f0be83d542
1428 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
David Gow
|
4b18cb3f74 |
perf/hw_breakpoint: test: Skip the test if dependencies unmet
Running the test currently fails on non-SMP systems, despite being enabled by default. This means that running the test with: ./tools/testing/kunit/kunit.py run --arch x86_64 hw_breakpoint results in every hw_breakpoint test failing with: # test_one_cpu: failed to initialize: -22 not ok 1 - test_one_cpu Instead, use kunit_skip(), which will mark the test as skipped, and give a more comprehensible message: ok 1 - test_one_cpu # SKIP not enough cpus This makes it more obvious that the test is not suited to the test environment, and so wasn't run, rather than having run and failed. Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Latypov <dlatypov@google.com> Acked-by: Marco Elver <elver@google.com> Link: https://lore.kernel.org/r/20221026141040.1609203-1-davidgow@google.com |
||
James Clark
|
4b66ff46f2 |
perf: Fix missing raw data on tracepoint events
Since commit |
||
Peter Zijlstra
|
ca6c21327c |
perf: Fix missing SIGTRAPs
Marco reported:
Due to the implementation of how SIGTRAP are delivered if
perf_event_attr::sigtrap is set, we've noticed 3 issues:
1. Missing SIGTRAP due to a race with event_sched_out() (more
details below).
2. Hardware PMU events being disabled due to returning 1 from
perf_event_overflow(). The only way to re-enable the event is
for user space to first "properly" disable the event and then
re-enable it.
3. The inability to automatically disable an event after a
specified number of overflows via PERF_EVENT_IOC_REFRESH.
The worst of the 3 issues is problem (1), which occurs when a
pending_disable is "consumed" by a racing event_sched_out(), observed
as follows:
CPU0 | CPU1
--------------------------------+---------------------------
__perf_event_overflow() |
perf_event_disable_inatomic() |
pending_disable = CPU0 | ...
| _perf_event_enable()
| event_function_call()
| task_function_call()
| /* sends IPI to CPU0 */
<IPI> | ...
__perf_event_enable() +---------------------------
ctx_resched()
task_ctx_sched_out()
ctx_sched_out()
group_sched_out()
event_sched_out()
pending_disable = -1
</IPI>
<IRQ-work>
perf_pending_event()
perf_pending_event_disable()
/* Fails to send SIGTRAP because no pending_disable! */
</IRQ-work>
In the above case, not only is that particular SIGTRAP missed, but also
all future SIGTRAPs because 'event_limit' is not reset back to 1.
To fix, rework pending delivery of SIGTRAP via IRQ-work by introduction
of a separate 'pending_sigtrap', no longer using 'event_limit' and
'pending_disable' for its delivery.
Additionally; and different to Marco's proposed patch:
- recognise that pending_disable effectively duplicates oncpu for
the case where it is set. As such, change the irq_work handler to
use ->oncpu to target the event and use pending_* as boolean toggles.
- observe that SIGTRAP targets the ctx->task, so the context switch
optimization that carries contexts between tasks is invalid. If
the irq_work were delayed enough to hit after a context switch the
SIGTRAP would be delivered to the wrong task.
- observe that if the event gets scheduled out
(rotation/migration/context-switch/...) the irq-work would be
insufficient to deliver the SIGTRAP when the event gets scheduled
back in (the irq-work might still be pending on the old CPU).
Therefore have event_sched_out() convert the pending sigtrap into a
task_work which will deliver the signal at return_to_user.
Fixes:
|
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Linus Torvalds
|
27bc50fc90 |
- Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam R. Howlett. An overlapping range-based tree for vmas. It it apparently slight more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com). This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU= =xfWx -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ... |
||
|
Linus Torvalds
|
3871d93b82 |
Perf events updates for v6.1:
- PMU driver updates:
- Add AMD Last Branch Record Extension Version 2 (LbrExtV2)
feature support for Zen 4 processors.
- Extend the perf ABI to provide branch speculation information,
if available, and use this on CPUs that have it (eg. LbrExtV2).
- Improve Intel PEBS TSC timestamp handling & integration.
- Add Intel Raptor Lake S CPU support.
- Add 'perf mem' and 'perf c2c' memory profiling support on
AMD CPUs by utilizing IBS tagged load/store samples.
- Clean up & optimize various x86 PMU details.
- HW breakpoints:
- Big rework to optimize the code for systems with hundreds of CPUs and
thousands of breakpoints:
- Replace the nr_bp_mutex global mutex with the bp_cpuinfo_sem
per-CPU rwsem that is read-locked during most of the key operations.
- Improve the O(#cpus * #tasks) logic in toggle_bp_slot()
and fetch_bp_busy_slots().
- Apply micro-optimizations & cleanups.
- Misc cleanups & enhancements.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
"PMU driver updates:
- Add AMD Last Branch Record Extension Version 2 (LbrExtV2) feature
support for Zen 4 processors.
- Extend the perf ABI to provide branch speculation information, if
available, and use this on CPUs that have it (eg. LbrExtV2).
- Improve Intel PEBS TSC timestamp handling & integration.
- Add Intel Raptor Lake S CPU support.
- Add 'perf mem' and 'perf c2c' memory profiling support on AMD CPUs
by utilizing IBS tagged load/store samples.
- Clean up & optimize various x86 PMU details.
HW breakpoints:
- Big rework to optimize the code for systems with hundreds of CPUs
and thousands of breakpoints:
- Replace the nr_bp_mutex global mutex with the bp_cpuinfo_sem
per-CPU rwsem that is read-locked during most of the key
operations.
- Improve the O(#cpus * #tasks) logic in toggle_bp_slot() and
fetch_bp_busy_slots().
- Apply micro-optimizations & cleanups.
- Misc cleanups & enhancements"
* tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
perf/hw_breakpoint: Annotate tsk->perf_event_mutex vs ctx->mutex
perf: Fix pmu_filter_match()
perf: Fix lockdep_assert_event_ctx()
perf/x86/amd/lbr: Adjust LBR regardless of filtering
perf/x86/utils: Fix uninitialized var in get_branch_type()
perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file
perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR
perf/x86/amd: Support PERF_SAMPLE_ADDR
perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT}
perf/x86/amd: Support PERF_SAMPLE_DATA_SRC
perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions
perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO}
perf/x86/uncore: Add new Raptor Lake S support
perf/x86/cstate: Add new Raptor Lake S support
perf/x86/msr: Add new Raptor Lake S support
perf/x86: Add new Raptor Lake S support
bpf: Check flags for branch stack in bpf_read_branch_records helper
perf, hw_breakpoint: Fix use-after-free if perf_event_open() fails
perf: Use sample_flags for raw_data
perf: Use sample_flags for addr
...
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Peter Zijlstra
|
82aad7ff7a |
perf/hw_breakpoint: Annotate tsk->perf_event_mutex vs ctx->mutex
Perf fuzzer gifted a lockdep splat:
perf_event_init_context()
mutex_lock(parent_ctx->mutex); (B)
inherit_task_group()
inherit_group()
inherit_event()
perf_event_alloc()
perf_try_init_event() := hw_breakpoint_event_init()
register_perf_hw_breakpoint()
mutex_lock(child->perf_event_mutex); (A)
Which is against the normal (documented) order. Now, this is a false
positive in that child is not published yet, but also inherited events
never end up on ->perf_event_list.
Annotate this one away.
Fixes:
|
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Peter Zijlstra
|
7be51cc1c6 |
perf: Fix pmu_filter_match()
Mark reported that the new for_each_sibling_event() assertion triggers
in pmu_filter_match() -- which isn't always called with IRQs disabled
or ctx->mutex held.
