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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
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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
...
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Pull page cache updates from Matthew Wilcox:
- Appoint myself page cache maintainer
- Fix how scsicam uses the page cache
- Use the memalloc_nofs_save() API to replace AOP_FLAG_NOFS
- Remove the AOP flags entirely
- Remove pagecache_write_begin() and pagecache_write_end()
- Documentation updates
- Convert several address_space operations to use folios:
- is_dirty_writeback
- readpage becomes read_folio
- releasepage becomes release_folio
- freepage becomes free_folio
- Change filler_t to require a struct file pointer be the first
argument like ->read_folio
* tag 'folio-5.19' of git://git.infradead.org/users/willy/pagecache: (107 commits)
nilfs2: Fix some kernel-doc comments
Appoint myself page cache maintainer
fs: Remove aops->freepage
secretmem: Convert to free_folio
nfs: Convert to free_folio
orangefs: Convert to free_folio
fs: Add free_folio address space operation
fs: Convert drop_buffers() to use a folio
fs: Change try_to_free_buffers() to take a folio
jbd2: Convert release_buffer_page() to use a folio
jbd2: Convert jbd2_journal_try_to_free_buffers to take a folio
reiserfs: Convert release_buffer_page() to use a folio
fs: Remove last vestiges of releasepage
ubifs: Convert to release_folio
reiserfs: Convert to release_folio
orangefs: Convert to release_folio
ocfs2: Convert to release_folio
nilfs2: Remove comment about releasepage
nfs: Convert to release_folio
jfs: Convert to release_folio
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
"Platform PMU changes:
- x86/intel:
- Add new Intel Alder Lake and Raptor Lake support
- x86/amd:
- AMD Zen4 IBS extensions support
- Add AMD PerfMonV2 support
- Add AMD Fam19h Branch Sampling support
Generic changes:
- signal: Deliver SIGTRAP on perf event asynchronously if blocked
Perf instrumentation can be driven via SIGTRAP, but this causes a
problem when SIGTRAP is blocked by a task & terminate the task.
Allow user-space to request these signals asynchronously (after
they get unblocked) & also give the information to the signal
handler when this happens:
"To give user space the ability to clearly distinguish
synchronous from asynchronous signals, introduce
siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for
flags in case more binary information is required in future).
The resolution to the problem is then to (a) no longer force the
signal (avoiding the terminations), but (b) tell user space via
si_perf_flags if the signal was synchronous or not, so that such
signals can be handled differently (e.g. let user space decide
to ignore or consider the data imprecise). "
- Unify/standardize the /sys/devices/cpu/events/* output format.
- Misc fixes & cleanups"
* tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
perf/x86/amd/core: Fix reloading events for SVM
perf/x86/amd: Run AMD BRS code only on supported hw
perf/x86/amd: Fix AMD BRS period adjustment
perf/x86/amd: Remove unused variable 'hwc'
perf/ibs: Fix comment
perf/amd/ibs: Advertise zen4_ibs_extensions as pmu capability attribute
perf/amd/ibs: Add support for L3 miss filtering
perf/amd/ibs: Use ->is_visible callback for dynamic attributes
perf/amd/ibs: Cascade pmu init functions' return value
perf/x86/uncore: Add new Alder Lake and Raptor Lake support
perf/x86/uncore: Clean up uncore_pci_ids[]
perf/x86/cstate: Add new Alder Lake and Raptor Lake support
perf/x86/msr: Add new Alder Lake and Raptor Lake support
perf/x86: Add new Alder Lake and Raptor Lake support
perf/amd/ibs: Use interrupt regs ip for stack unwinding
perf/x86/amd/core: Add PerfMonV2 overflow handling
perf/x86/amd/core: Add PerfMonV2 counter control
perf/x86/amd/core: Detect available counters
perf/x86/amd/core: Detect PerfMonV2 support
x86/msr: Add PerfCntrGlobal* registers
...
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Norbert reported that it's possible to race sys_perf_event_open() such
that the looser ends up in another context from the group leader,
triggering many WARNs.
The move_group case checks for races against itself, but the
!move_group case doesn't, seemingly relying on the previous
group_leader->ctx == ctx check. However, that check is racy due to not
holding any locks at that time.
Therefore, re-check the result after acquiring locks and bailing
if they no longer match.
