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1749 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Tetsuo Handa
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3da6bb4197 |
perf/core: Fix WARN in perf_sigtrap()
Since exit_task_work() runs after perf_event_exit_task_context() updated ctx->task to TASK_TOMBSTONE, perf_sigtrap() from perf_pending_task() might observe event->ctx->task == TASK_TOMBSTONE. Swap the early exit tests in order not to hit WARN_ON_ONCE(). Closes: https://syzkaller.appspot.com/bug?extid=2fe61cb2a86066be6985 Reported-by: syzbot <syzbot+2fe61cb2a86066be6985@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/b1c224bd-97f9-462c-a3e3-125d5e19c983@I-love.SAKURA.ne.jp |
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Peter Zijlstra
|
ba677dbe77 |
perf: Revert to requiring CAP_SYS_ADMIN for uprobes
Jann reports that uprobes can be used destructively when used in the
middle of an instruction. The kernel only verifies there is a valid
instruction at the requested offset, but due to variable instruction
length cannot determine if this is an instruction as seen by the
intended execution stream.
Additionally, Mark Rutland notes that on architectures that mix data
in the text segment (like arm64), a similar things can be done if the
data word is 'mistaken' for an instruction.
As such, require CAP_SYS_ADMIN for uprobes.
Fixes: c9e0924e5c2b ("perf/core: open access to probes for CAP_PERFMON privileged process")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/CAG48ez1n4520sq0XrWYDHKiKxE_+WCfAK+qt9qkY4ZiBGmL-5g@mail.gmail.com
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Luo Gengkun
|
7b4c5a3754 |
perf/core: Fix the WARN_ON_ONCE is out of lock protected region
commit 3172fb986666 ("perf/core: Fix WARN in perf_cgroup_switch()") try to
fix a concurrency problem between perf_cgroup_switch and
perf_cgroup_event_disable. But it does not to move the WARN_ON_ONCE into
lock-protected region, so the warning is still be triggered.
Fixes: 3172fb986666 ("perf/core: Fix WARN in perf_cgroup_switch()")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250626135403.2454105-1-luogengkun@huaweicloud.com
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Leo Yan
|
1476b21832 |
perf/aux: Fix pending disable flow when the AUX ring buffer overruns
If an AUX event overruns, the event core layer intends to disable the
event by setting the 'pending_disable' flag. Unfortunately, the event
is not actually disabled afterwards.
In commit:
ca6c21327c6a ("perf: Fix missing SIGTRAPs")
the 'pending_disable' flag was changed to a boolean. However, the
AUX event code was not updated accordingly. The flag ends up holding a
CPU number. If this number is zero, the flag is taken as false and the
IRQ work is never triggered.
Later, with commit:
2b84def990d3 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")
a new IRQ work 'pending_disable_irq' was introduced to handle event
disabling. The AUX event path was not updated to kick off the work queue.
To fix this bug, when an AUX ring buffer overrun is detected, call
perf_event_disable_inatomic() to initiate the pending disable flow.
Also update the outdated comment for setting the flag, to reflect the
boolean values (0 or 1).
Fixes: 2b84def990d3 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")
Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Liang Kan <kan.liang@linux.intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-perf-users@vger.kernel.org
Link: https://lore.kernel.org/r/20250625170737.2918295-1-leo.yan@arm.com
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Linus Torvalds
|
17ef32ae66 |
- Avoid a crash on a heterogeneous machine where not all cores support the
same hw events features - Avoid a deadlock when throttling events - Document the perf event states more - Make sure a number of perf paths switching off or rescheduling events call perf_cgroup_event_disable() - Make sure perf does task sampling before its userspace mapping is torn down, and not after -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmhXvYYACgkQEsHwGGHe VUotdg//TXchNnZ9xcGKSTFphDQMWVIy1cRWUffWC5ewUhjE9H7+FMZvCmvih8uc uvAsZ92GXE64fuzF0tU/5ybWEgca6HPbgI8aOhnk+vo9Yzxj9/0eO0SKK8qqSvzo ecn/p9yX4/jD86kIo6K279z7ZX8/0tSLselnicrGy1r4RGuaebEAvXDEzZm8p/c6 0MjaTGC4TzkZkGyEeWXRt7jewiWvXO+91TqqwMyrhmIG3cs2TCbPhSn0QowXUZsF PdCJA5Z+vKp6j8n8fohRTFoATSRw5xAoqT+JRmPZ2K3QOCwtf1X0MbM6ZKkapgZO Y4Tp3HPw9yHUu8cyvEEwqU0jDn4J0EaqFgwCrxzvQj9ufkHBlPgNahjXW5upcw4k TV3qEp6KKfywTWWExh6Gjie7y7Hq3aHOkJVCg/ZeQjwMXhpZg7z+mGwh7x08Jn/2 9/bpLG8Gl8eto3G6L1px/NUMc4poZTbSheKrjEMt3Z6ErNoAR4gb7SO547Lvf8HK bty5NZftDUNv42bqqXI0GY7YXKkr1AtHdRDlTeLlc5YmPzhIyG3LgEi4BqN3gyFf emh/CFG/1KT8GWxNCrPW6d01TBRswZjFyBDHL89HO3i0r2nDe98+2fLmllnl2Bv2 EadgGE1XWv6RB5APJ726HXqMgtXM9cHRMogKMhiHNZnwkQba+ug= =nnMl -----END PGP SIGNATURE----- Merge tag 'perf_urgent_for_v6.16_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Avoid a crash on a heterogeneous machine where not all cores support the same hw events features - Avoid a deadlock when throttling events - Document the perf event states more - Make sure a number of perf paths switching off or rescheduling events call perf_cgroup_event_disable() - Make sure perf does task sampling before its userspace mapping is torn down, and not after * tag 'perf_urgent_for_v6.16_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Fix crash in icl_update_topdown_event() perf: Fix the throttle error of some clock events perf: Add comment to enum perf_event_state perf/core: Fix WARN in perf_cgroup_switch() perf: Fix dangling cgroup pointer in cpuctx perf: Fix cgroup state vs ERROR perf: Fix sample vs do_exit() |
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Kan Liang
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bc4394e5e7 |
perf: Fix the throttle error of some clock events
Both ARM and IBM CI reports RCU stall, which can be reproduced by the below perf command. perf record -a -e cpu-clock -- sleep 2 The issue is introduced by the generic throttle patch set, which unconditionally invoke the event_stop() when throttle is triggered. The cpu-clock and task-clock are two special SW events, which rely on the hrtimer. The throttle is invoked in the hrtimer handler. The event_stop()->hrtimer_cancel() waits for the handler to finish, which is a deadlock. Instead of invoking the stop(), the HRTIMER_NORESTART should be used to stop the timer. There may be two ways to fix it: - Introduce a PMU flag to track the case. Avoid the event_stop in perf_event_throttle() if the flag is detected. It has been implemented in the https://lore.kernel.org/lkml/20250528175832.2999139-1-kan.liang@linux.intel.com/ The new flag was thought to be an overkill for the issue. - Add a check in the event_stop. Return immediately if the throttle is invoked in the hrtimer handler. Rely on the existing HRTIMER_NORESTART method to stop the timer. The latter is implemented here. Move event->hw.interrupts = MAX_INTERRUPTS before the stop(). It makes the order the same as perf_event_unthrottle(). Except the patch, no one checks the hw.interrupts in the stop(). There is no impact from the order change. When stops in the throttle, the event should not be updated, stop(event, 0). But the cpu_clock_event_stop() doesn't handle the flag. In logic, it's wrong. But it didn't bring any problems with the old code, because the stop() was not invoked when handling the throttle. Checking the flag before updating the event. Fixes: 9734e25fbf5a ("perf: Fix the throttle logic for a group") Closes: https://lore.kernel.org/lkml/20250527161656.GJ2566836@e132581.arm.com/ Closes: https://lore.kernel.org/lkml/djxlh5fx326gcenwrr52ry3pk4wxmugu4jccdjysza7tlc5fef@ktp4rffawgcw/ Closes: https://lore.kernel.org/lkml/8e8f51d8-af64-4d9e-934b-c0ee9f131293@linux.ibm.com/ Closes: https://lore.kernel.org/lkml/4ce106d0-950c-aadc-0b6a-f0215cd39913@maine.edu/ Reported-by: Leo Yan <leo.yan@arm.com> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com> Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com> Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ian Rogers <irogers@google.com> Link: https://lkml.kernel.org/r/20250606192546.915765-1-kan.liang@linux.intel.com |
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Luo Gengkun
|
3172fb9866 |
perf/core: Fix WARN in perf_cgroup_switch()
There may be concurrency between perf_cgroup_switch and
perf_cgroup_event_disable. Consider the following scenario: after a new
perf cgroup event is created on CPU0, the new event may not trigger
a reprogramming, causing ctx->is_active to be 0. In this case, when CPU1
disables this perf event, it executes __perf_remove_from_context->
list _del_event->perf_cgroup_event_disable on CPU1, which causes a race
with perf_cgroup_switch running on CPU0.