Fixes:
|
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Zach O'Keefe
|
34488399fa |
mm/madvise: add file and shmem support to MADV_COLLAPSE
Add support for MADV_COLLAPSE to collapse shmem-backed and file-backed memory into THPs (requires CONFIG_READ_ONLY_THP_FOR_FS=y). On success, the backing memory will be a hugepage. For the memory range and process provided, the page tables will synchronously have a huge pmd installed, mapping the THP. Other mappings of the file extent mapped by the memory range may be added to a set of entries that khugepaged will later process and attempt update their page tables to map the THP by a pmd. This functionality unlocks two important uses: (1) Immediately back executable text by THPs. Current support provided by CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large system which might impair services from serving at their full rated load after (re)starting. Tricks like mremap(2)'ing text onto anonymous memory to immediately realize iTLB performance prevents page sharing and demand paging, both of which increase steady state memory footprint. Now, we can have the best of both worlds: Peak upfront performance and lower RAM footprints. (2) userfaultfd-based live migration of virtual machines satisfy UFFD faults by fetching native-sized pages over the network (to avoid latency of transferring an entire hugepage). However, after guest memory has been fully copied to the new host, MADV_COLLAPSE can be used to immediately increase guest performance. Since khugepaged is single threaded, this change now introduces possibility of collapse contexts racing in file collapse path. There a important few places to consider: (1) hpage_collapse_scan_file(), when we xas_pause() and drop RCU. We could have the memory collapsed out from under us, but the next xas_for_each() iteration will correctly pick up the hugepage. The hugepage might not be up to date (insofar as copying of small page contents might not have completed - the page still may be locked), but regardless what small page index we were iterating over, we'll find the hugepage and identify it as a suitably aligned compound page of order HPAGE_PMD_ORDER. In khugepaged path, we locklessly check the value of the pmd, and only add it to deferred collapse array if we find pmd mapping pte table. This is fine, since other values that could have raced in right afterwards denote failure, or that the memory was successfully collapsed, so we don't need further processing. In madvise path, we'll take mmap_lock() in write to serialize against page table updates and will know what to do based on the true value of the pmd: recheck all ptes if we point to a pte table, directly install the pmd, if the pmd has been cleared, but memory not yet faulted, or nothing at all if we find a huge pmd. It's worth putting emphasis here on how we treat the none pmd here. If khugepaged has processed this mm's page tables already, it will have left the pmd cleared (ready for refault by the process). Depending on the VMA flags and sysfs settings, amount of RAM on the machine, and the current load, could be a relatively common occurrence - and as such is one we'd like to handle successfully in MADV_COLLAPSE. When we see the none pmd in collapse_pte_mapped_thp(), we've locked mmap_lock in write and checked (a) huepaged_vma_check() to see if the backing memory is appropriate still, along with VMA sizing and appropriate hugepage alignment within the file, and (b) we've found a hugepage head of order HPAGE_PMD_ORDER at the offset in the file mapped by our hugepage-aligned virtual address. Even though the common-case is likely race with khugepaged, given these checks (regardless how we got here - we could be operating on a completely different file than originally checked in hpage_collapse_scan_file() for all we know) it should be safe to directly make the pmd a huge pmd pointing to this hugepage. (2) collapse_file() is mostly serialized on the same file extent by lock sequence: | lock hupepage | lock mapping->i_pages | lock 1st page | unlock mapping->i_pages | <page checks> | lock mapping->i_pages | page_ref_freeze(3) | xas_store(hugepage) | unlock mapping->i_pages | page_ref_unfreeze(1) | unlock 1st page V unlock hugepage Once a context (who already has their fresh hugepage locked) locks mapping->i_pages exclusively, it will hold said lock until it locks the first page, and it will hold that lock until the after the hugepage has been added to the page cache (and will unlock the hugepage after page table update, though that isn't important here). A racing context that loses the race for mapping->i_pages will then lose the race to locking the first page. Here - depending on how far the other racing context has gotten - we might find the new hugepage (in which case we'll exit cleanly when we check PageTransCompound()), or we'll find the "old" 1st small page (in which we'll exit cleanly when we discover unexpected refcount of 2 after isolate_lru_page()). This is assuming we are able to successfully lock the page we find - in shmem path, we could just fail the trylock and exit cleanly anyways. Failure path in collapse_file() is similar: once we hold lock on 1st small page, we are serialized against other collapse contexts. Before the 1st small page is unlocked, we add it back to the pagecache and unfreeze the refcount appropriately. Contexts who lost the race to the 1st small page will then find the same 1st small page with the correct refcount and will be able to proceed. [zokeefe@google.com: don't check pmd value twice in collapse_pte_mapped_thp()] Link: https://lkml.kernel.org/r/20220927033854.477018-1-zokeefe@google.com [shy828301@gmail.com: Delete hugepage_vma_revalidate_anon(), remove check for multi-add in khugepaged_add_pte_mapped_thp()] Link: https://lore.kernel.org/linux-mm/CAHbLzkrtpM=ic7cYAHcqkubah5VTR8N5=k5RT8MTvv5rN1Y91w@mail.gmail.com/ Link: https://lkml.kernel.org/r/20220907144521.3115321-4-zokeefe@google.com Link: https://lkml.kernel.org/r/20220922224046.1143204-4-zokeefe@google.com Signed-off-by: Zach O'Keefe <zokeefe@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Chris Kennelly <ckennelly@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <songliubraving@fb.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
|
82e66bf761 |
uprobes: use new_folio in __replace_page()
Saves several calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-57-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
|
5fcd079af9 |
uprobes: use folios more widely in __replace_page()
Remove a few hidden calls to compound_head(). Link: https://lkml.kernel.org/r/20220902194653.1739778-45-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ravi Bangoria
|
5b26af6d2b |
perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR
IBS_DC_PHYSADDR provides the physical data address for the tagged load/ store operation. Populate perf sample physical address using it. Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220928095805.596-7-ravi.bangoria@amd.com |
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Marco Elver
|
4674ffe2fc |
perf, hw_breakpoint: Fix use-after-free if perf_event_open() fails
Local testing revealed that we can trigger a use-after-free during
rhashtable lookup as follows:
| BUG: KASAN: use-after-free in memcmp lib/string.c:757
| Read of size 8 at addr ffff888107544dc0 by task perf-rhltable-n/1293
|
| CPU: 0 PID: 1293 Comm: perf-rhltable-n Not tainted 6.0.0-rc3-00014-g85260862789c #46
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
| Call Trace:
| <TASK>
| memcmp lib/string.c:757
| rhashtable_compare include/linux/rhashtable.h:577 [inline]
| __rhashtable_lookup include/linux/rhashtable.h:602 [inline]
| rhltable_lookup include/linux/rhashtable.h:688 [inline]
| task_bp_pinned kernel/events/hw_breakpoint.c:324
| toggle_bp_slot kernel/events/hw_breakpoint.c:462
| __release_bp_slot kernel/events/hw_breakpoint.c:631 [inline]
| release_bp_slot kernel/events/hw_breakpoint.c:639
| register_perf_hw_breakpoint kernel/events/hw_breakpoint.c:742
| hw_breakpoint_event_init kernel/events/hw_breakpoint.c:976
| perf_try_init_event kernel/events/core.c:11261
| perf_init_event kernel/events/core.c:11325 [inline]
| perf_event_alloc kernel/events/core.c:11619
| __do_sys_perf_event_open kernel/events/core.c:12157
| do_syscall_x64 arch/x86/entry/common.c:50 [inline]
| do_syscall_64 arch/x86/entry/common.c:80
| entry_SYSCALL_64_after_hwframe
| </TASK>
|
| Allocated by task 1292:
| perf_event_alloc kernel/events/core.c:11505
| __do_sys_perf_event_open kernel/events/core.c:12157
| do_syscall_x64 arch/x86/entry/common.c:50 [inline]
| do_syscall_64 arch/x86/entry/common.c:80
| entry_SYSCALL_64_after_hwframe
|
| Freed by task 1292:
| perf_event_alloc kernel/events/core.c:11716
| __do_sys_perf_event_open kernel/events/core.c:12157
| do_syscall_x64 arch/x86/entry/common.c:50 [inline]
| do_syscall_64 arch/x86/entry/common.c:80
| entry_SYSCALL_64_after_hwframe
|
| The buggy address belongs to the object at ffff888107544c00
| which belongs to the cache perf_event of size 1352
| The buggy address is located 448 bytes inside of
| 1352-byte region [ffff888107544c00, ffff888107545148)
This happens because the first perf_event_open() managed to reserve a HW
breakpoint slot, however, later fails for other reasons and returns. The
second perf_event_open() runs concurrently, and during rhltable_lookup()
looks up an entry which is being freed: since rhltable_lookup() may run
concurrently (under the RCU read lock) with rhltable_remove(), we may
end up with a stale entry, for which memory may also have already been
freed when being accessed.