Additionally, clarify the not_move_group case from the
move_group-vs-move_group race.
Fixes: f63a8daa5812 ("perf: Fix event->ctx locking")
Reported-by: Norbert Slusarek <nslusarek@gmx.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Obtain the new INTEL_FAM6 stuff required.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
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New anonymous pages are always mapped natively: only THP/khugepaged code
maps a new compound anonymous page and passes "true". Otherwise, we're
just dealing with simple, non-compound pages.
Let's give the interface clearer semantics and document these. Remove the
PageTransCompound() sanity check from page_add_new_anon_rmap().
Link: https://lkml.kernel.org/r/20220428083441.37290-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Don Dutile <ddutile@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Liang Zhang <zhangliang5@huawei.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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With all implementations of aops->readpage converted to aops->read_folio,
we can stop checking whether it's set and remove the member from aops.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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Change all the callers of ->readpage to call ->read_folio in preference,
if it exists. This is a transitional duplication, and will be removed
by the end of the series.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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With SIGTRAP on perf events, we have encountered termination of
processes due to user space attempting to block delivery of SIGTRAP.
Consider this case:
<set up SIGTRAP on a perf event>
...
sigset_t s;
sigemptyset(&s);
sigaddset(&s, SIGTRAP | <and others>);
sigprocmask(SIG_BLOCK, &s, ...);
...
<perf event triggers>
When the perf event triggers, while SIGTRAP is blocked, force_sig_perf()
will force the signal, but revert back to the default handler, thus
terminating the task.
This makes sense for error conditions, but not so much for explicitly
requested monitoring. However, the expectation is still that signals
generated by perf events are synchronous, which will no longer be the
case if the signal is blocked and delivered later.
To give user space the ability to clearly distinguish synchronous from
asynchronous signals, introduce siginfo_t::si_perf_flags and
TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is
required in future).
The resolution to the problem is then to (a) no longer force the signal
(avoiding the terminations), but (b) tell user space via si_perf_flags
if the signal was synchronous or not, so that such signals can be
handled differently (e.g. let user space decide to ignore or consider
the data imprecise).
The alternative of making the kernel ignore SIGTRAP on perf events if
the signal is blocked may work for some usecases, but likely causes
issues in others that then have to revert back to interception of
sigprocmask() (which we want to avoid). [ A concrete example: when using
breakpoint perf events to track data-flow, in a region of code where
signals are blocked, data-flow can no longer be tracked accurately.
When a relevant asynchronous signal is received after unblocking the
signal, the data-flow tracking logic needs to know its state is
imprecise. ]
Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/20220404111204.935357-1-elver@google.com
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This problem can be reproduced with CONFIG_PERF_USE_VMALLOC enabled on
both x86_64 and aarch64 arch when using sysdig -B(using ebpf)[1].
sysdig -B works fine after rebuilding the kernel with
CONFIG_PERF_USE_VMALLOC disabled.
I tracked it down to the if condition event->rb->nr_pages != nr_pages
in perf_mmap is true when CONFIG_PERF_USE_VMALLOC is enabled where
event->rb->nr_pages = 1 and nr_pages = 2048 resulting perf_mmap to
return -EINVAL. This is because when CONFIG_PERF_USE_VMALLOC is
enabled, rb->nr_pages is always equal to 1.
Arch with CONFIG_PERF_USE_VMALLOC enabled by default:
arc/arm/csky/mips/sh/sparc/xtensa
Arch with CONFIG_PERF_USE_VMALLOC disabled by default:
x86_64/aarch64/...
Fix this problem by using data_page_nr()
[1] https://github.com/draios/sysdig
Fixes: 906010b2134e ("perf_event: Provide vmalloc() based mmap() backing")
Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220209145417.6495-1-xiezhipeng1@huawei.com
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When enable a cgroup event, cpuctx->cgrp setting is conditional
on the current task cgrp matching the event's cgroup, so have to
do it for every new event. It brings complexity but no advantage.
To keep it simple, this patch would always set cpuctx->cgrp
when enable the first cgroup event, and reset to NULL when disable
the last cgroup event.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220329154523.86438-5-zhouchengming@bytedance.com
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There is a race problem that can trigger WARN_ON_ONCE(cpuctx->cgrp)
in perf_cgroup_switch().