The following describes the details of this concurrency scenario:
CPU0 CPU1
perf_cgroup_switch:
...
# cpuctx->cgrp is not NULL here
if (READ_ONCE(cpuctx->cgrp) == NULL)
return;
perf_remove_from_context:
...
raw_spin_lock_irq(&ctx->lock);
...
# ctx->is_active == 0 because reprogramm is not
# tigger, so CPU1 can do __perf_remove_from_context
# for CPU0
__perf_remove_from_context:
perf_cgroup_event_disable:
...
if (--ctx->nr_cgroups)
...
# this warning will happened because CPU1 changed
# ctx.nr_cgroups to 0.
WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0);
[peterz: use guard instead of goto unlock]
Fixes: db4a835601b7 ("perf/core: Set cgroup in CPU contexts for new cgroup events")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250604033924.3914647-3-luogengkun@huaweicloud.com
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Yeoreum Yun
|
3b7a34aebb |
perf: Fix dangling cgroup pointer in cpuctx
Commit a3c3c6667("perf/core: Fix child_total_time_enabled accounting
bug at task exit") moves the event->state update to before
list_del_event(). This makes the event->state test in list_del_event()
always false; never calling perf_cgroup_event_disable().
As a result, cpuctx->cgrp won't be cleared properly; causing havoc.
Fixes: a3c3c6667("perf/core: Fix child_total_time_enabled accounting bug at task exit")
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: David Wang <00107082@163.com>
Link: https://lore.kernel.org/all/aD2TspKH%2F7yvfYoO@e129823.arm.com/
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Peter Zijlstra
|
61988e36dc |
perf: Fix cgroup state vs ERROR
While chasing down a missing perf_cgroup_event_disable() elsewhere,
Leo Yan found that both perf_put_aux_event() and
perf_remove_sibling_event() were also missing one.
Specifically, the rule is that events that switch to OFF,ERROR need to
call perf_cgroup_event_disable().
Unify the disable paths to ensure this.
Fixes: ab43762ef010 ("perf: Allow normal events to output AUX data")
Fixes: 9f0c4fa111dc ("perf/core: Add a new PERF_EV_CAP_SIBLING event capability")
Reported-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250605123343.GD35970@noisy.programming.kicks-ass.net
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Peter Zijlstra
|
4f6fc78212 |
perf: Fix sample vs do_exit()
Baisheng Gao reported an ARM64 crash, which Mark decoded as being a
synchronous external abort -- most likely due to trying to access
MMIO in bad ways.
The crash further shows perf trying to do a user stack sample while in
exit_mmap()'s tlb_finish_mmu() -- i.e. while tearing down the address
space it is trying to access.
It turns out that we stop perf after we tear down the userspace mm; a
receipie for disaster, since perf likes to access userspace for
various reasons.
Flip this order by moving up where we stop perf in do_exit().
Additionally, harden PERF_SAMPLE_CALLCHAIN and PERF_SAMPLE_STACK_USER
to abort when the current task does not have an mm (exit_mm() makes
sure to set current->mm = NULL; before commencing with the actual
teardown). Such that CPU wide events don't trip on this same problem.
Fixes: c5ebcedb566e ("perf: Add ability to attach user stack dump to sample")
Reported-by: Baisheng Gao <baisheng.gao@unisoc.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250605110815.GQ39944@noisy.programming.kicks-ass.net
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Linus Torvalds
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00c010e130 |
- The 11 patch series "Add folio_mk_pte()" from Matthew Wilcox
simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - The 8 patch series "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - The 3 patch series "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - The 2 patch series "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - The 8 patch series "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - The 6 patch series "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - The 3 patch series "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - The 2 patch series "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - The 3 patch series "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - The 3 patch series "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - The 12 patch series "Always call constructor for kernel page tables" from Kevin Brodsky "ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables". This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - The 9 patch series "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - The 3 patch series "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - The 4 patch series "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - The 6 patch series "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - The 3 patch series "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - The 3 patch series ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - The 7 patch series "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - The 5 patch series "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - The 2 patch series "vmscan: enforce mems_effective during demotion" from Gregory Price "changes reclaim to respect cpuset.mems_effective during demotion when possible". because "presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated." "This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently." - The 2 patch series ""Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - The 3 patch series "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - The 4 patch series "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - The 17 patch series "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - The 7 patch series "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - The 2 patch series "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - The 2 patch series "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - The 4 patch series "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - The 6 patch series "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - The 2 patch series "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - The 8 patch series "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - The 3 patch series "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - The 4 patch series "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - The 6 patch series "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is "yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents." - The 7 patch series "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - The 4 patch series "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaDt5qgAKCRDdBJ7gKXxA ju6XAP9nTiSfRz8Cz1n5LJZpFKEGzLpSihCYyR6P3o1L9oe3mwEAlZ5+XAwk2I5x Qqb/UGMEpilyre1PayQqOnct3aSL9Ao= =tYYm -----END PGP SIGNATURE----- Merge tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ... |
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Kan Liang
|
e800ac5120 |
perf: Only dump the throttle log for the leader
The PERF_RECORD_THROTTLE records are dumped for all throttled events. It's not necessary for group events, which are throttled altogether. Optimize it by only dump the throttle log for the leader. The sample right after the THROTTLE record must be generated by the actual target event. It is good enough for the perf tool to locate the actual target event. Suggested-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20250520181644.2673067-3-kan.liang@linux.intel.com |
||
|
Kan Liang
|
9734e25fbf |
perf: Fix the throttle logic for a group
The current throttle logic doesn't work well with a group, e.g., the
following sampling-read case.
$ perf record -e "{cycles,cycles}:S" ...
$ perf report -D | grep THROTTLE | tail -2
THROTTLE events: 426 ( 9.0%)
UNTHROTTLE events: 425 ( 9.0%)
$ perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 1020120874009167 0x74970 [0x68]: PERF_RECORD_SAMPLE(IP, 0x1):
... sample_read:
.... group nr 2
..... id 0000000000000327, value 000000000cbb993a, lost 0
..... id 0000000000000328, value 00000002211c26df, lost 0
The second cycles event has a much larger value than the first cycles
event in the same group.