To fix, only free the failed perf_event after an RCU grace period. This
allows subsystems that store references to an event to always access it
concurrently under the RCU read lock, even if initialization will fail.
Given failure is unlikely and a slow-path, turning the immediate free
into a call_rcu()-wrapped free does not affect performance elsewhere.
Fixes:
|
||
Namhyung Kim
|
838d9bb62d |
perf: Use sample_flags for raw_data
Use the new sample_flags to indicate whether the raw data field is filled by the PMU driver. Although it could check with the NULL, follow the same rule with other fields. Remove the raw field from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220921220032.2858517-2-namhyung@kernel.org |
||
|
Namhyung Kim
|
7b08463015 |
perf: Use sample_flags for addr
Use the new sample_flags to indicate whether the addr field is filled by the PMU driver. As most PMU drivers pass 0, it can set the flag only if it has a non-zero value. And use 0 in perf_sample_output() if it's not filled already. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220921220032.2858517-1-namhyung@kernel.org |
||
|
Matthew Wilcox (Oracle)
|
fcb72a585a |
perf: use VMA iterator
The VMA iterator is faster than the linked list and removing the linked list will shrink the vm_area_struct. Link: https://lkml.kernel.org/r/20220906194824.2110408-48-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jules Irenge
|
dca6344d7a |
perf/core: Convert snprintf() to scnprintf()
Coccinelle reports a warning:
WARNING: use scnprintf or sprintf
This LWN article explains the rationale for this change:
https: //lwn.net/Articles/69419/
Ie. snprintf() returns what *would* be the resulting length,
while scnprintf() returns the actual length.
Adding to that, there has also been some slow migration from snprintf to scnprintf,
here's the shift in usage in the past 3.5 years, in all fs/ files:
v5.0 v6.0-rc6
--------------------------------------
snprintf() uses: 63 213
scnprintf() uses: 374 186
No intended change in behavior.
[ mingo: Improved the changelog & reviewed the usage sites. ]
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
Namhyung Kim
|
16817ad7e8 |
perf/bpf: Always use perf callchains if exist
If the perf_event has PERF_SAMPLE_CALLCHAIN, BPF can use it for stack trace. The problematic cases like PEBS and IBS already handled in the PMU driver and they filled the callchain info in the sample data. For others, we can call perf_callchain() before the BPF handler. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220908214104.3851807-2-namhyung@kernel.org |
||
|
Namhyung Kim
|
3749d33e51 |
perf: Use sample_flags for callchain
So that it can call perf_callchain() only if needed. Historically it used __PERF_SAMPLE_CALLCHAIN_EARLY but we can do that with sample_flags in the struct perf_sample_data. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220908214104.3851807-1-namhyung@kernel.org |
||
|
Peter Zijlstra
|
f3c0eba287 |
perf: Add a few assertions
While auditing
|
||
Anshuman Khandual
|
03b02db93b |
perf: Consolidate branch sample filter helpers
Besides the branch type filtering requests, 'event.attr.branch_sample_type' also contains various flags indicating which additional information should be captured, along with the base branch record. These flags help configure the underlying hardware, and capture the branch records appropriately when required e.g after PMU interrupt. But first, this moves an existing helper perf_sample_save_hw_index() into the header before adding some more helpers for other branch sample filter flags. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220906084414.396220-1-anshuman.khandual@arm.com |
||
Kan Liang
|
ee9db0e14b |
perf: Use sample_flags for txn
Use the new sample_flags to indicate whether the txn field is filled by the PMU driver. Remove the txn field from the perf_sample_data_init() to minimize the number of cache lines touched. 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/20220901130959.1285717-7-kan.liang@linux.intel.com |
||
|
Kan Liang
|
e16fd7f2cb |
perf: Use sample_flags for data_src
Use the new sample_flags to indicate whether the data_src field is filled by the PMU driver. Remove the data_src field from the perf_sample_data_init() to minimize the number of cache lines touched. 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/20220901130959.1285717-6-kan.liang@linux.intel.com |
||
|
Kan Liang
|
2abe681da0 |
perf: Use sample_flags for weight
Use the new sample_flags to indicate whether the weight field is filled by the PMU driver. Remove the weight field from the perf_sample_data_init() to minimize the number of cache lines touched. 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/20220901130959.1285717-5-kan.liang@linux.intel.com |
||
|
Kan Liang
|
a9a931e266 |
perf: Use sample_flags for branch stack
Use the new sample_flags to indicate whether the branch stack is filled by the PMU driver. Remove the br_stack from the perf_sample_data_init() to minimize the number of cache lines touched. 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/20220901130959.1285717-4-kan.liang@linux.intel.com |
||
|
Kan Liang
|
3aac580d5c |
perf: Add sample_flags to indicate the PMU-filled sample data
On some platforms, some data e.g., timestamps, can be retrieved from the PMU driver. Usually, the data from the PMU driver is more accurate. The current perf kernel should output the PMU-filled sample data if it's available. To check the availability of the PMU-filled sample data, the current perf kernel initializes the related fields in the perf_sample_data_init(). When outputting a sample, the perf checks whether the field is updated by the PMU driver. If yes, the updated value will be output. If not, the perf uses an SW way to calculate the value or just outputs the initialized value if an SW way is unavailable either. With more and more data being provided by the PMU driver, more fields has to be initialized in the perf_sample_data_init(). That will increase the number of cache lines touched in perf_sample_data_init() and be harmful to the performance. Add new "sample_flags" to indicate the PMU-filled sample data. The PMU driver should set the corresponding PERF_SAMPLE_ flag when the field is updated. The initialization of the corresponding field is not required anymore. The following patches will make use of it and remove the corresponding fields from the perf_sample_data_init(), which will further minimize the number of cache lines touched. Only clear the sample flags that have already been done by the PMU driver in the perf_prepare_sample() for the PERF_RECORD_SAMPLE. For the other PERF_RECORD_ event type, the sample data is not available. 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/20220901130959.1285717-2-kan.liang@linux.intel.com |
||
Yang Jihong
|
6b959ba22d |
perf/core: Fix reentry problem in perf_output_read_group()
perf_output_read_group may respond to IPI request of other cores and invoke
__perf_install_in_context function. As a result, hwc configuration is modified.
causing inconsistency and unexpected consequences.
Interrupts are not disabled when perf_output_read_group reads PMU counter.
In this case, IPI request may be received from other cores.
As a result, PMU configuration is modified and an error occurs when
reading PMU counter:
CPU0 CPU1
__se_sys_perf_event_open
perf_install_in_context
perf_output_read_group smp_call_function_single
for_each_sibling_event(sub, leader) { generic_exec_single
if ((sub != event) && remote_function
(sub->state == PERF_EVENT_STATE_ACTIVE)) |
<enter IPI handler: __perf_install_in_context> <----RAISE IPI-----+
__perf_install_in_context
ctx_resched
event_sched_out
armpmu_del
...
hwc->idx = -1; // event->hwc.idx is set to -1
...
<exit IPI>
sub->pmu->read(sub);
armpmu_read
armv8pmu_read_counter
armv8pmu_read_hw_counter
int idx = event->hw.idx; // idx = -1
u64 val = armv8pmu_read_evcntr(idx);
u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30
read_pmevcntrn(counter) // undefined instruction
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com
|
||
|
Marco Elver
|
ecdfb8896f |
perf/hw_breakpoint: Optimize toggle_bp_slot() for CPU-independent task targets
We can still see that a majority of the time is spent hashing task pointers:
...
16.98% [kernel] [k] rhashtable_jhash2
...
Doing the bookkeeping in toggle_bp_slots() is currently O(#cpus),
calling task_bp_pinned() for each CPU, even if task_bp_pinned() is
CPU-independent. The reason for this is to update the per-CPU
'tsk_pinned' histogram.
To optimize the CPU-independent case to O(1), keep a separate
CPU-independent 'tsk_pinned_all' histogram.
The major source of complexity are transitions between "all
CPU-independent task breakpoints" and "mixed CPU-independent and
CPU-dependent task breakpoints". The code comments list all cases that
require handling.
