBS record processing code to functions
perf/x86/intel: Initialize architectural PEBS
perf/x86/intel: Correct large PEBS flag check
perf/x86/intel: Replace x86_pmu.drain_pebs calling with static call
perf/x86: Fix NULL event access and potential PEBS record loss
perf/x86: Remove redundant is_x86_event() prototype
entry,unwind/deferred: Fix unwind_reset_info() placement
unwind_user/x86: Fix arch=um build
perf: Support deferred user unwind
unwind_user/x86: Teach FP unwind about start of function
...
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Sean Christopherson
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6276c67f2b |
x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible
Extend KVM's export macro framework to provide EXPORT_SYMBOL_FOR_KVM(), and use the helper macro to export symbols for KVM throughout x86 if and only if KVM will build one or more modules, and only for those modules. To avoid unnecessary exports when CONFIG_KVM=m but kvm.ko will not be built (because no vendor modules are selected), let arch code #define EXPORT_SYMBOL_FOR_KVM to suppress/override the exports. Note, the set of symbols to restrict to KVM was generated by manual search and audit; any "misses" are due to human error, not some grand plan. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kai Huang <kai.huang@intel.com> Tested-by: Kai Huang <kai.huang@intel.com> Link: https://patch.msgid.link/20251112173944.1380633-5-seanjc%40google.com |
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Dapeng Mi
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d243d0bb64 |
perf/x86/intel: Initialize architectural PEBS
arch-PEBS leverages CPUID.23H.4/5 sub-leaves enumerate arch-PEBS supported capabilities and counters bitmap. This patch parses these 2 sub-leaves and initializes arch-PEBS capabilities and corresponding structures. Since IA32_PEBS_ENABLE and MSR_PEBS_DATA_CFG MSRs are no longer existed for arch-PEBS, arch-PEBS doesn't need to manipulate these MSRs. Thus add a simple pair of __intel_pmu_pebs_enable/disable() callbacks for arch-PEBS. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251029102136.61364-6-dapeng1.mi@linux.intel.com |
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Dapeng Mi
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7e772a93eb |
perf/x86: Fix NULL event access and potential PEBS record loss
When intel_pmu_drain_pebs_icl() is called to drain PEBS records, the
perf_event_overflow() could be called to process the last PEBS record.
While perf_event_overflow() could trigger the interrupt throttle and
stop all events of the group, like what the below call-chain shows.
perf_event_overflow()
-> __perf_event_overflow()
->__perf_event_account_interrupt()
-> perf_event_throttle_group()
-> perf_event_throttle()
-> event->pmu->stop()
-> x86_pmu_stop()
The side effect of stopping the events is that all corresponding event
pointers in cpuc->events[] array are cleared to NULL.
Assume there are two PEBS events (event a and event b) in a group. When
intel_pmu_drain_pebs_icl() calls perf_event_overflow() to process the
last PEBS record of PEBS event a, interrupt throttle is triggered and
all pointers of event a and event b are cleared to NULL. Then
intel_pmu_drain_pebs_icl() tries to process the last PEBS record of
event b and encounters NULL pointer access.
To avoid this issue, move cpuc->events[] clearing from x86_pmu_stop()
to x86_pmu_del(). It's safe since cpuc->active_mask or
cpuc->pebs_enabled is always checked before access the event pointer
from cpuc->events[].
Closes: https://lore.kernel.org/oe-lkp/202507042103.a15d2923-lkp@intel.com
Fixes:
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Jiri Olsa
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6d08340d1e |
Revert "perf/x86: Always store regs->ip in perf_callchain_kernel()"
This reverts commit
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Peter Zijlstra
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ae25884ad7 |
unwind_user/x86: Teach FP unwind about start of function
When userspace is interrupted at the start of a function, before we get a chance to complete the frame, unwind will miss one caller. X86 has a uprobe specific fixup for this, add bits to the generic unwinder to support this. Suggested-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251024145156.GM4068168@noisy.programming.kicks-ass.net |
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Dapeng Mi
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f49e1be195 |
perf/x86: Print PMU counters bitmap in x86_pmu_show_pmu_cap()
Along with the introduction Perfmon v6, pmu counters could be incontinuous, like fixed counters on CWF, only fixed counters 0-3 and 5-7 are supported, there is no fixed counter 4 on CWF. To accommodate this change, archPerfmonExt CPUID (0x23) leaves are introduced to enumerate the true-view of counters bitmap. Current perf code already supports archPerfmonExt CPUID and uses counters-bitmap to enumerate HW really supported counters, but x86_pmu_show_pmu_cap() still only dumps the absolute counter number instead of true-view bitmap, it's out-dated and may mislead readers. So dump counters true-view bitmap in x86_pmu_show_pmu_cap() and opportunistically change the dump sequence and words. Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20250820023032.17128-8-dapeng1.mi@linux.intel.com |
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Linus Torvalds
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785cdec46e |
Core x86 updates for v6.16:
Boot code changes:
- A large series of changes to reorganize the x86 boot code into a better isolated
and easier to maintain base of PIC early startup code in arch/x86/boot/startup/,
by Ard Biesheuvel.