The current throttle logic in the generic code only logs the THROTTLE
event. It relies on the specific driver implementation to disable
events. For all ARCHs, the implementation is similar. Only the event is
disabled, rather than the group.
The logic to disable the group should be generic for all ARCHs. Add the
logic in the generic code. The following patch will remove the buggy
driver-specific implementation.
The throttle only happens when an event is overflowed. Stop the entire
group when any event in the group triggers the throttle.
The MAX_INTERRUPTS is set to all throttle events.
The unthrottled could happen in 3 places.
- event/group sched. All events in the group are scheduled one by one.
All of them will be unthrottled eventually. Nothing needs to be
changed.
- The perf_adjust_freq_unthr_events for each tick. Needs to restart the
group altogether.
- The __perf_event_period(). The whole group needs to be restarted
altogether as well.
With the fix,
$ sudo perf report -D | grep PERF_RECORD_SAMPLE -a4 | tail -n 5
0 3573470770332 0x12f5f8 [0x70]: PERF_RECORD_SAMPLE(IP, 0x2):
... sample_read:
.... group nr 2
..... id 0000000000000a28, value 00000004fd3dfd8f, lost 0
..... id 0000000000000a29, value 00000004fd3dfd8f, lost 0
Suggested-by: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-2-kan.liang@linux.intel.com
|
||
|
Kan Liang
|
ca559503b8 |
perf/core: Add the is_event_in_freq_mode() helper to simplify the code
Add a helper to check if an event is in freq mode to improve readability. No functional changes. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250516182853.2610284-2-kan.liang@linux.intel.com |
||
|
Yabin Cui
|
18049c8cff |
perf/aux: Allocate non-contiguous AUX pages by default
perf always allocates contiguous AUX pages based on aux_watermark. However, this contiguous allocation doesn't benefit all PMUs. For instance, ARM SPE and TRBE operate with virtual pages, and Coresight ETR allocates a separate buffer. For these PMUs, allocating contiguous AUX pages unnecessarily exacerbates memory fragmentation. This fragmentation can prevent their use on long-running devices. This patch modifies the perf driver to be memory-friendly by default, by allocating non-contiguous AUX pages. For PMUs requiring contiguous pages (Intel BTS and some Intel PT), the existing PERF_PMU_CAP_AUX_NO_SG capability can be used. For PMUs that don't require but can benefit from contiguous pages (some Intel PT), a new capability, PERF_PMU_CAP_AUX_PREFER_LARGE, is added to maintain their existing behavior. Signed-off-by: Yabin Cui <yabinc@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: James Clark <james.clark@linaro.org> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20250508232642.148767-1-yabinc@google.com |
||
|
David Hildenbrand
|
6e3092d788 |
kernel/events/uprobes: uprobe_write_opcode() rewrite
uprobe_write_opcode() does some pretty low-level things that really, it shouldn't be doing: for example, manually breaking COW by allocating anonymous folios and replacing mapped pages. Further, it does seem to do some shaky things: for example, writing to possible COW-shared anonymous pages or zapping anonymous pages that might be pinned. We're also not taking care of uffd, uffd-wp, softdirty ... although rather corner cases here. Let's just get it right like ordinary ptrace writes would. Let's rewrite the code, leaving COW-breaking to core-MM, triggered by FOLL_FORCE|FOLL_WRITE (note that the code was already using FOLL_FORCE). We'll use GUP to lookup/faultin the page and break COW if required. Then, we'll walk the page tables using a folio_walk to perform our page modification atomically by temporarily unmap the PTE + flushing the TLB. Likely, we could avoid the temporary unmap in case we can just atomically write the instruction, but that will be a separate project. Unfortunately, we still have to implement the zapping logic manually, because we only want to zap in specific circumstances (e.g., page content identical). Note that we can now handle large folios (compound pages) and the shared zeropage just fine, so drop these checks. Link: https://lkml.kernel.org/r/20250321113713.204682-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <olsajiri@gmail.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Namhyung kim <namhyung@kernel.org> Cc: Russel King <linux@armlinux.org.uk> Cc: tongtiangen <tongtiangen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
David Hildenbrand
|
8a5577428e |
kernel/events/uprobes: pass VMA to set_swbp(), set_orig_insn() and uprobe_write_opcode()
We already have the VMA, no need to look it up using get_user_page_vma_remote(). We can now switch to get_user_pages_remote(). Link: https://lkml.kernel.org/r/20250321113713.204682-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <olsajiri@gmail.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Namhyung kim <namhyung@kernel.org> Cc: Russel King <linux@armlinux.org.uk> Cc: tongtiangen <tongtiangen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
David Hildenbrand
|
b56e644665 |
kernel/events/uprobes: pass VMA instead of MM to remove_breakpoint()
Patch series "kernel/events/uprobes: uprobe_write_opcode() rewrite", v3. Currently, uprobe_write_opcode() implements COW-breaking manually, which is really far from ideal. Further, there is interest in supporting uprobes on hugetlb pages [1], and leaving at least the COW-breaking to the core will make this much easier. Also, I think the current code doesn't really handle some things properly (see patch #3) when replacing/zapping pages. Let's rewrite it, to leave COW-breaking to the fault handler, and handle registration/unregistration by temporarily unmapping the anonymous page, modifying it, and mapping it again. We still have to implement zapping of anonymous pages ourselves, unfortunately. We could look into not performing the temporary unmapping if we can perform the write atomically, which would likely also make adding hugetlb support a lot easier. But, limited (e.g., only PMD/PUD) hugetlb support could be added on top of this with some tweaking. Note that we now won't have to allocate another anonymous folio when unregistering (which will be beneficial for hugetlb as well), we can simply modify the already-mapped one from the registration (if any). When registering a uprobe, we'll first trigger a ptrace-like write fault to break COW, to then modify the already-mapped page. Briefly sanity tested with perf probes and with the bpf uprobes selftest. This patch (of 3): Pass VMA instead of MM to remove_breakpoint() and remove the "MM" argument from install_breakpoint(), because it can easily be derived from the VMA. Link: https://lkml.kernel.org/r/20250321113713.204682-1-david@redhat.com Link: https://lkml.kernel.org/r/20250321113713.204682-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jiri Olsa <olsajiri@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Namhyung kim <namhyung@kernel.org> Cc: Russel King <linux@armlinux.org.uk> Cc: tongtiangen <tongtiangen@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Frederic Weisbecker
|
881097c054 |
perf: Fix confusing aux iteration
While an event tears down all links to it as an aux, the iteration happens on the event's group leader instead of the group itself. If the event is a group leader, it has no effect because the event is also its own group leader. But otherwise there would be a risk to detach all the siblings events from the wrong group leader. It just happens to work because each sibling's aux link is tested against the right event before proceeding. Also the ctx lock is the same for the events and their group leader so the iteration is safe. Yet the iteration is confusing. Clarify the actual intent. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20250424161128.29176-5-frederic@kernel.org |
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|
Frederic Weisbecker
|
d20eb2d5fe |
perf: Fix irq work dereferencing garbage
The following commit:
da916e96e2de ("perf: Make perf_pmu_unregister() useable")
has introduced two significant event's parent lifecycle changes:
1) An event that has exited now has EVENT_TOMBSTONE as a parent.