After this optimization:
| $> perf bench -r 100 breakpoint thread -b 4 -p 128 -t 512
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 100 threads with 4 breakpoints and 128 parallelism
| Total time: 1.758 [sec]
|
| 34.336621 usecs/op
| 4395.087500 usecs/op/cpu
38.08% [kernel] [k] queued_spin_lock_slowpath
10.81% [kernel] [k] smp_cfm_core_cond
3.01% [kernel] [k] update_sg_lb_stats
2.58% [kernel] [k] osq_lock
2.57% [kernel] [k] llist_reverse_order
1.45% [kernel] [k] find_next_bit
1.21% [kernel] [k] flush_tlb_func_common
1.01% [kernel] [k] arch_install_hw_breakpoint
Showing that the time spent hashing keys has become insignificant.
With the given benchmark parameters, that's an improvement of 12%
compared with the old O(#cpus) version.
And finally, using the less aggressive parameters from the preceding
changes, we now observe:
| $> perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 0.067 [sec]
|
| 35.292187 usecs/op
| 2258.700000 usecs/op/cpu
Which is an improvement of 12% compared to without the histogram
optimizations (baseline is 40 usecs/op). This is now on par with the
theoretical ideal (constraints disabled), and only 12% slower than no
breakpoints at all.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-15-elver@google.com
|
||
|
Marco Elver
|
9b1933b864 |
perf/hw_breakpoint: Optimize max_bp_pinned_slots() for CPU-independent task targets
Running the perf benchmark with (note: more aggressive parameters vs.
preceding changes, but same 256 CPUs host):
| $> perf bench -r 100 breakpoint thread -b 4 -p 128 -t 512
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 100 threads with 4 breakpoints and 128 parallelism
| Total time: 1.989 [sec]
|
| 38.854160 usecs/op
| 4973.332500 usecs/op/cpu
20.43% [kernel] [k] queued_spin_lock_slowpath
18.75% [kernel] [k] osq_lock
16.98% [kernel] [k] rhashtable_jhash2
8.34% [kernel] [k] task_bp_pinned
4.23% [kernel] [k] smp_cfm_core_cond
3.65% [kernel] [k] bcmp
2.83% [kernel] [k] toggle_bp_slot
1.87% [kernel] [k] find_next_bit
1.49% [kernel] [k] __reserve_bp_slot
We can see that a majority of the time is now spent hashing task
pointers to index into task_bps_ht in task_bp_pinned().
Obtaining the max_bp_pinned_slots() for CPU-independent task targets
currently is O(#cpus), and calls task_bp_pinned() for each CPU, even if
the result of task_bp_pinned() is CPU-independent.
The loop in max_bp_pinned_slots() wants to compute the maximum slots
across all CPUs. If task_bp_pinned() is CPU-independent, we can do so by
obtaining the max slots across all CPUs and adding task_bp_pinned().
To do so in O(1), use a bp_slots_histogram for CPU-pinned slots.
After this optimization:
| $> perf bench -r 100 breakpoint thread -b 4 -p 128 -t 512
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 100 threads with 4 breakpoints and 128 parallelism
| Total time: 1.930 [sec]
|
| 37.697832 usecs/op
| 4825.322500 usecs/op/cpu
19.13% [kernel] [k] queued_spin_lock_slowpath
18.21% [kernel] [k] rhashtable_jhash2
15.46% [kernel] [k] osq_lock
6.27% [kernel] [k] toggle_bp_slot
5.91% [kernel] [k] task_bp_pinned
5.05% [kernel] [k] smp_cfm_core_cond
1.78% [kernel] [k] update_sg_lb_stats
1.36% [kernel] [k] llist_reverse_order
1.34% [kernel] [k] find_next_bit
1.19% [kernel] [k] bcmp
Suggesting that time spent in task_bp_pinned() has been reduced.
However, we're still hashing too much, which will be addressed in the
subsequent change.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-14-elver@google.com
|
||
|
Marco Elver
|
16db2839a5 |
perf/hw_breakpoint: Introduce bp_slots_histogram
Factor out the existing `atomic_t count[N]` into its own struct called 'bp_slots_histogram', to generalize and make its intent clearer in preparation of reusing elsewhere. The basic idea of bucketing "total uses of N slots" resembles a histogram, so calling it such seems most intuitive. No functional change. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-13-elver@google.com |
||
|
Marco Elver
|
0912037fec |
perf/hw_breakpoint: Reduce contention with large number of tasks
While optimizing task_bp_pinned()'s runtime complexity to O(1) on
average helps reduce time spent in the critical section, we still suffer
due to serializing everything via 'nr_bp_mutex'. Indeed, a profile shows
that now contention is the biggest issue:
95.93% [kernel] [k] osq_lock
0.70% [kernel] [k] mutex_spin_on_owner
0.22% [kernel] [k] smp_cfm_core_cond
0.18% [kernel] [k] task_bp_pinned
0.18% [kernel] [k] rhashtable_jhash2
0.15% [kernel] [k] queued_spin_lock_slowpath
when running the breakpoint benchmark with (system with 256 CPUs):
| $> perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 0.207 [sec]
|
| 108.267188 usecs/op
| 6929.100000 usecs/op/cpu
The main concern for synchronizing the breakpoint constraints data is
that a consistent snapshot of the per-CPU and per-task data is observed.
The access pattern is as follows:
1. If the target is a task: the task's pinned breakpoints are counted,
checked for space, and then appended to; only bp_cpuinfo::cpu_pinned
is used to check for conflicts with CPU-only breakpoints;
bp_cpuinfo::tsk_pinned are incremented/decremented, but otherwise
unused.
2. If the target is a CPU: bp_cpuinfo::cpu_pinned are counted, along
with bp_cpuinfo::tsk_pinned; after a successful check, cpu_pinned is
incremented. No per-task breakpoints are checked.
Since rhltable safely synchronizes insertions/deletions, we can allow
concurrency as follows:
1. If the target is a task: independent tasks may update and check the
constraints concurrently, but same-task target calls need to be
serialized; since bp_cpuinfo::tsk_pinned is only updated, but not
checked, these modifications can happen concurrently by switching
tsk_pinned to atomic_t.
2. If the target is a CPU: access to the per-CPU constraints needs to
be serialized with other CPU-target and task-target callers (to
stabilize the bp_cpuinfo::tsk_pinned snapshot).
We can allow the above concurrency by introducing a per-CPU constraints
data reader-writer lock (bp_cpuinfo_sem), and per-task mutexes (reuses
task_struct::perf_event_mutex):
1. If the target is a task: acquires perf_event_mutex, and acquires
bp_cpuinfo_sem as a reader. The choice of percpu-rwsem minimizes
contention in the presence of many read-lock but few write-lock
acquisitions: we assume many orders of magnitude more task target
breakpoints creations/destructions than CPU target breakpoints.
2. If the target is a CPU: acquires bp_cpuinfo_sem as a writer.
With these changes, contention with thousands of tasks is reduced to the
point where waiting on locking no longer dominates the profile:
| $> perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 0.077 [sec]
|
| 40.201563 usecs/op
| 2572.900000 usecs/op/cpu
21.54% [kernel] [k] task_bp_pinned
20.18% [kernel] [k] rhashtable_jhash2
6.81% [kernel] [k] toggle_bp_slot
5.47% [kernel] [k] queued_spin_lock_slowpath
3.75% [kernel] [k] smp_cfm_core_cond
3.48% [kernel] [k] bcmp
On this particular setup that's a speedup of 2.7x.
We're also getting closer to the theoretical ideal performance through
optimizations in hw_breakpoint.c -- constraints accounting disabled:
| perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 0.067 [sec]
|
| 35.286458 usecs/op
| 2258.333333 usecs/op/cpu
Which means the current implementation is ~12% slower than the
theoretical ideal.