Motivation & background:
| Since commit
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Kan Liang
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b8328f6720 |
perf/x86/intel: Remove driver-specific throttle support
The throttle support has been added in the generic code. Remove the driver-specific throttle support. Besides the throttle, perf_event_overflow may return true because of event_limit. It already does an inatomic event disable. The pmu->stop is not required either. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250520181644.2673067-4-kan.liang@linux.intel.com |
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Ingo Molnar
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1f82e8e1ca |
Merge branch 'x86/msr' into x86/core, to resolve conflicts
Conflicts: arch/x86/boot/startup/sme.c arch/x86/coco/sev/core.c arch/x86/kernel/fpu/core.c arch/x86/kernel/fpu/xstate.c Semantic conflict: arch/x86/include/asm/sev-internal.h Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Ingo Molnar
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11d8f542d9 |
Merge branch 'x86/alternatives' into x86/core, to merge dependent commits
Prepare to resolve conflicts with an upstream series of fixes that conflict
with pending x86 changes:
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Ingo Molnar
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570d58b12f |
Linux 6.15-rc5
-----BEGIN PGP SIGNATURE----- iQFSBAABCgA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmgX1CgeHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGxiIH/A7LHlVatGEQgRFi 0JALDgcuGTMtMU1qD43rv8Z1GXqTpCAlaBt9D1C9cUH/86MGyBTVRWgVy0wkaU2U 8QSfFWQIbrdaIzelHtzmAv5IDtb+KrcX1iYGLcMb6ZYaWkv8/CMzMX1nkgxEr1QT 37Xo3/F17yJumAdNQxdRhVLGy2d3X5rScecpufwh97sMwoddllMCDs2LIoeSAYpG 376/wzni09G2fADa8MEKqcaMue4qcf0FOo/gOkT8YwFGSZLKa6uumlBLg04QoCt0 foK2vfcci1q4H4ZbCu3uQESYGLQHY0f2ICDCwC3m25VF9a81TmlbC3MLum3vhmKe RtLDcXg= =xyaI -----END PGP SIGNATURE----- Merge tag 'v6.15-rc5' into x86/msr, to pick up fixes and to resolve conflicts Conflicts: drivers/cpufreq/intel_pstate.c Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Xin Li (Intel)
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795ada5287 |
x86/msr: Convert the rdpmc() macro to an __always_inline function
Functions offer type safety and better readability compared to macros. Additionally, always inline functions can match the performance of macros. Converting the rdpmc() macro into an always inline function is simple and straightforward, so just make the change. Moreover, the read result is now the returned value, further enhancing readability. Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250427092027.1598740-6-xin@zytor.com |
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Xin Li (Intel)
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7d9ccde56b |
x86/msr: Rename rdpmcl() to rdpmc()
Now that rdpmc() is gone, rdpmcl() is the sole PMC read helper, simply rename rdpmcl() to rdpmc(). Signed-off-by: Xin Li (Intel) <xin@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Uros Bizjak <ubizjak@gmail.com> Link: https://lore.kernel.org/r/20250427092027.1598740-5-xin@zytor.com |
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Xin Li (Intel)
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efef7f184f |
x86/msr: Add explicit includes of <asm/msr.h>
For historic reasons there are some TSC-related functions in the
<asm/msr.h> header, even though there's an <asm/tsc.h> header.
To facilitate the relocation of rdtsc{,_ordered}() from <asm/msr.h>
to <asm/tsc.h> and to eventually eliminate the inclusion of
<asm/msr.h> in <asm/tsc.h>, add an explicit <asm/msr.h> dependency
to the source files that reference definitions from <asm/msr.h>.