This can result in a situation where the delayed wakeup irq_work can
accidentally dereference EVENT_TOMBSTONE on:
CPU 0 CPU 1
----- -----
__schedule()
local_irq_disable()
rq_lock()
<NMI>
perf_event_overflow()
irq_work_queue(&child->pending_irq)
</NMI>
perf_event_task_sched_out()
raw_spin_lock(&ctx->lock)
ctx_sched_out()
ctx->is_active = 0
event_sched_out(child)
raw_spin_unlock(&ctx->lock)
perf_event_release_kernel(parent)
perf_remove_from_context(child)
raw_spin_lock_irq(&ctx->lock)
// Sees !ctx->is_active
// Removes from context inline
__perf_remove_from_context(child)
perf_child_detach(child)
event->parent = EVENT_TOMBSTONE
raw_spin_rq_unlock_irq(rq);
<IRQ>
perf_pending_irq()
perf_event_wakeup(child)
ring_buffer_wakeup(child)
rcu_dereference(child->parent->rb) <--- CRASH
This also concerns the call to kill_fasync() on parent->fasync.
2) The final parent reference count decrement can now happen before the
the final child reference count decrement. ie: the parent can now
be freed before its child. On PREEMPT_RT, this can result in a
situation where the delayed wakeup irq_work can accidentally
dereference a freed parent:
CPU 0 CPU 1 CPU 2
----- ----- ------
perf_pmu_unregister()
pmu_detach_events()
pmu_get_event()
atomic_long_inc_not_zero(&child->refcount)
<NMI>
perf_event_overflow()
irq_work_queue(&child->pending_irq);
</NMI>
<IRQ>
irq_work_run()
wake_irq_workd()
</IRQ>
preempt_schedule_irq()
=========> SWITCH to workd
irq_work_run_list()
perf_pending_irq()
perf_event_wakeup(child)
ring_buffer_wakeup(child)
event = child->parent
perf_event_release_kernel(parent)
// Not last ref, PMU holds it
put_event(child)
// Last ref
put_event(parent)
free_event()
call_rcu(...)
rcu_core()
free_event_rcu()
rcu_dereference(event->rb) <--- CRASH
This also concerns the call to kill_fasync() on parent->fasync.
The "easy" solution to 1) is to check that event->parent is not
EVENT_TOMBSTONE on perf_event_wakeup() (including both ring buffer
and fasync uses).
The "easy" solution to 2) is to turn perf_event_wakeup() to wholefully
run under rcu_read_lock().
However because of 2), sanity would prescribe to make event::parent
an __rcu pointer and annotate each and every users to prove they are
reliable.
Propose an alternate solution and restore the stable pointer to the
parent until all its children have called _free_event() themselves to
avoid any further accident. Also revert the EVENT_TOMBSTONE design
that is mostly here to determine which caller of perf_event_exit_event()
must perform the refcount decrement on a child event matching the
increment in inherit_event().
Arrange instead for checking the attach state of an event prior to its
removal and decrement the refcount of the child accordingly.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
||
|
Frederic Weisbecker
|
22d38babb3 |
perf: Fix failing inherit_event() doing extra refcount decrement on parent
When inherit_event() fails after the child allocation but before the
parent refcount has been incremented, calling put_event() wrongly
decrements the reference to the parent, risking to free it too early.
Also pmu_get_event() can't be holding a reference to the child
concurrently at this point since it is under pmus_srcu critical section.
Fix it with restoring the deleted free_event() function and call it on
the failing child in order to free it directly under the verified
assumption that its refcount is only 1. The refcount to the parent is
then voluntarily omitted.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250424161128.29176-2-frederic@kernel.org
|
||
|
Qing Wang
|
f51972e6f8 |
perf/core: Fix broken throttling when max_samples_per_tick=1
According to the throttling mechanism, the pmu interrupts number can not
exceed the max_samples_per_tick in one tick. But this mechanism is
ineffective when max_samples_per_tick=1, because the throttling check is
skipped during the first interrupt and only performed when the second
interrupt arrives.
Perhaps this bug may cause little influence in one tick, but if in a
larger time scale, the problem can not be underestimated.
When max_samples_per_tick = 1:
Allowed-interrupts-per-second max-samples-per-second default-HZ ARCH
200 100 100 X86
500 250 250 ARM64
...
Obviously, the pmu interrupt number far exceed the user's expect.
Fixes: e050e3f0a71b ("perf: Fix broken interrupt rate throttling")
Signed-off-by: Qing Wang <wangqing7171@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250405141635.243786-3-wangqing7171@gmail.com
|
||
|
Peter Zijlstra
|
1caafd919e |
Merge branch 'perf/urgent'
Merge urgent fixes for dependencies. Signed-off-by: Peter Zijlstra <peterz@infradead.org> |
||
|
Namhyung Kim
|
0db61388b3 |
perf/core: Change to POLLERR for pinned events with error
Commit:
f4b07fd62d4d11d5 ("perf/core: Use POLLHUP for pinned events in error")
started to emit POLLHUP for pinned events in an error state.
But the POLLHUP is also used to signal events that the attached task is
terminated. To distinguish pinned per-task events in the error state
it would need to check if the task is live.
Change it to POLLERR to make it clear.
Suggested-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250422223318.180343-1-namhyung@kernel.org
|
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Peter Zijlstra
|
b02b41c827 |
perf/core: Fix event timekeeping merge
Due to an oversight in merging:
da916e96e2de ("perf: Make perf_pmu_unregister() useable")
on top of:
a3c3c66670ce ("perf/core: Fix child_total_time_enabled accounting bug at task exit")
the timekeeping fix from this latter patch got undone.
Redo it.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20250417080815.GI38216@noisy.programming.kicks-ass.net
|
||
|
Peter Zijlstra
|
162c9e3faf |
perf/core: Fix event->parent life-time issue
Due to an oversight in merging:
da916e96e2de ("perf: Make perf_pmu_unregister() useable")
on top of:
56799bc03565 ("perf: Fix hang while freeing sigtrap event")
.. it is now possible to hit put_event(EVENT_TOMBSTONE), which makes
the computer sad.
This also means that for the event->parent == EVENT_TOMBSTONE, the
put_event() matching inherit_event() has gone missing.
Previously this was done in perf_event_release_kernel() after calling
perf_remove_from_context(), but with it delegated to put_event(), this
case is now entirely missed, leading to leaks.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Reported-by: kernel test robot <oliver.sang@intel.com>
Tested-by: kernel test robot <oliver.sang@intel.com>
Tested-by: James Clark <james.clark@linaro.org>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/oe-lkp/202504131701.941039cd-lkp@intel.com
Link: https://lkml.kernel.org/r/20250415131446.GN5600@noisy.programming.kicks-ass.net
|
||
|
Frederic Weisbecker
|
2839f393c6 |
perf/core: Fix put_ctx() ordering
So there are three situations:
* If perf_event_free_task() has removed all the children from the parent list
before perf_event_release_kernel() got a chance to even iterate them, then
it's all good as there is no get_ctx() pending.
* If perf_event_release_kernel() iterates a child event, but it gets freed
meanwhile by perf_event_free_task() while the mutexes are temporarily
unlocked, it's all good because while locking again the ctx mutex,
perf_event_release_kernel() observes TASK_TOMBSTONE.