For reference, performance without any breakpoints:
| $> bench -r 30 breakpoint thread -b 0 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 0 breakpoints and 64 parallelism
| Total time: 0.060 [sec]
|
| 31.365625 usecs/op
| 2007.400000 usecs/op/cpu
On a system with 256 CPUs, the theoretical ideal is only ~12% slower
than no breakpoints at all; the current implementation is ~28% slower.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-12-elver@google.com
|
||
|
Marco Elver
|
24198ad373 |
perf/hw_breakpoint: Remove useless code related to flexible breakpoints
Flexible breakpoints have never been implemented, with bp_cpuinfo::flexible always being 0. Unfortunately, they still occupy 4 bytes in each bp_cpuinfo and bp_busy_slots, as well as computing the max flexible count in fetch_bp_busy_slots(). This again causes suboptimal code generation, when we always know that `!!slots.flexible` will be 0. Just get rid of the flexible "placeholder" and remove all real code related to it. Make a note in the comment related to the constraints algorithm but don't remove them from the algorithm, so that if in future flexible breakpoints need supporting, it should be trivial to revive them (along with reverting this change). Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-9-elver@google.com |
||
|
Marco Elver
|
9caf87be11 |
perf/hw_breakpoint: Make hw_breakpoint_weight() inlinable
Due to being a __weak function, hw_breakpoint_weight() will cause the
compiler to always emit a call to it. This generates unnecessarily bad
code (register spills etc.) for no good reason; in fact it appears in
profiles of `perf bench -r 100 breakpoint thread -b 4 -p 128 -t 512`:
...
0.70% [kernel] [k] hw_breakpoint_weight
...
While a small percentage, no architecture defines its own
hw_breakpoint_weight() nor are there users outside hw_breakpoint.c,
which makes the fact it is currently __weak a poor choice.
Change hw_breakpoint_weight()'s definition to follow a similar protocol
to hw_breakpoint_slots(), such that if <asm/hw_breakpoint.h> defines
hw_breakpoint_weight(), we'll use it instead.
The result is that it is inlined and no longer shows up in profiles.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-8-elver@google.com
|
||
|
Marco Elver
|
be3f152568 |
perf/hw_breakpoint: Optimize constant number of breakpoint slots
Optimize internal hw_breakpoint state if the architecture's number of breakpoint slots is constant. This avoids several kmalloc() calls and potentially unnecessary failures if the allocations fail, as well as subtly improves code generation and cache locality. The protocol is that if an architecture defines hw_breakpoint_slots via the preprocessor, it must be constant and the same for all types. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-7-elver@google.com |
||
|
Marco Elver
|
db5f6f8531 |
perf/hw_breakpoint: Mark data __ro_after_init
Mark read-only data after initialization as __ro_after_init. While we are here, turn 'constraints_initialized' into a bool. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-6-elver@google.com |
||
|
Marco Elver
|
0370dc314d |
perf/hw_breakpoint: Optimize list of per-task breakpoints
On a machine with 256 CPUs, running the recently added perf breakpoint
benchmark results in:
| $> perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 236.418 [sec]
|
| 123134.794271 usecs/op
| 7880626.833333 usecs/op/cpu
The benchmark tests inherited breakpoint perf events across many
threads.
Looking at a perf profile, we can see that the majority of the time is
spent in various hw_breakpoint.c functions, which execute within the
'nr_bp_mutex' critical sections which then results in contention on that
mutex as well:
37.27% [kernel] [k] osq_lock
34.92% [kernel] [k] mutex_spin_on_owner
12.15% [kernel] [k] toggle_bp_slot
11.90% [kernel] [k] __reserve_bp_slot
The culprit here is task_bp_pinned(), which has a runtime complexity of
O(#tasks) due to storing all task breakpoints in the same list and
iterating through that list looking for a matching task. Clearly, this
does not scale to thousands of tasks.
Instead, make use of the "rhashtable" variant "rhltable" which stores
multiple items with the same key in a list. This results in average
runtime complexity of O(1) for task_bp_pinned().
With the optimization, the benchmark shows:
| $> perf bench -r 30 breakpoint thread -b 4 -p 64 -t 64
| # Running 'breakpoint/thread' benchmark:
| # Created/joined 30 threads with 4 breakpoints and 64 parallelism
| Total time: 0.208 [sec]
|
| 108.422396 usecs/op
| 6939.033333 usecs/op/cpu
On this particular setup that's a speedup of ~1135x.
While one option would be to make task_struct a breakpoint list node,
this would only further bloat task_struct for infrequently used data.
Furthermore, after all optimizations in this series, there's no evidence
it would result in better performance: later optimizations make the time
spent looking up entries in the hash table negligible (we'll reach the
theoretical ideal performance i.e. no constraints).
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20220829124719.675715-5-elver@google.com
|
||
|
Marco Elver
|
089cdcb0cd |
perf/hw_breakpoint: Clean up headers
Clean up headers: - Remove unused <linux/kallsyms.h> - Remove unused <linux/kprobes.h> - Remove unused <linux/module.h> - Remove unused <linux/smp.h> - Add <linux/export.h> for EXPORT_SYMBOL_GPL(). - Add <linux/mutex.h> for mutex. - Sort alphabetically. - Move <linux/hw_breakpoint.h> to top to test it compiles on its own. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-4-elver@google.com |
||
|
Marco Elver
|
c5b81449f9 |
perf/hw_breakpoint: Provide hw_breakpoint_is_used() and use in test
Provide hw_breakpoint_is_used() to check if breakpoints are in use on the system. Use it in the KUnit test to verify the global state before and after a test case. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-3-elver@google.com |
||
|
Marco Elver
|
724c299c6a |
perf/hw_breakpoint: Add KUnit test for constraints accounting
Add KUnit test for hw_breakpoint constraints accounting, with various interesting mixes of breakpoint targets (some care was taken to catch interesting corner cases via bug-injection). The test cannot be built as a module because it requires access to hw_breakpoint_slots(), which is not inlinable or exported on all architectures. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20220829124719.675715-2-elver@google.com |
||
|
Linus Torvalds
|
592d8362bc |
Misc fixes to kprobes and the faddr2line script, plus a cleanup.
Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmLuu5MRHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1gFbA//ZppMR0/26/d+KqhdbVND6wtuTzGb5krZ m3QynlRQ+x7CZJNJeiNSTo/Dup/KwBUpJFT5sKLtpfOQILxlEt0hdYMiD+/oxgxd K0Vb0QrZhwFCju+OpcDAVlWNcQ5P8MMdoGUkOr5ekZ9FFalabW+bVUuM2Yf0Cok8 e20MGoZa2jcd+AZkp9jPUtCTURpW3Ew1WcVuJIgLH3EUMNrQNiPdia6xBzFyOPAw L0G14RDkd/POGF90dUGY1Ta4WeQCNYp2Rgu5DLo6l3eJJ/oeqoIUBUoNRT9AOJHH 0SVNHkrrNlRJe9HD/Jdc6RVBMM+FFNU4rw1uxOPU2OtG0MyMsj39Nzw+xmvB9QsG mwnMoeeDOJmFRnAyhETe4meR5mA8cPQDoNNlHL51I9JTJTUutIrfd+gQIgVgYrM2 oVfLW7Y0Eew8qYbAd2kfGnFNHDSH90RHG4beTz4zW3y4shembKhiPU7bgJ8lkke7 u4NgDOE+qTmtC1DznuV4Av8/27W6OMt/j1IWeR78IN7YBko99Ekog3zsWrAJgA/E Y08JVrUpUU47tMl4uC9Y0AUvm1Tb2ZyDqcdlEEzF9txtdNa6cAJtJkPaO6nUrr4+ qLCbhBBADP+oQNESi6vRHRmxmk5Z/m2ybfnAuYNNraWY01Imp4kNvLFvB01ARGaF Qin7dCjqz+E= =S41z -----END PGP SIGNATURE----- Merge tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes to kprobes and the faddr2line script, plus a cleanup" * tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix ';;' typo scripts/faddr2line: Add CONFIG_DEBUG_INFO check scripts/faddr2line: Fix vmlinux detection on arm64 x86/kprobes: Update kcb status flag after singlestepping kprobes: Forbid probing on trampoline and BPF code areas |
||
Slark Xiao
|
99643bab36 |
perf/core: Fix ';;' typo
Remove double ';;'. Signed-off-by: Slark Xiao <slark_xiao@163.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220720091220.14200-1-slark_xiao@163.com |
||
|
Linus Torvalds
|
f86d1fbbe7 |
Networking changes for 6.0.
Core
----
- Refactor the forward memory allocation to better cope with memory
pressure with many open sockets, moving from a per socket cache to
a per-CPU one
- Replace rwlocks with RCU for better fairness in ping, raw sockets
and IP multicast router.