[ mingo: Clarified the changelog. ]
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Link: https://lore.kernel.org/r/20250501054241.1245648-1-xin@zytor.com
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Ingo Molnar
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0c7b20b852 |
Linux 6.15-rc4
-----BEGIN PGP SIGNATURE----- iQFSBAABCgA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmgOrWseHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGFyIH/AhXcuA8y8rk43mo t+0GO7JR4dnr4DIl74GgDjCXlXiKCT7EXMfD/ABdofTxV4Pbyv+pUODlg1E6eO9U C1WWM5PPNBGDDEVSQ3Yu756nr0UoiFhvW0R6pVdou5cezCWAtIF9LTN8DEUgis0u EUJD9+/cHAMzfkZwabjm/HNsa1SXv2X47MzYv/PdHKr0htEPcNHF4gqBrBRdACGy FJtaCKhuPf6TcDNXOFi5IEWMXrugReRQmOvrXqVYGa7rfUFkZgsAzRY6n/rUN5Z9 FAgle4Vlv9ohVYj9bXX8b6wWgqiKRpoN+t0PpRd6G6ict1AFBobNGo8LH3tYIKqZ b/dCGNg= =xDGd -----END PGP SIGNATURE----- Merge tag 'v6.15-rc4' into x86/msr, to pick up fixes and resolve conflicts Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Kan Liang
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3e830f657f |
perf/x86: Optimize the is_x86_event
The current is_x86_event has to go through the hybrid_pmus list to find the matched pmu, then check if it's a X86 PMU and a X86 event. It's not necessary. The X86 PMU has a unique type ID on a non-hybrid machine, and a unique capability type. They are good enough to do the check. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20250424134718.311934-5-kan.liang@linux.intel.com |
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Peter Zijlstra
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1caafd919e |
Merge branch 'perf/urgent'
Merge urgent fixes for dependencies. Signed-off-by: Peter Zijlstra <peterz@infradead.org> |
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Kan Liang
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75aea4b065 |
perf/x86/intel: Only check the group flag for X86 leader
A warning in intel_pmu_lbr_counters_reorder() may be triggered by below
perf command.
perf record -e "{cpu-clock,cycles/call-graph="lbr"/}" -- sleep 1
It's because the group is mistakenly treated as a branch counter group.
The hw.flags of the leader are used to determine whether a group is a
branch counters group. However, the hw.flags is only available for a
hardware event. The field to store the flags is a union type. For a
software event, it's a hrtimer. The corresponding bit may be set if the
leader is a software event.
For a branch counter group and other groups that have a group flag
(e.g., topdown, PEBS counters snapshotting, and ACR), the leader must
be a X86 event. Check the X86 event before checking the flag.
The patch only fixes the issue for the branch counter group.
The following patch will fix the other groups.
There may be an alternative way to fix the issue by moving the hw.flags
out of the union type. It should work for now. But it's still possible
that the flags will be used by other types of events later. As long as
that type of event is used as a leader, a similar issue will be
triggered. So the alternative way is dropped.
Fixes:
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Luo Gengkun
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1a97fea9db |
perf/x86: Fix non-sampling (counting) events on certain x86 platforms
Perf doesn't work at perf stat for hardware events on certain x86 platforms:
$perf stat -- sleep 1
Performance counter stats for 'sleep 1':
16.44 msec task-clock # 0.016 CPUs utilized
2 context-switches # 121.691 /sec
0 cpu-migrations # 0.000 /sec
54 page-faults # 3.286 K/sec
<not supported> cycles
<not supported> instructions
<not supported> branches
<not supported> branch-misses
The reason is that the check in x86_pmu_hw_config() for sampling events is
unexpectedly applied to counting events as well.
It should only impact x86 platforms with limit_period used for non-PEBS
events. For Intel platforms, it should only impact some older platforms,
e.g., HSW, BDW and NHM.