CPU1 CPU2
perf_cgroup_sched_out(prev, next)
cgrp1 = perf_cgroup_from_task(prev)
cgrp2 = perf_cgroup_from_task(next)
if (cgrp1 != cgrp2)
perf_cgroup_switch(prev, PERF_CGROUP_SWOUT)
cgroup_migrate_execute()
task->cgroups = ?
perf_cgroup_attach()
task_function_call(task, __perf_cgroup_move)
perf_cgroup_sched_in(prev, next)
cgrp1 = perf_cgroup_from_task(prev)
cgrp2 = perf_cgroup_from_task(next)
if (cgrp1 != cgrp2)
perf_cgroup_switch(next, PERF_CGROUP_SWIN)
__perf_cgroup_move()
perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN)
The commit a8d757ef076f ("perf events: Fix slow and broken cgroup
context switch code") want to skip perf_cgroup_switch() when the
perf_cgroup of "prev" and "next" are the same.
But task->cgroups can change in concurrent with context_switch()
in cgroup_migrate_execute(). If cgrp1 == cgrp2 in sched_out(),
cpuctx won't do sched_out. Then task->cgroups changed cause
cgrp1 != cgrp2 in sched_in(), cpuctx will do sched_in. So trigger
WARN_ON_ONCE(cpuctx->cgrp).
Even though __perf_cgroup_move() will be synchronized as the context
switch disables the interrupt, context_switch() still can see the
task->cgroups is changing in the middle, since task->cgroups changed
before sending IPI.
So we have to combine perf_cgroup_sched_in() into perf_cgroup_sched_out(),
unified into perf_cgroup_switch(), to fix the incosistency between
perf_cgroup_sched_out() and perf_cgroup_sched_in().
But we can't just compare prev->cgroups with next->cgroups to decide
whether to skip cpuctx sched_out/in since the prev->cgroups is changing
too. For example:
CPU1 CPU2
cgroup_migrate_execute()
prev->cgroups = ?
perf_cgroup_attach()
task_function_call(task, __perf_cgroup_move)
perf_cgroup_switch(task)
cgrp1 = perf_cgroup_from_task(prev)
cgrp2 = perf_cgroup_from_task(next)
if (cgrp1 != cgrp2)
cpuctx sched_out/in ...
task_function_call() will return -ESRCH
In the above example, prev->cgroups changing cause (cgrp1 == cgrp2)
to be true, so skip cpuctx sched_out/in. And later task_function_call()
would return -ESRCH since the prev task isn't running on cpu anymore.
So we would leave perf_events of the old prev->cgroups still sched on
the CPU, which is wrong.
The solution is that we should use cpuctx->cgrp to compare with
the next task's perf_cgroup. Since cpuctx->cgrp can only be changed
on local CPU, and we have irq disabled, we can read cpuctx->cgrp to
compare without holding ctx lock.
Fixes: a8d757ef076f ("perf events: Fix slow and broken cgroup context switch code")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220329154523.86438-4-zhouchengming@bytedance.com
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Since we use perf_cgroup_set_timestamp() to start cgroup time and
set active to 1, then use update_cgrp_time_from_cpuctx() to stop
cgroup time and set active to 0.
We can use info->active directly to check if cgroup is active.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220329154523.86438-3-zhouchengming@bytedance.com
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The current code pass task around for ctx_sched_in(), only
to get perf_cgroup of the task, then update the timestamp
of it and its ancestors and set them to active.
But we can use cpuctx->cgrp to get active perf_cgroup and
its ancestors since cpuctx->cgrp has been set before
ctx_sched_in().
This patch remove the task argument in ctx_sched_in()
and cleanup related code.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220329154523.86438-2-zhouchengming@bytedance.com
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It was reported that some perf event setup can make fork failed on
ARM64. It was the case of a group of mixed hw and sw events and it
failed in perf_event_init_task() due to armpmu_event_init().
The ARM PMU code checks if all the events in a group belong to the
same PMU except for software events. But it didn't set the event_caps
of inherited events and no longer identify them as software events.
Therefore the test failed in a child process.