- Network-side support for IO uring zero-copy send.
- A few skb drop reason improvements, including codegen the source file
with string mapping instead of using macro magic.
- Rename reference tracking helpers to a more consistent
netdev_* schema.
- Adapt u64_stats_t type to address load/store tearing issues.
- Refine debug helper usage to reduce the log noise caused by bots.
BPF
---
- Improve socket map performance, avoiding skb cloning on read
operation.
- Add support for 64 bits enum, to match types exposed by kernel.
- Introduce support for sleepable uprobes program.
- Introduce support for enum textual representation in libbpf.
- New helpers to implement synproxy with eBPF/XDP.
- Improve loop performances, inlining indirect calls when
possible.
- Removed all the deprecated libbpf APIs.
- Implement new eBPF-based LSM flavor.
- Add type match support, which allow accurate queries to the
eBPF used types.
- A few TCP congetsion control framework usability improvements.
- Add new infrastructure to manipulate CT entries via eBPF programs.
- Allow for livepatch (KLP) and BPF trampolines to attach to the same
kernel function.
Protocols
---------
- Introduce per network namespace lookup tables for unix sockets,
increasing scalability and reducing contention.
- Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support.
- Add support to forciby close TIME_WAIT TCP sockets via user-space
tools.
- Significant performance improvement for the TLS 1.3 receive path,
both for zero-copy and not-zero-copy.
- Support for changing the initial MTPCP subflow priority/backup
status
- Introduce virtually contingus buffers for sockets over RDMA,
to cope better with memory pressure.
- Extend CAN ethtool support with timestamping capabilities
- Refactor CAN build infrastructure to allow building only the needed
features.
Driver API
----------
- Remove devlink mutex to allow parallel commands on multiple links.
- Add support for pause stats in distributed switch.
- Implement devlink helpers to query and flash line cards.
- New helper for phy mode to register conversion.
New hardware / drivers
----------------------
- Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro.
- Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch.
- Ethernet DSA driver for the Microchip LAN937x switch.
- Ethernet PHY driver for the Aquantia AQR113C EPHY.
- CAN driver for the OBD-II ELM327 interface.
- CAN driver for RZ/N1 SJA1000 CAN controller.
- Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device.
Drivers
-------
- Intel Ethernet NICs:
- i40e: add support for vlan pruning
- i40e: add support for XDP framented packets
- ice: improved vlan offload support
- ice: add support for PPPoE offload
- Mellanox Ethernet (mlx5)
- refactor packet steering offload for performance and scalability
- extend support for TC offload
- refactor devlink code to clean-up the locking schema
- support stacked vlans for bridge offloads
- use TLS objects pool to improve connection rate
- Netronome Ethernet NICs (nfp):
- extend support for IPv6 fields mangling offload
- add support for vepa mode in HW bridge
- better support for virtio data path acceleration (VDPA)
- enable TSO by default
- Microsoft vNIC driver (mana)
- add support for XDP redirect
- Others Ethernet drivers:
- bonding: add per-port priority support
- microchip lan743x: extend phy support
- Fungible funeth: support UDP segmentation offload and XDP xmit
- Solarflare EF100: add support for virtual function representors
- MediaTek SoC: add XDP support
- Mellanox Ethernet/IB switch (mlxsw):
- dropped support for unreleased H/W (XM router).
- improved stats accuracy
- unified bridge model coversion improving scalability
(parts 1-6)
- support for PTP in Spectrum-2 asics
- Broadcom PHYs
- add PTP support for BCM54210E
- add support for the BCM53128 internal PHY
- Marvell Ethernet switches (prestera):
- implement support for multicast forwarding offload
- Embedded Ethernet switches:
- refactor OcteonTx MAC filter for better scalability
- improve TC H/W offload for the Felix driver
- refactor the Microchip ksz8 and ksz9477 drivers to share
the probe code (parts 1, 2), add support for phylink
mac configuration
- Other WiFi:
- Microchip wilc1000: diable WEP support and enable WPA3
- Atheros ath10k: encapsulation offload support
Old code removal:
- Neterion vxge ethernet driver: this is untouched since more than
10 years.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking changes from Paolo Abeni:
"Core:
- Refactor the forward memory allocation to better cope with memory
pressure with many open sockets, moving from a per socket cache to
a per-CPU one
- Replace rwlocks with RCU for better fairness in ping, raw sockets
and IP multicast router.
- Network-side support for IO uring zero-copy send.
- A few skb drop reason improvements, including codegen the source
file with string mapping instead of using macro magic.
- Rename reference tracking helpers to a more consistent netdev_*
schema.
- Adapt u64_stats_t type to address load/store tearing issues.
- Refine debug helper usage to reduce the log noise caused by bots.
BPF:
- Improve socket map performance, avoiding skb cloning on read
operation.
- Add support for 64 bits enum, to match types exposed by kernel.
- Introduce support for sleepable uprobes program.
- Introduce support for enum textual representation in libbpf.
- New helpers to implement synproxy with eBPF/XDP.
- Improve loop performances, inlining indirect calls when possible.
- Removed all the deprecated libbpf APIs.
- Implement new eBPF-based LSM flavor.
- Add type match support, which allow accurate queries to the eBPF
used types.
- A few TCP congetsion control framework usability improvements.
- Add new infrastructure to manipulate CT entries via eBPF programs.
- Allow for livepatch (KLP) and BPF trampolines to attach to the same
kernel function.
Protocols:
- Introduce per network namespace lookup tables for unix sockets,
increasing scalability and reducing contention.
- Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support.
- Add support to forciby close TIME_WAIT TCP sockets via user-space
tools.
- Significant performance improvement for the TLS 1.3 receive path,
both for zero-copy and not-zero-copy.
- Support for changing the initial MTPCP subflow priority/backup
status
- Introduce virtually contingus buffers for sockets over RDMA, to
cope better with memory pressure.
- Extend CAN ethtool support with timestamping capabilities
- Refactor CAN build infrastructure to allow building only the needed
features.
Driver API:
- Remove devlink mutex to allow parallel commands on multiple links.
- Add support for pause stats in distributed switch.
- Implement devlink helpers to query and flash line cards.
- New helper for phy mode to register conversion.
New hardware / drivers:
- Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro.
- Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch.
- Ethernet DSA driver for the Microchip LAN937x switch.
- Ethernet PHY driver for the Aquantia AQR113C EPHY.
- CAN driver for the OBD-II ELM327 interface.
- CAN driver for RZ/N1 SJA1000 CAN controller.
- Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device.
Drivers:
- Intel Ethernet NICs:
- i40e: add support for vlan pruning
- i40e: add support for XDP framented packets
- ice: improved vlan offload support
- ice: add support for PPPoE offload
- Mellanox Ethernet (mlx5)
- refactor packet steering offload for performance and scalability
- extend support for TC offload
- refactor devlink code to clean-up the locking schema
- support stacked vlans for bridge offloads
- use TLS objects pool to improve connection rate
- Netronome Ethernet NICs (nfp):
- extend support for IPv6 fields mangling offload
- add support for vepa mode in HW bridge
- better support for virtio data path acceleration (VDPA)
- enable TSO by default
- Microsoft vNIC driver (mana)
- add support for XDP redirect
- Others Ethernet drivers:
- bonding: add per-port priority support
- microchip lan743x: extend phy support
- Fungible funeth: support UDP segmentation offload and XDP xmit
- Solarflare EF100: add support for virtual function representors
- MediaTek SoC: add XDP support
- Mellanox Ethernet/IB switch (mlxsw):
- dropped support for unreleased H/W (XM router).