Fixes:
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Dapeng Mi
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4a3fd13054 |
perf/x86/intel: Introduce pairs of PEBS static calls
Arch-PEBS retires IA32_PEBS_ENABLE and MSR_PEBS_DATA_CFG MSRs, so intel_pmu_pebs_enable/disable() and intel_pmu_pebs_enable/disable_all() are not needed to call for ach-PEBS. To make the code cleaner, introduce static calls x86_pmu_pebs_enable/disable() and x86_pmu_pebs_enable/disable_all() instead of adding "x86_pmu.arch_pebs" check directly in these helpers. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20250415114428.341182-7-dapeng1.mi@linux.intel.com |
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Andy Lutomirski
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81e3cbdef2 |
x86/events, x86/insn-eval: Remove incorrect current->active_mm references
When decoding an instruction or handling a perf event that references an LDT segment, if we don't have a valid user context, trying to access the LDT by any means other than SLDT is racy. Certainly, using current->active_mm is wrong, as active_mm can point to a real user mm when CR3 and LDTR no longer reference that mm. Clean up the code. If nmi_uaccess_okay() says we don't have a valid context, just fail. Otherwise use current->mm. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20250402094540.3586683-3-mingo@kernel.org |
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Ingo Molnar
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6fa17efe45 |
x86/msr: Rename 'wrmsrl_safe()' to 'wrmsrq_safe()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Xin Li <xin@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar
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6fe22abacd |
x86/msr: Rename 'rdmsrl_safe()' to 'rdmsrq_safe()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Xin Li <xin@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar
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78255eb239 |
x86/msr: Rename 'wrmsrl()' to 'wrmsrq()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Xin Li <xin@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> |
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Ingo Molnar
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c435e608cf |
x86/msr: Rename 'rdmsrl()' to 'rdmsrq()'
Suggested-by: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juergen Gross <jgross@suse.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Xin Li <xin@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> |
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Mark Barnett
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1734d98fbc |
perf/arch: Record sample last_period before updating on the x86 and PowerPC platforms
This change alters the PowerPC and x86 driver implementations to record the last sample period before the event is updated for the next period. A common pattern in PMU driver implementations is to have a "*_event_set_period" function which takes care of updating the various period-related fields in a perf_event structure. In most cases, the drivers choose to call this function after initializing a sample data structure with perf_sample_data_init. The x86 and PowerPC drivers deviate from this, choosing to update the period before initializing the sample data. When using an event with an alternate sample period, this causes an incorrect period to be written to the sample data that gets reported to userspace. Signed-off-by: Mark Barnett <mark.barnett@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250408171530.140858-2-mark.barnett@arm.com |
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Kan Liang
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ec980e4fac |
perf/x86/intel: Support auto counter reload
The relative rates among two or more events are useful for performance
analysis, e.g., a high branch miss rate may indicate a performance
issue. Usually, the samples with a relative rate that exceeds some
threshold are more useful. However, the traditional sampling takes
samples of events separately. To get the relative rates among two or
more events, a high sample rate is required, which can bring high
overhead. Many samples taken in the non-hotspot area are also dropped
(useless) in the post-process.
The auto counter reload (ACR) feature takes samples when the relative
rate of two or more events exceeds some threshold, which provides the
fine-grained information at a low cost.
To support the feature, two sets of MSRs are introduced. For a given
counter IA32_PMC_GPn_CTR/IA32_PMC_FXm_CTR, bit fields in the
IA32_PMC_GPn_CFG_B/IA32_PMC_FXm_CFG_B MSR indicate which counter(s)
can cause a reload of that counter. The reload value is stored in the
IA32_PMC_GPn_CFG_C/IA32_PMC_FXm_CFG_C.
The details can be found at Intel SDM (085), Volume 3, 21.9.11 Auto
Counter Reload.
In the hw_config(), an ACR event is specially configured, because the
cause/reloadable counter mask has to be applied to the dyn_constraint.
Besides the HW limit, e.g., not support perf metrics, PDist and etc, a
SW limit is applied as well. ACR events in a group must be contiguous.
It facilitates the later conversion from the event idx to the counter
idx. Otherwise, the intel_pmu_acr_late_setup() has to traverse the whole
event list again to find the "cause" event.
Also, add a new flag PERF_X86_EVENT_ACR to indicate an ACR group, which
is set to the group leader.
The late setup() is also required for an ACR group. It's to convert the
event idx to the counter idx, and saved it in hw.config1.
The ACR configuration MSRs are only updated in the enable_event().
The disable_event() doesn't clear the ACR CFG register.
Add acr_cfg_b/acr_cfg_c in the struct cpu_hw_events to cache the MSR
values. It can avoid a MSR write if the value is not changed.
Expose an acr_mask to the sysfs. The perf tool can utilize the new
format to configure the relation of events in the group. The bit
sequence of the acr_mask follows the events enabled order of the group.
Example:
Here is the snippet of the mispredict.c. Since the array has a random
numbers, jumps are random and often mispredicted.