* But if perf_event_release_kernel() frees the child event before
perf_event_free_task() got a chance, we may face this scenario:
perf_event_release_kernel() perf_event_free_task()
-------------------------- ------------------------
mutex_lock(&event->child_mutex)
get_ctx(child->ctx)
mutex_unlock(&event->child_mutex)
mutex_lock(ctx->mutex)
mutex_lock(&event->child_mutex)
perf_remove_from_context(child)
mutex_unlock(&event->child_mutex)
mutex_unlock(ctx->mutex)
// This lock acquires ctx->refcount == 2
// visibility
mutex_lock(ctx->mutex)
ctx->task = TASK_TOMBSTONE
mutex_unlock(ctx->mutex)
wait_var_event()
// enters prepare_to_wait() since
// ctx->refcount == 2
// is guaranteed to be seen
set_current_state(TASK_INTERRUPTIBLE)
smp_mb()
if (ctx->refcount != 1)
schedule()
put_ctx()
// NOT fully ordered! Only RELEASE semantics
refcount_dec_and_test()
atomic_fetch_sub_release()
// So TASK_TOMBSTONE is not guaranteed to be seen
if (ctx->task == TASK_TOMBSTONE)
wake_up_var()
Basically it's a broken store buffer:
perf_event_release_kernel() perf_event_free_task()
-------------------------- ------------------------
ctx->task = TASK_TOMBSTONE smp_store_release(&ctx->refcount, ctx->refcount - 1)
smp_mb()
READ_ONCE(ctx->refcount) READ_ONCE(ctx->task)
So we need a smp_mb__after_atomic() before looking at ctx->task.
Fixes: 59f3aa4a3ee2 ("perf: Simplify perf_event_free_task() wait")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/Z_ZvmEhjkAhplCBE@localhost.localdomain
|
||
|
Peter Zijlstra
|
f6938a562a |
perf/core: Fix perf-stat / read()
In the zeal to adjust all event->state checks to include the new
REVOKED state, one adjustment was made in error. Notably it resulted
in read() on the perf filedesc to stop working for any state lower
than ERROR, specifically EXIT.
This leads to problems with (among others) perf-stat, which wants to
read the counts after a program has finished execution.
Fixes: da916e96e2de ("perf: Make perf_pmu_unregister() useable")
Reported-by: "Mi, Dapeng" <dapeng1.mi@linux.intel.com>
Reported-by: James Clark <james.clark@linaro.org>
Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/77036114-8723-4af9-a068-1d535f4e2e81@linaro.org
Link: https://lore.kernel.org/r/20250417080725.GH38216@noisy.programming.kicks-ass.net
|
||
|
Peter Zijlstra
|
da916e96e2 |
perf: Make perf_pmu_unregister() useable
Previously it was only safe to call perf_pmu_unregister() if there were no active events of that pmu around -- which was impossible to guarantee since it races all sorts against perf_init_event(). Rework the whole thing by: - keeping track of all events for a given pmu - 'hiding' the pmu from perf_init_event() - waiting for the appropriate (s)rcu grace periods such that all prior references to the PMU will be completed - detaching all still existing events of that pmu (see first point) and moving them to a new REVOKED state. - actually freeing the pmu data. Where notably the new REVOKED state must inhibit all event actions from reaching code that wants to use event->pmu. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193723.525402029@infradead.org |
||
|
Peter Zijlstra
|
4da0600eda |
perf: Rename perf_event_exit_task(.child)
The task passed to perf_event_exit_task() is not a child, it is current. Fix this confusing naming, since much of the rest of the code also relies on it being current. Specifically, both exec() and exit() callers use it with current as the argument. Notably, task_ctx_sched_out() doesn't make much sense outside of current. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193305.486326750@infradead.org |
||
|
Peter Zijlstra
|
9066136502 |
perf: Unify perf_event_free_task() / perf_event_exit_task_context()
Both perf_event_free_task() and perf_event_exit_task_context() are very similar, except perf_event_exit_task_context() is a little more generic / makes less assumptions. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193723.274039710@infradead.org |
||
|
Peter Zijlstra
|
3e8671e00e |
perf: Simplify perf_event_release_kernel()
There is no good reason to have the free list anymore. It is possible to call free_event() after the locks have been dropped in the main loop. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193723.151721102@infradead.org |
||
|
Peter Zijlstra
|
59f3aa4a3e |
perf: Simplify perf_event_free_task() wait
Simplify the code by moving the duplicated wakeup condition into put_ctx(). Notably, wait_var_event() is in perf_event_free_task() and will have set ctx->task = TASK_TOMBSTONE. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193723.044499344@infradead.org |
||
|
Peter Zijlstra
|
0a00a43b8c |
perf: Simplify child event tear-down
Currently perf_event_release_kernel() will iterate the child events and attempt tear-down. However, it removes them from the child_list using list_move(), notably skipping the state management done by perf_child_detach(). Crucially, it fails to clear PERF_ATTACH_CHILD, which opens the door for a concurrent perf_remove_from_context() to race. This way child_list management stays fully serialized using child_mutex. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193305.486326750@infradead.org |
||
|
Peter Zijlstra
|
7ed9138a72 |
perf: Ensure bpf_perf_link path is properly serialized
Ravi reported that the bpf_perf_link_attach() usage of perf_event_set_bpf_prog() is not serialized by ctx->mutex, unlike the PERF_EVENT_IOC_SET_BPF case. Reported-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lkml.kernel.org/r/20250307193305.486326750@infradead.org |
||
|
Frederic Weisbecker
|
56799bc035 |
perf: Fix hang while freeing sigtrap event
Perf can hang while freeing a sigtrap event if a related deferred
signal hadn't managed to be sent before the file got closed:
perf_event_overflow()
task_work_add(perf_pending_task)
fput()
task_work_add(____fput())
task_work_run()
____fput()
perf_release()
perf_event_release_kernel()
_free_event()
perf_pending_task_sync()
task_work_cancel() -> FAILED
rcuwait_wait_event()
Once task_work_run() is running, the list of pending callbacks is
removed from the task_struct and from this point on task_work_cancel()
can't remove any pending and not yet started work items, hence the
task_work_cancel() failure and the hang on rcuwait_wait_event().
Task work could be changed to remove one work at a time, so a work
running on the current task can always cancel a pending one, however
the wait / wake design is still subject to inverted dependencies when
remote targets are involved, as pictured by Oleg:
T1 T2
fd = perf_event_open(pid => T2->pid); fd = perf_event_open(pid => T1->pid);
close(fd) close(fd)
<IRQ> <IRQ>
perf_event_overflow() perf_event_overflow()
task_work_add(perf_pending_task) task_work_add(perf_pending_task)
</IRQ> </IRQ>
fput() fput()
task_work_add(____fput()) task_work_add(____fput())
task_work_run() task_work_run()
____fput() ____fput()
perf_release() perf_release()
perf_event_release_kernel() perf_event_release_kernel()
_free_event() _free_event()
perf_pending_task_sync() perf_pending_task_sync()
rcuwait_wait_event() rcuwait_wait_event()
Therefore the only option left is to acquire the event reference count
upon queueing the perf task work and release it from the task work, just
like it was done before 3a5465418f5f ("perf: Fix event leak upon exec and file release")
but without the leaks it fixed.
Some adjustments are necessary to make it work:
* A child event might dereference its parent upon freeing. Care must be
taken to release the parent last.
* Some places assuming the event doesn't have any reference held and
therefore can be freed right away must instead put the reference and
let the reference counting to its job.