- improved stats accuracy
- unified bridge model coversion improving scalability (parts 1-6)
- support for PTP in Spectrum-2 asics
- Broadcom PHYs
- add PTP support for BCM54210E
- add support for the BCM53128 internal PHY
- Marvell Ethernet switches (prestera):
- implement support for multicast forwarding offload
- Embedded Ethernet switches:
- refactor OcteonTx MAC filter for better scalability
- improve TC H/W offload for the Felix driver
- refactor the Microchip ksz8 and ksz9477 drivers to share the
probe code (parts 1, 2), add support for phylink mac
configuration
- Other WiFi:
- Microchip wilc1000: diable WEP support and enable WPA3
- Atheros ath10k: encapsulation offload support
Old code removal:
- Neterion vxge ethernet driver: this is untouched since more than 10 years"
* tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1890 commits)
doc: sfp-phylink: Fix a broken reference
wireguard: selftests: support UML
wireguard: allowedips: don't corrupt stack when detecting overflow
wireguard: selftests: update config fragments
wireguard: ratelimiter: use hrtimer in selftest
net/mlx5e: xsk: Discard unaligned XSK frames on striding RQ
net: usb: ax88179_178a: Bind only to vendor-specific interface
selftests: net: fix IOAM test skip return code
net: usb: make USB_RTL8153_ECM non user configurable
net: marvell: prestera: remove reduntant code
octeontx2-pf: Reduce minimum mtu size to 60
net: devlink: Fix missing mutex_unlock() call
net/tls: Remove redundant workqueue flush before destroy
net: txgbe: Fix an error handling path in txgbe_probe()
net: dsa: Fix spelling mistakes and cleanup code
Documentation: devlink: add add devlink-selftests to the table of contents
dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock
net: ionic: fix error check for vlan flags in ionic_set_nic_features()
net: ice: fix error NETIF_F_HW_VLAN_CTAG_FILTER check in ice_vsi_sync_fltr()
nfp: flower: add support for tunnel offload without key ID
...
|
||
|
Linus Torvalds
|
63e6053add |
Perf events updates for this cycle are:
- Fix Intel Alder Lake PEBS memory access latency & data source profiling info bugs. - Use Intel large-PEBS hardware feature in more circumstances, to reduce PMI overhead & reduce sampling data. - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI variant, which tells tooling the exact number of samples lost. - Add new IBS register bits definitions. - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements. Signed-off-by: Ingo Molnar <mingo@kernel.org> -----BEGIN PGP SIGNATURE----- iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmLn5MARHG1pbmdvQGtl cm5lbC5vcmcACgkQEnMQ0APhK1jAWA/+N48UX35dD0u3k5S2zdYJRHzQkdbivVGc dOuCB3XTJYneaSI5byQkI4Xo8LUuMbF4q2Zi3/+XhTaqn2zYPP65D6ACL5hU9Shh F95TnLWbedIaxSJmjMCsWDlwBob8WgtLhokWvyq+ks66BqaDoBKHRtn+2fi0rwZb MbuN0199Gx/EicWEOeUGBSxoeKbjSix0BApqy+CuXC0DC3+3iwIPk4dbNfHXpHYs nqxjQKhJnoxdlgjiOY3UuYhdCZl1cuQFIu2Ce1N2nXCAgR2FeQD7ZqtcaA2TnsAO 9BwRfLljavzHhOoz0zALR42kF+eOcnH5K9pIBx7py9Hjdmdsx88fUCovWK34MdG5 KTuqiMWNLIUvoP9WBjl7wUtl2+vcjr9XwgCdneOO+zoNsk44qSRyer1RpEP6D9UM e9HvdXBVRzhnIhK9NYugeLJ+3nxvFL+OLvc3ZfUrtm04UzeetCBxMlvMv3y021V7 0fInZjhzh4Dz2tJgNlG7AKXkXlsHlyj6/BH9uKc9wVokK+94g5mbspxW8R4gKPr2 l06pYB7ttSpp26sq9vl5ASHO0rniiYAPsQcr7Ko3y72mmp6kfIe/HzYNhCEvgYe2 6JJ8F9kPgRuKr0CwGvUzxFwBC7PJR80zUtZkRCIpV+rgxQcNmK5YXp/KQFIjQqkI rJfEaDOshl0= =DqaA -----END PGP SIGNATURE----- Merge tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf events updates from Ingo Molnar: - Fix Intel Alder Lake PEBS memory access latency & data source profiling info bugs. - Use Intel large-PEBS hardware feature in more circumstances, to reduce PMI overhead & reduce sampling data. - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI variant, which tells tooling the exact number of samples lost. - Add new IBS register bits definitions. - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements. * tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/ibs: Add new IBS register bits into header perf/x86/intel: Fix PEBS data source encoding for ADL perf/x86/intel: Fix PEBS memory access info encoding for ADL perf/core: Add a new read format to get a number of lost samples perf/x86/amd/uncore: Add PerfMonV2 RDPMC assignments perf/x86/amd/uncore: Add PerfMonV2 DF event format perf/x86/amd/uncore: Detect available DF counters perf/x86/amd/uncore: Use attr_update for format attributes perf/x86/amd/uncore: Use dynamic events array x86/events/intel/ds: Enable large PEBS for PERF_SAMPLE_WEIGHT_TYPE |
||
Jakub Kicinski
|
6e0e846ee2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|
Peter Zijlstra
|
68e3c69803 |
perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()
Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():
CPU1 CPU2
perf_mmap_close(e2)
if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0
detach_rest = true
ioctl(e1, IOC_SET_OUTPUT, e2)
perf_event_set_output(e1, e2)
...
list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry)
ring_buffer_attach(e, NULL);
// e1 isn't yet added and
// therefore not detached
ring_buffer_attach(e1, e2->rb)
list_add_rcu(&e1->rb_entry,
&e2->rb->event_list)
After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:
again:
mutex_lock(&e->mmap_mutex);
if (event->rb) {
...
if (!atomic_inc_not_zero(&e->rb->mmap_count)) {
...
mutex_unlock(&e->mmap_mutex);
goto again;
}
}
The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach
in perf_event_set_output() holds e1->mmap_mutex. As such there is no
serialization to avoid this race.
Change perf_event_set_output() to take both e1->mmap_mutex and
e2->mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.
Fixes:
|
||
|
Namhyung Kim
|
119a784c81 |
perf/core: Add a new read format to get a number of lost samples
Sometimes we want to know an accurate number of samples even if it's lost. Currenlty PERF_RECORD_LOST is generated for a ring-buffer which might be shared with other events. So it's hard to know per-event lost count. Add event->lost_samples field and PERF_FORMAT_LOST to retrieve it from userspace. Original-patch-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220616180623.1358843-1-namhyung@kernel.org |
||
|
Jakub Kicinski
|
9fb424c4c2 |
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-06-17
We've added 72 non-merge commits during the last 15 day(s) which contain
a total of 92 files changed, 4582 insertions(+), 834 deletions(-).
The main changes are:
1) Add 64 bit enum value support to BTF, from Yonghong Song.
2) Implement support for sleepable BPF uprobe programs, from Delyan Kratunov.
3) Add new BPF helpers to issue and check TCP SYN cookies without binding to a
socket especially useful in synproxy scenarios, from Maxim Mikityanskiy.
4) Fix libbpf's internal USDT address translation logic for shared libraries as
well as uprobe's symbol file offset calculation, from Andrii Nakryiko.
5) Extend libbpf to provide an API for textual representation of the various
map/prog/attach/link types and use it in bpftool, from Daniel Müller.
6) Provide BTF line info for RV64 and RV32 JITs, and fix a put_user bug in the
core seen in 32 bit when storing BPF function addresses, from Pu Lehui.
7) Fix libbpf's BTF pointer size guessing by adding a list of various aliases
for 'long' types, from Douglas Raillard.
8) Fix bpftool to readd setting rlimit since probing for memcg-based accounting
has been unreliable and caused a regression on COS, from Quentin Monnet.
9) Fix UAF in BPF cgroup's effective program computation triggered upon BPF link
detachment, from Tadeusz Struk.
10) Fix bpftool build bootstrapping during cross compilation which was pointing
to the wrong AR process, from Shahab Vahedi.
11) Fix logic bug in libbpf's is_pow_of_2 implementation, from Yuze Chi.
12) BPF hash map optimization to avoid grabbing spinlocks of all CPUs when there
is no free element. Also add a benchmark as reproducer, from Feng Zhou.
13) Fix bpftool's codegen to bail out when there's no BTF, from Michael Mullin.