The mispredicted rate depends on the compared value.
For the Loop1, ~11% of all branches are mispredicted.
For the Loop2, ~21% of all branches are mispredicted.
main()
{
...
for (i = 0; i < N; i++)
data[i] = rand() % 256;
...
/* Loop 1 */
for (k = 0; k < 50; k++)
for (i = 0; i < N; i++)
if (data[i] >= 64)
sum += data[i];
...
...
/* Loop 2 */
for (k = 0; k < 50; k++)
for (i = 0; i < N; i++)
if (data[i] >= 128)
sum += data[i];
...
}
Usually, a code with a high branch miss rate means a bad performance.
To understand the branch miss rate of the codes, the traditional method
usually samples both branches and branch-misses events. E.g.,
perf record -e "{cpu_atom/branch-misses/ppu, cpu_atom/branch-instructions/u}"
-c 1000000 -- ./mispredict
[ perf record: Woken up 4 times to write data ]
[ perf record: Captured and wrote 0.925 MB perf.data (5106 samples) ]
The 5106 samples are from both events and spread in both Loops.
In the post-process stage, a user can know that the Loop 2 has a 21%
branch miss rate. Then they can focus on the samples of branch-misses
events for the Loop 2.
With this patch, the user can generate the samples only when the branch
miss rate > 20%. For example,
perf record -e "{cpu_atom/branch-misses,period=200000,acr_mask=0x2/ppu,
cpu_atom/branch-instructions,period=1000000,acr_mask=0x3/u}"
-- ./mispredict
(Two different periods are applied to branch-misses and
branch-instructions. The ratio is set to 20%.
If the branch-instructions is overflowed first, the branch-miss
rate < 20%. No samples should be generated. All counters should be
automatically reloaded.
If the branch-misses is overflowed first, the branch-miss rate > 20%.
A sample triggered by the branch-misses event should be
generated. Just the counter of the branch-instructions should be
automatically reloaded.
The branch-misses event should only be automatically reloaded when
the branch-instructions is overflowed. So the "cause" event is the
branch-instructions event. The acr_mask is set to 0x2, since the
event index in the group of branch-instructions is 1.
The branch-instructions event is automatically reloaded no matter which
events are overflowed. So the "cause" events are the branch-misses
and the branch-instructions event. The acr_mask should be set to 0x3.)
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.098 MB perf.data (2498 samples) ]
$perf report
Percent │154: movl $0x0,-0x14(%rbp)
│ ↓ jmp 1af
│ for (i = j; i < N; i++)
│15d: mov -0x10(%rbp),%eax
│ mov %eax,-0x18(%rbp)
│ ↓ jmp 1a2
│ if (data[i] >= 128)
│165: mov -0x18(%rbp),%eax
│ cltq
│ lea 0x0(,%rax,4),%rdx
│ mov -0x8(%rbp),%rax
│ add %rdx,%rax
│ mov (%rax),%eax
│ ┌──cmp $0x7f,%eax
100.00 0.00 │ ├──jle 19e
│ │sum += data[i];
The 2498 samples are all from the branch-misses events for the Loop 2.
The number of samples and overhead is significantly reduced without
losing any information.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Thomas Falcon <thomas.falcon@intel.com>
Link: https://lkml.kernel.org/r/20250327195217.2683619-6-kan.liang@linux.intel.com
|
||
|
Kan Liang
|
4dfe3232cc |
perf/x86: Add dynamic constraint
More and more features require a dynamic event constraint, e.g., branch counter logging, auto counter reload, Arch PEBS, etc. Add a generic flag, PMU_FL_DYN_CONSTRAINT, to indicate the case. It avoids keeping adding the individual flag in intel_cpuc_prepare(). Add a variable dyn_constraint in the struct hw_perf_event to track the dynamic constraint of the event. Apply it if it's updated. Apply the generic dynamic constraint for branch counter logging. Many features on and after V6 require dynamic constraint. So unconditionally set the flag for V6+. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Thomas Falcon <thomas.falcon@intel.com> Link: https://lkml.kernel.org/r/20250327195217.2683619-2-kan.liang@linux.intel.com |
||
|
Linus Torvalds
|
e34c38057a |
[ Merge note: this pull request depends on you having merged
two locking commits in the locking tree,
part of the locking-core-2025-03-22 pull request. ]
x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid='
(Brendan Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and
related cleanups (Brian Gerst)
- Convert the stackprotector canary to a regular percpu
variable (Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB instruction
(Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation
(Kirill A. Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems,
to support PCI BAR space beyond the 10TiB region
(CONFIG_PCI_P2PDMA=y) (Balbir Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Bootup:
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0
(Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers
(Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
(Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking instructions
(Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()
(Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel,
Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst,
Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin,
Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport,
Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker,
Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra,
Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak,
Vitaly Kuznetsov, Xin Li, liuye.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
"x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and related cleanups
(Brian Gerst)
- Convert the stackprotector canary to a regular percpu variable
(Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB
instruction (Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation (Kirill A.
Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan
Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
headers (Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh
Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from
<asm/asm.h> (Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking
instructions (Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in
nmi_shootdown_cpus() (Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
Kuznetsov, Xin Li, liuye"
* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
x86/asm: Make asm export of __ref_stack_chk_guard unconditional
x86/mm: Only do broadcast flush from reclaim if pages were unmapped
perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
x86/asm: Use asm_inline() instead of asm() in clwb()
x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
x86/hweight: Use asm_inline() instead of asm()
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
x86/hweight: Use named operands in inline asm()
x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
x86/head/64: Avoid Clang < 17 stack protector in startup code
x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
x86/cpu/intel: Limit the non-architectural constant_tsc model checks
x86/mm/pat: Replace Intel x86_model checks with VFM ones
x86/cpu/intel: Fix fast string initialization for extended Families
...
|
||
|
Kan Liang
|
1fbc6c8e52 |
perf/x86: Remove swap_task_ctx()
The pmu specific data is saved in task_struct now. It doesn't need to swap between context. Remove swap_task_ctx() support. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250314172700.438923-6-kan.liang@linux.intel.com |
||
|
Kan Liang
|
d57e94f5b8 |
perf: Supply task information to sched_task()
To save/restore LBR call stack data in system-wide mode, the task_struct information is required. Extend the parameters of sched_task() to supply task_struct information. When schedule in, the LBR call stack data for new task will be restored. When schedule out, the LBR call stack data for old task will be saved. Only need to pass the required task_struct information. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20250314172700.438923-4-kan.liang@linux.intel.com |
||
|
Ingo Molnar
|
1fff9f8730 |
Linux 6.14-rc5
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmfEtgQeHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGUI8H/0TJm0ia8TOseHDT bV0alw4qlNdq7Thi7M5HCsInzyhKImdHDBd/cY3HI2QRZS927WoPHUExDvEd6vUE sETrrBrl/iGJ5nLvXPKkCxXC43ZD3nCI/chBPWwspH2DA/Nih8LAmMkESGVFC7fa TUOKqY1FsAWMYUJ64hP4s9Dwi5XECps7/Di46ypgtr7sVA15jpfF3ePi2mfR73Bm hSfF7E5Xa3E22IBE2NPxvO4fHiYJWbNJk8Vv2ewfHroE/zKsJ/zCMk9mOtFII0P/ TODkBSImFqUx+cDZVc0bJAy8rwA2lNXo3LU28N0Ca4EAoqyyIIdTPQ2wYA82Z2Y2 hE/BeN0= =a9Md -----END PGP SIGNATURE----- Merge tag 'v6.14-rc5' into x86/core, to pick up fixes Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Ingo Molnar
|
ef2f798600 |
Merge branch 'perf/urgent' into perf/core, to pick up dependent patches and fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Kan Liang
|
88ec7eedbb |
perf/x86: Fix low freqency setting issue
Perf doesn't work at low frequencies:
$ perf record -e cpu_core/instructions/ppp -F 120
Error:
The sys_perf_event_open() syscall returned with 22 (Invalid argument)
for event (cpu_core/instructions/ppp).
"dmesg | grep -i perf" may provide additional information.
The limit_period() check avoids a low sampling period on a counter. It
doesn't intend to limit the frequency.
The check in the x86_pmu_hw_config() should be limited to non-freq mode.
The attr.sample_period and attr.sample_freq are union. The
attr.sample_period should not be used to indicate the frequency mode.
Fixes:
|
||
|
Peter Zijlstra
|
72e213a7cc |
x86/ibt: Clean up is_endbr()
Pretty much every caller of is_endbr() actually wants to test something at an address and ends up doing get_kernel_nofault(). Fold the lot into a more convenient helper. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20250207122546.181367417@infradead.org |