Reported-by: "Yi Lai" <yi1.lai@linux.intel.com>
Closes: https://lore.kernel.org/all/Zx9Losv4YcJowaP%2F@ly-workstation/
Reported-by: syzbot+3c4321e10eea460eb606@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/673adf75.050a0220.87769.0024.GAE@google.com/
Fixes: 3a5465418f5f ("perf: Fix event leak upon exec and file release")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250304135446.18905-1-frederic@kernel.org
|
||
|
Andrii Nakryiko
|
0cd575cab1 |
uprobes: Avoid false-positive lockdep splat on CONFIG_PREEMPT_RT=y in the ri_timer() uprobe timer callback, use raw_write_seqcount_*()
Avoid a false-positive lockdep warning in the CONFIG_PREEMPT_RT=y
configuration when using write_seqcount_begin() in the uprobe timer
callback by using raw_write_* APIs.
Uprobe's use of timer callback is guaranteed to not race with itself
for a given uprobe_task, and as such seqcount's insistence on having
preemption disabled on the writer side is irrelevant. So switch to
raw_ variants of seqcount API instead of disabling preemption unnecessarily.
Also, point out in the comments more explicitly why we use seqcount
despite our reader side being rather simple and never retrying. We favor
well-maintained kernel primitive in favor of open-coding our own memory
barriers.
Fixes: 8622e45b5da1 ("uprobes: Reuse return_instances between multiple uretprobes within task")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20250404194848.2109539-1-andrii@kernel.org
|
||
|
Gabriel Shahrouzi
|
0ba3a4ab76 |
perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init
Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines, resolving the WARN_ON_ONCE(). To resolve it, defer the refcount update and child_event->ctx assignment directly after child_event->pmu_ctx is set but before checking if the parent event is orphaned. The cleanup routine depends on event->pmu_ctx being non-NULL before it verifies event->ctx is non-NULL. This also maintains the author's original intent of passing in child_ctx to find_get_pmu_context before its refcount/assignment. [ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ] Reported-by: syzbot+ff3aa851d46ab82953a3@syzkaller.appspotmail.com Signed-off-by: Gabriel Shahrouzi <gshahrouzi@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: https://lore.kernel.org/r/20250405203036.582721-1-gshahrouzi@gmail.com Closes: https://syzkaller.appspot.com/bug?extid=ff3aa851d46ab82953a3 |
||
|
Linus Torvalds
|
dda8887894 |
Fix a perf events time accounting bug.
Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmfyslURHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1jGRw/8CZ3NyJI/g0StlH/csA4a1f58JBpIR1XY I+uUXuTEsd1yS1TMLz5WeK8hsLp1ZCnehojLcjY4Ee/8Tp+mBRlgYuvgJ/T7wBbI OOJjsSku2IHk+D3RshUJt3kG9deeBIkZSQON+HeJ28WaYzXs0qpNKnS3a5RMLJWo k+PS4IpRaWN5a/YIxC2XMGGxEBE0W9wJXXthIbbSozuu1uXuNiZ92cxAa8IzPiZn 4oThM4dq1XyR4NvcjWf23206fUUVEzBoK/XS15oRK3Nk2oHMZ2ilruTxkBEaFf50 6Nr2zNVVQ6/l6wR9DYMAQTE+UHFMJGb7+l1oSARLFKPKc9h7nj4+eItBMzkzbxXS wAZX0nq+kkXAr2DABHBxeT6q10OGjLHCOTrE4AfU0Iss8kmNhRPiqwuXT87dOcDa OWH75mrP6rkGdUdExV5+ZdB1GhBiomg/KB3YCILeM2OjrluXtZC1aHYiuS1RPh24 KaH6H20WtRzNbF7uxRPBwOS1U3xHfFd+usZ1XnBzl2DWNz09hyJUjuG8B90EmjvI POQ2lyepVg2tIV/uplM0sb9J39tNZNXRlfQrmjsyuHk+1kmK+bh0lL9WVe7qQqVB jEX6X0yqTdLAMyRllcwRwtIhgb1u89PFRhnC3IKRfuJeuj07LTgnkOYSVwp7YQ+C p7eIplRJhrw= =slQk -----END PGP SIGNATURE----- Merge tag 'perf-urgent-2025-04-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf event fix from Ingo Molnar: "Fix a perf events time accounting bug" * tag 'perf-urgent-2025-04-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix child_total_time_enabled accounting bug at task exit |
||
|
Jeff Xu
|
3d38922abf |
mseal sysmap: uprobe mapping
Provide support to mseal the uprobe mapping. Unlike other system mappings, the uprobe mapping is not established during program startup. However, its lifetime is the same as the process's lifetime. It could be sealed from creation. Test was done with perf tool, and observe the uprobe mapping is sealed. Link: https://lkml.kernel.org/r/20250305021711.3867874-6-jeffxu@google.com Signed-off-by: Jeff Xu <jeffxu@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Kees Cook <kees@kernel.org> Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org> Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Anna-Maria Behnsen <anna-maria@linutronix.de> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Benjamin Berg <benjamin@sipsolutions.net> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: David S. Miller <davem@davemloft.net> Cc: Elliot Hughes <enh@google.com> Cc: Florian Faineli <f.fainelli@gmail.com> Cc: Greg Ungerer <gerg@kernel.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Jason A. Donenfeld <jason@zx2c4.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: Linus Waleij <linus.walleij@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Mike Rapoport <mike.rapoport@gmail.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Stephen Röttger <sroettger@google.com> Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Linus Torvalds
|
eb0ece1602 |
- The 6 patch series "Enable strict percpu address space checks" from
Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was founf to be incorrect. - The 4 patch series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The 17 patch series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The 5 patch series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The 4 patch series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The 12 patch series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The 2 patch series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The 3 patch series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The 4 patch series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The 4 patch series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The 4 patch series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The 18 patch series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The 27 patch series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The 12 patch series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The 8 patch series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The 2 patch series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The 3 patch series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The 3 patch series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The 3 patch series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The 9 patch series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The 5 patch series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The 13 patch series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The 13 patch series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The 3 patch series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The 8 patch series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The 2 patch series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The 3 patch series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The 4 patch series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The 3 patch series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The 5 patch series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The 5 patch series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The 4 patch series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The 2 patch series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. -----BEGIN PGP SIGNATURE----- iHQEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nZaAAKCRDdBJ7gKXxA jsOWAPiP4r7CJHMZRK4eyJOkvS1a1r+TsIarrFZtjwvf/GIfAQCEG+JDxVfUaUSF Ee93qSSLR1BkNdDw+931Pu0mXfbnBw== =Pn2K -----END PGP SIGNATURE----- Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ... |
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Yeoreum Yun
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a3c3c66670 |
perf/core: Fix child_total_time_enabled accounting bug at task exit
The perf events code fails to account for total_time_enabled of
inactive events.
Here is a failure case for accounting total_time_enabled for
CPU PMU events:
sudo ./perf stat -vvv -e armv8_pmuv3_0/event=0x08/ -e armv8_pmuv3_1/event=0x08/ -- stress-ng --pthread=2 -t 2s
...
armv8_pmuv3_0/event=0x08/: 1138698008 2289429840 2174835740
armv8_pmuv3_1/event=0x08/: 1826791390 1950025700 847648440
` ` `
` ` > total_time_running with child
` > total_time_enabled with child
> count with child
Performance counter stats for 'stress-ng --pthread=2 -t 2s':
1,138,698,008 armv8_pmuv3_0/event=0x08/ (94.99%)
1,826,791,390 armv8_pmuv3_1/event=0x08/ (43.47%)
The two events above are opened on two different CPU PMUs, for example,
each event is opened for a cluster in an Arm big.LITTLE system, they
will never run on the same CPU. In theory, the total enabled time should
be same for both events, as two events are opened and closed together.