14) Various minor cleanup and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits)
bpf: Fix bpf_skc_lookup comment wrt. return type
bpf: Fix non-static bpf_func_proto struct definitions
selftests/bpf: Don't force lld on non-x86 architectures
selftests/bpf: Add selftests for raw syncookie helpers in TC mode
bpf: Allow the new syncookie helpers to work with SKBs
selftests/bpf: Add selftests for raw syncookie helpers
bpf: Add helpers to issue and check SYN cookies in XDP
bpf: Allow helpers to accept pointers with a fixed size
bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie
selftests/bpf: add tests for sleepable (uk)probes
libbpf: add support for sleepable uprobe programs
bpf: allow sleepable uprobe programs to attach
bpf: implement sleepable uprobes by chaining gps
bpf: move bpf_prog to bpf.h
libbpf: Fix internal USDT address translation logic for shared libraries
samples/bpf: Check detach prog exist or not in xdp_fwd
selftests/bpf: Avoid skipping certain subtests
selftests/bpf: Fix test_varlen verification failure with latest llvm
bpftool: Do not check return value from libbpf_set_strict_mode()
Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"
...
====================
Link: https://lore.kernel.org/r/20220617220836.7373-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Delyan Kratunov
|
64ad7556c7 |
bpf: allow sleepable uprobe programs to attach
uprobe and kprobe programs have the same program type, KPROBE, which is currently not allowed to load sleepable programs. To avoid adding a new UPROBE type, instead allow sleepable KPROBE programs to load and defer the is-it-actually-a-uprobe-program check to attachment time, where there's already validation of the corresponding perf_event. A corollary of this patch is that you can now load a sleepable kprobe program but cannot attach it. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Delyan Kratunov <delyank@fb.com> Link: https://lore.kernel.org/r/fcd44a7cd204f372f6bb03ef794e829adeaef299.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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|
Linus Torvalds
|
fa11c28046 |
Two small perf updates:
- Make the ICL event constraints match reality - Remove a unused local variable -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmKcc6gTHHRnbHhAbGlu dXRyb25peC5kZQAKCRCmGPVMDXSYoZA7EAC6zZqvX+yJn3c5C3rQDOyCJ74Zvawc IG3t35ADS7IbZm0rOjSdZz89V5Gz8bzMsjYHdADQw1URajuXvVwLkCFG5oY0owyo XSlAYBnMOYQ0nnZ/PqKO91oieyU0z3dkP5BHpFF0ZcqD4fSZaFvwtx2kneXDJBlw WIQqRYgRaKBRt+FTwmcm2ow3+afO9TY0oleOSbc0dokbGhwCO9hsuP0LwyMtA374 zGPzsHdHizvDUq+gEW5ZnmjAhrXqNnK6QOLZQukRlP4I6bnQlCkB9mtu/k6jEaAo xl4o0VvB0y4NoSNPBSvrIHF360nIsSMqIBV0TPv4lI1B+p4/Dr9cQTn3J+J43x+c SqpDs2JH22S6zhjgDPKt+hAyaKkPJan+E4dy33sbT8zlrwODGPcso6WdpdWQshQg WJU1HhHq6PU1vcKJEoQmagipFN70O3elufVsW5+qddJ3tmPM2ghET5Ib1E2+Odrk NICXW2aduogQL+9H62SOdXwRcuF6kUrO0J8I7l61eyGxr/XpOlg0vljgNgS7HxF8 IyrrfuNsj+p5SpVmg9LRwE9+vG5xi9lpGWoYmlp2RPTzOn0OfLtYI2rto70s6i6F xjvIaer1ulW4OP4cvHZd6VTVUl8ZE5lRM4VqdTFgzFpR7AuBMW+PVXcF5l4ubtZp x2NC+i0/3sQ7JQ== =ZK+2 -----END PGP SIGNATURE----- Merge tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: - Make the ICL event constraints match reality - Remove a unused local variable * tag 'perf-urgent-2022-06-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Remove unused local variable perf/x86/intel: Fix event constraints for ICL |
||
Haowen Bai
|
8b4dd2d862 |
perf/core: Remove unused local variable
Drop LIST_HEAD() where the variable it declares is never used. Compiler probably never warned us, because the LIST_HEAD() initializer is technically 'usage'. [ mingo: Tweak changelog. ] Signed-off-by: Haowen Bai <baihaowen@meizu.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/1653645835-29206-1-git-send-email-baihaowen@meizu.com |
||
|
Linus Torvalds
|
98931dd95f |
Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
Johannes Weiner has arranged for zswap memory use to be tracked and
managed on a per-cgroup basis.
Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
enablement of the recent huge page vmemmap optimization feature.
Baolin Wang contributes a series to fix some issues around hugetlb
pagetable invalidation.
Zhenwei Pi has fixed some interactions between hwpoisoned pages and
virtualization.
Tong Tiangen has enabled the use of the presently x86-only
page_table_check debugging feature on arm64 and riscv.
David Vernet has done some fixup work on the memcg selftests.
Peter Xu has taught userfaultfd to handle write protection faults against
shmem- and hugetlbfs-backed files.
More DAMON development from SeongJae Park - adding online tuning of the
feature and support for monitoring of fixed virtual address ranges. Also
easier discovery of which monitoring operations are available.
Nadav Amit has done some optimization of TLB flushing during mprotect().
Neil Brown continues to labor away at improving our swap-over-NFS support.
David Hildenbrand has some fixes to anon page COWing versus
get_user_pages().
Peng Liu fixed some errors in the core hugetlb code.
Joao Martins has reduced the amount of memory consumed by device-dax's
compound devmaps.
Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
Muchun Song has found and fixed some errors in the TLB flushing of
transparent hugepages.
Roman Gushchin has done more work on the memcg selftests.
And, of course, many smaller fixes and cleanups. Notably, the customary
million cleanup serieses from Miaohe Lin.
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Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Almost all of MM here. A few things are still getting finished off,
reviewed, etc.
- Yang Shi has improved the behaviour of khugepaged collapsing of
readonly file-backed transparent hugepages.
- Johannes Weiner has arranged for zswap memory use to be tracked and
managed on a per-cgroup basis.
- Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
runtime enablement of the recent huge page vmemmap optimization
feature.
- Baolin Wang contributes a series to fix some issues around hugetlb
pagetable invalidation.
- Zhenwei Pi has fixed some interactions between hwpoisoned pages and
virtualization.
- Tong Tiangen has enabled the use of the presently x86-only
page_table_check debugging feature on arm64 and riscv.
- David Vernet has done some fixup work on the memcg selftests.
- Peter Xu has taught userfaultfd to handle write protection faults
against shmem- and hugetlbfs-backed files.
- More DAMON development from SeongJae Park - adding online tuning of
the feature and support for monitoring of fixed virtual address
ranges. Also easier discovery of which monitoring operations are
available.
- Nadav Amit has done some optimization of TLB flushing during
mprotect().
- Neil Brown continues to labor away at improving our swap-over-NFS
support.
- David Hildenbrand has some fixes to anon page COWing versus
get_user_pages().
- Peng Liu fixed some errors in the core hugetlb code.
- Joao Martins has reduced the amount of memory consumed by
device-dax's compound devmaps.
- Some cleanups of the arch-specific pagemap code from Anshuman
Khandual.
- Muchun Song has found and fixed some errors in the TLB flushing of
transparent hugepages.
- Roman Gushchin has done more work on the memcg selftests.
... and, of course, many smaller fixes and cleanups. Notably, the
customary million cleanup serieses from Miaohe Lin"
* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
mm: kfence: use PAGE_ALIGNED helper
selftests: vm: add the "settings" file with timeout variable
selftests: vm: add "test_hmm.sh" to TEST_FILES
selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
selftests: vm: add migration to the .gitignore
selftests/vm/pkeys: fix typo in comment
ksm: fix typo in comment
selftests: vm: add process_mrelease tests
Revert "mm/vmscan: never demote for memcg reclaim"
mm/kfence: print disabling or re-enabling message
include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
mm: fix a potential infinite loop in start_isolate_page_range()
MAINTAINERS: add Muchun as co-maintainer for HugeTLB
zram: fix Kconfig dependency warning
mm/shmem: fix shmem folio swapoff hang
cgroup: fix an error handling path in alloc_pagecache_max_30M()
mm: damon: use HPAGE_PMD_SIZE
tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
nodemask.h: fix compilation error with GCC12
...
|