As the result show, the two events' total enabled time including
child event is different (2289429840 vs 1950025700).
This is because child events are not accounted properly
if a event is INACTIVE state when the task exits:
perf_event_exit_event()
`> perf_remove_from_context()
`> __perf_remove_from_context()
`> perf_child_detach() -> Accumulate child_total_time_enabled
`> list_del_event() -> Update child event's time
The problem is the time accumulation happens prior to child event's
time updating. Thus, it misses to account the last period's time when
the event exits.
The perf core layer follows the rule that timekeeping is tied to state
change. To address the issue, make __perf_remove_from_context()
handle the task exit case by passing 'DETACH_EXIT' to it and
invoke perf_event_state() for state alongside with accounting the time.
Then, perf_child_detach() populates the time into the parent's time metrics.
After this patch, the bug is fixed:
sudo ./perf stat -vvv -e armv8_pmuv3_0/event=0x08/ -e armv8_pmuv3_1/event=0x08/ -- stress-ng --pthread=2 -t 10s
...
armv8_pmuv3_0/event=0x08/: 15396770398 32157963940 21898169000
armv8_pmuv3_1/event=0x08/: 22428964974 32157963940 10259794940
Performance counter stats for 'stress-ng --pthread=2 -t 10s':
15,396,770,398 armv8_pmuv3_0/event=0x08/ (68.10%)
22,428,964,974 armv8_pmuv3_1/event=0x08/ (31.90%)
[ mingo: Clarified the changelog. ]
Fixes: ef54c1a476aef ("perf: Rework perf_event_exit_event()")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Leo Yan <leo.yan@arm.com>
Link: https://lore.kernel.org/r/20250326082003.1630986-1-yeoreum.yun@arm.com
|
||
|
Linus Torvalds
|
054570267d |
lsm/stable-6.15 PR 20250323
-----BEGIN PGP SIGNATURE----- iQJIBAABCAAyFiEES0KozwfymdVUl37v6iDy2pc3iXMFAmfgWgMUHHBhdWxAcGF1 bC1tb29yZS5jb20ACgkQ6iDy2pc3iXNW5RAAvCDq5gBtY0aTNlULe637EVLSh+t8 PkSzHzu/NlzU6BfjtwSm2fuML8welTGxSwUPxUzMCI91gPdkGeFktefavT3xa+QI BHWROn7fEJ/KmRZvngPeIkgLr5xhF5nBJmc/Jw71qem20zRzNgJnpzMX16d10Phx dxd2xOO1qM3bv6Z9RcIssZRGaN+PHngpWWg+0B69XuaBUso87S6NDyKNn1XPmvoz as96k+Wk/xAZGVEeCbs/+H5rBx6DLg+FfTRa06Oh4BFsqedpkDPxLrTgCJGJkA0H dsK6O/993zvjx0Jn4ZPoJ9n35S82BmkCsz4bGq1xVl6FYUiMcm3/8yO41wllS+w4 j+RlTU/RIdB7n8EKyMMl1hj1stTvt3Bi9F5Cbf7ZEv0snfR00K4KVpi17jnFjUHv kpOiEtXZb/NGQip7UAuUq0PisfqbiO4jJurYHRetDgv1WCy6+C8ufM5t6I+cnvmG VG+dlxcW+rDIn6bLRVuGi9TJRsQ6eox9ipa+qEKNNiOXgftELcgT7m74nAS5m0uv n5rDa221nPXecEB0X7d6YUFk711lly90dbelNeLrmv1w6jl8L1PpS1oBaW+UzGu9 46eGBd6pzu9otvK9WVyDEdotDOCrgH0sd7pTetqDhLJZ7KrGwyyqO2gD/JroUKcC lnxBQwPnat86iI8= =oxfV -----END PGP SIGNATURE----- Merge tag 'lsm-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull lsm updates from Paul Moore: - Various minor updates to the LSM Rust bindings Changes include marking trivial Rust bindings as inlines and comment tweaks to better reflect the LSM hooks. - Add LSM/SELinux access controls to io_uring_allowed() Similar to the io_uring_disabled sysctl, add a LSM hook to io_uring_allowed() to enable LSMs a simple way to enforce security policy on the use of io_uring. This pull request includes SELinux support for this new control using the io_uring/allowed permission. - Remove an unused parameter from the security_perf_event_open() hook The perf_event_attr struct parameter was not used by any currently supported LSMs, remove it from the hook. - Add an explicit MAINTAINERS entry for the credentials code We've seen problems in the past where patches to the credentials code sent by non-maintainers would often languish on the lists for multiple months as there was no one explicitly tasked with the responsibility of reviewing and/or merging credentials related code. Considering that most of the code under security/ has a vested interest in ensuring that the credentials code is well maintained, I'm volunteering to look after the credentials code and Serge Hallyn has also volunteered to step up as an official reviewer. I posted the MAINTAINERS update as a RFC to LKML in hopes that someone else would jump up with an "I'll do it!", but beyond Serge it was all crickets. - Update Stephen Smalley's old email address to prevent confusion This includes a corresponding update to the mailmap file. * tag 'lsm-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: mailmap: map Stephen Smalley's old email addresses lsm: remove old email address for Stephen Smalley MAINTAINERS: add Serge Hallyn as a credentials reviewer MAINTAINERS: add an explicit credentials entry cred,rust: mark Credential methods inline lsm,rust: reword "destroy" -> "release" in SecurityCtx lsm,rust: mark SecurityCtx methods inline perf: Remove unnecessary parameter of security check lsm: fix a missing security_uring_allowed() prototype io_uring,lsm,selinux: add LSM hooks for io_uring_setup() io_uring: refactor io_uring_allowed() |
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|
Linus Torvalds
|
a50b4fe095 |
A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to the callback pointer. This turned out to be suboptimal for the upcoming Rust integration and is obviously a silly implementation to begin with. This cleanup replaces the hrtimer_init(T); T->function = cb; sequence with hrtimer_setup(T, cb); The conversion was done with Coccinelle and a few manual fixups. Once the conversion has completely landed in mainline, hrtimer_init() will be removed and the hrtimer::function becomes a private member. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmff5jQTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoVvRD/wKtuwmiA66NJFgXC0qVq82A6fO3bY8 GBdbfysDJIbqGu5PTcULTbJ8qkqv3jeLUv6CcXvS4sZ7y/uJQl2lzf8yrD/0bbwc rLI6sHiPSZmK93kNVN4X5H7kvt7cE/DYC9nnEOgK3BY5FgKc4n9887d4aVBhL8Lv ODwVXvZ+xi351YCj7qRyPU24zt/p4tkkT1o2k4a0HBluqLI0D+V20fke9IERUL8r d1uWKlcn0TqYDesE8HXKIhbst3gx52rMJrXBJDHwFmG6v8Pj1fkTXCVpPo8QcBz8 OTVkpomN9f/Tx4+GZwhZOF86LhLL3OhxD6pT7JhFCXdmSGv+Ez8uyk1YZysM/XpV Juy/1yAcBpDIDkmhMFGdAAn48Nn9Fotty0r4je60zSEp1d/4QMXcFme29qr2JTUE iWnQ/HD6DxUjVHqy7CYvvo26Xegg1C7qgyOVt4PYZwAM1VKF5P3kzYTb4SAdxtop Tpji1sfW9QV08jqMNo6XntD32DSP9S2HqjO9LwBw700jnx2jjJ35fcJs6iodMOUn gckIZLMn3L0OoglPdyA5O7SNTbKE7aFiRKdnT/cJtR3Fa39Qu27CwC5gfiyuie9I Q+LG8GLuYSBHXAR+PBK4GWlzJ7Dn8k3eqmbnLeKpRMsU6ZzcttgA64xhaviN2wN0 iJbvLJeisXr3GA== =bYAX -----END PGP SIGNATURE----- Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer cleanups from Thomas Gleixner: "A treewide hrtimer timer cleanup hrtimers are initialized with hrtimer_init() and a subsequent store to the callback pointer. This turned out to be suboptimal for the upcoming Rust integration and is obviously a silly implementation to begin with. This cleanup replaces the hrtimer_init(T); T->function = cb; sequence with hrtimer_setup(T, cb); The conversion was done with Coccinelle and a few manual fixups. Once the conversion has completely landed in mainline, hrtimer_init() will be removed and the hrtimer::function becomes a private member" * tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits) wifi: rt2x00: Switch to use hrtimer_update_function() io_uring: Use helper function hrtimer_update_function() serial: xilinx_uartps: Use helper function hrtimer_update_function() ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup() RDMA: Switch to use hrtimer_setup() virtio: mem: Switch to use hrtimer_setup() drm/vmwgfx: Switch to use hrtimer_setup() drm/xe/oa: Switch to use hrtimer_setup() drm/vkms: Switch to use hrtimer_setup() drm/msm: Switch to use hrtimer_setup() drm/i915/request: Switch to use hrtimer_setup() drm/i915/uncore: Switch to use hrtimer_setup() drm/i915/pmu: Switch to use hrtimer_setup() drm/i915/perf: Switch to use hrtimer_setup() drm/i915/gvt: Switch to use hrtimer_setup() drm/i915/huc: Switch to use hrtimer_setup() drm/amdgpu: Switch to use hrtimer_setup() stm class: heartbeat: Switch to use hrtimer_setup() i2c: Switch to use hrtimer_setup() iio: Switch to use hrtimer_setup() ... |
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Kan Liang
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bd2da08d93 |
perf: Clean up pmu specific data
The pmu specific data is saved in task_struct now. Remove it from event context structure. Remove swap_task_ctx() as well. 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/20250314172700.438923-7-kan.liang@linux.intel.com |
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Kan Liang
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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 |
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Kan Liang
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506e64e710 |
perf: attach/detach PMU specific data
The LBR call stack data has to be saved/restored during context switch to fix the shorter LBRs call stacks issue in the system-wide mode. Allocate PMU specific data and attach them to the corresponding task_struct during LBR call stack monitoring. When a LBR call stack event is accounted, the perf_ctx_data for the related tasks will be allocated/attached by attach_perf_ctx_data(). When a LBR call stack event is unaccounted, the perf_ctx_data for related tasks will be detached/freed by detach_perf_ctx_data(). The LBR call stack event could be a per-task event or a system-wide event. - For a per-task event, perf only allocates the perf_ctx_data for the current task. If the allocation fails, perf will error out. - For a system-wide event, perf has to allocate the perf_ctx_data for both the existing tasks and the upcoming tasks. The allocation for the existing tasks is done in perf_event_alloc(). If any allocation fails, perf will error out. The allocation for the new tasks will be done in perf_event_fork(). A global reader/writer semaphore, global_ctx_data_rwsem, is added to address the global race. - The perf_ctx_data only be freed by the last LBR call stack event. The number of the per-task events is tracked by refcount of each task. Since the system-wide events impact all tasks, it's not practical to go through the whole task list to update the refcount for each system-wide event. The number of system-wide events is tracked by a global variable global_ctx_data_ref. Suggested-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> 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/20250314172700.438923-3-kan.liang@linux.intel.com |
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Kan Liang
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cb43691293 |
perf: Save PMU specific data in task_struct
Some PMU specific data has to be saved/restored during context switch,
e.g. LBR call stack data. Currently, the data is saved in event context
structure, but only for per-process event. For system-wide event,
because of missing the LBR call stack data after context switch, LBR
callstacks are always shorter in comparison to per-process mode.
For example,
Per-process mode:
$perf record --call-graph lbr -- taskset -c 0 ./tchain_edit
- 99.90% 99.86% tchain_edit tchain_edit [.] f3
99.86% _start
__libc_start_main
generic_start_main
main
f1
- f2
f3
System-wide mode:
$perf record --call-graph lbr -a -- taskset -c 0 ./tchain_edit
- 99.88% 99.82% tchain_edit tchain_edit [.] f3
- 62.02% main
f1
f2
f3
- 28.83% f1
- f2
f3
- 28.83% f1
- f2
f3
- 8.88% generic_start_main
main
f1
f2
f3
It isn't practical to simply allocate the data for system-wide event in
CPU context structure for all tasks. We have no idea which CPU a task
will be scheduled to. The duplicated LBR data has to be maintained on
every CPU context structure. That's a huge waste. Otherwise, the LBR
data still lost if the task is scheduled to another CPU.
Save the pmu specific data in task_struct. The size of pmu specific data
is 788 bytes for LBR call stack. Usually, the overall amount of threads
doesn't exceed a few thousands. For 10K threads, keeping LBR data would
consume additional ~8MB. The additional space will only be allocated
during LBR call stack monitoring. It will be released when the
monitoring is finished.
Furthermore, moving task_ctx_data from perf_event_context to task_struct
can reduce complexity and make things clearer. E.g. perf doesn't need to
swap task_ctx_data on optimized context switch path.
This patch set is just the first step. There could be other
optimization/extension on top of this patch set. E.g. for cgroup
profiling, perf just needs to save/store the LBR call stack information
for tasks in specific cgroup. That could reduce the additional space.
Also, the LBR call stack can be available for software events, or allow
even debugging use cases, like LBRs on crash later.
Because of the alignment requirement of Intel Arch LBR, the Kmem cache
is used to allocate the PMU specific data. It's required when child task
allocates the space. Save it in struct perf_ctx_data.
The refcount in struct perf_ctx_data is used to track the users of pmu
specific data.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Link: https://lore.kernel.org/r/20250314172700.438923-1-kan.liang@linux.intel.com
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Tao Chen
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c96fff391c |
perf/ring_buffer: Allow the EPOLLRDNORM flag for poll
The poll man page says POLLRDNORM is equivalent to POLLIN. For poll(),
it seems that if user sets pollfd with POLLRDNORM in userspace, perf_poll
will not return until timeout even if perf_output_wakeup called,
whereas POLLIN returns.
Fixes: 76369139ceb9 ("perf: Split up buffer handling from core code")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314030036.2543180-1-chen.dylane@linux.dev
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Namhyung Kim
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f4b07fd62d |
perf/core: Use POLLHUP for pinned events in error
Pinned performance events can enter an error state when they fail to be scheduled in the context due to a failed constraint or some other conflict or condition. In error state these events won't generate any samples anymore and are silently ignored until they are recovered by PERF_EVENT_IOC_ENABLE, or the condition can also change so that they can be scheduled in. Tooling should be allowed to know about the state change, but currently there's no mechanism to notify tooling when events enter an error state. One way to do this is to issue a POLLHUP event to poll(2) to handle this. Reading events in an error state would return 0 (EOF) and it matches to the behavior of POLLHUP according to the man page. Tooling should remove the fd of the event from pollfd after getting POLLHUP, otherwise it'll be returned repeatedly. [ mingo: Clarified the changelog ] Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250317061745.1777584-1-namhyung@kernel.org |