A simple reproducer is:
$ perf stat -e '{cycles,cs,instructions}' perf bench sched messaging
# Running 'sched/messaging' benchmark:
perf: fork(): Invalid argument
The perf stat was fine but the perf bench failed in fork(). Let's
inherit the event caps from the parent.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20220328200112.457740-1-namhyung@kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull asm-generic updates from Arnd Bergmann:
"There are three sets of updates for 5.18 in the asm-generic tree:
- The set_fs()/get_fs() infrastructure gets removed for good.
This was already gone from all major architectures, but now we can
finally remove it everywhere, which loses some particularly tricky
and error-prone code. There is a small merge conflict against a
parisc cleanup, the solution is to use their new version.
- The nds32 architecture ends its tenure in the Linux kernel.
The hardware is still used and the code is in reasonable shape, but
the mainline port is not actively maintained any more, as all
remaining users are thought to run vendor kernels that would never
be updated to a future release.
- A series from Masahiro Yamada cleans up some of the uapi header
files to pass the compile-time checks"
* tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits)
nds32: Remove the architecture
uaccess: remove CONFIG_SET_FS
ia64: remove CONFIG_SET_FS support
sh: remove CONFIG_SET_FS support
sparc64: remove CONFIG_SET_FS support
lib/test_lockup: fix kernel pointer check for separate address spaces
uaccess: generalize access_ok()
uaccess: fix type mismatch warnings from access_ok()
arm64: simplify access_ok()
m68k: fix access_ok for coldfire
MIPS: use simpler access_ok()
MIPS: Handle address errors for accesses above CPU max virtual user address
uaccess: add generic __{get,put}_kernel_nofault
nios2: drop access_ok() check from __put_user()
x86: use more conventional access_ok() definition
x86: remove __range_not_ok()
sparc64: add __{get,put}_kernel_nofault()
nds32: fix access_ok() checks in get/put_user
uaccess: fix nios2 and microblaze get_user_8()
sparc64: fix building assembly files
...
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Pull folio updates from Matthew Wilcox:
- Rewrite how munlock works to massively reduce the contention on
i_mmap_rwsem (Hugh Dickins):
https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/
- Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
Hellwig):
https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/
- Convert GUP to use folios and make pincount available for order-1
pages. (Matthew Wilcox)
- Convert a few more truncation functions to use folios (Matthew
Wilcox)
- Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
Wilcox)
- Convert rmap_walk to use folios (Matthew Wilcox)
- Convert most of shrink_page_list() to use a folio (Matthew Wilcox)
- Add support for creating large folios in readahead (Matthew Wilcox)
* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
mm/damon: minor cleanup for damon_pa_young
selftests/vm/transhuge-stress: Support file-backed PMD folios
mm/filemap: Support VM_HUGEPAGE for file mappings
mm/readahead: Switch to page_cache_ra_order
mm/readahead: Align file mappings for non-DAX
mm/readahead: Add large folio readahead
mm: Support arbitrary THP sizes
mm: Make large folios depend on THP
mm: Fix READ_ONLY_THP warning
mm/filemap: Allow large folios to be added to the page cache
mm: Turn can_split_huge_page() into can_split_folio()
mm/vmscan: Convert pageout() to take a folio
mm/vmscan: Turn page_check_references() into folio_check_references()
mm/vmscan: Account large folios correctly
mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
mm/vmscan: Free non-shmem folios without splitting them
mm/rmap: Constify the rmap_walk_control argument
mm/rmap: Convert rmap_walk() to take a folio
mm: Turn page_anon_vma() into folio_anon_vma()
mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf event updates from Ingo Molnar:
- Fix address filtering for Intel/PT,ARM/CoreSight
- Enable Intel/PEBS format 5
- Allow more fixed-function counters for x86
- Intel/PT: Enable not recording Taken-Not-Taken packets
- Add a few branch-types
* tag 'perf-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Fix the build on !CONFIG_PHYS_ADDR_T_64BIT
perf: Add irq and exception return branch types
perf/x86/intel/uncore: Make uncore_discovery clean for 64 bit addresses
perf/x86/intel/pt: Add a capability and config bit for disabling TNTs
perf/x86/intel/pt: Add a capability and config bit for event tracing
perf/x86/intel: Increase max number of the fixed counters
KVM: x86: use the KVM side max supported fixed counter
perf/x86/intel: Enable PEBS format 5
perf/core: Allow kernel address filter when not filtering the kernel
perf/x86/intel/pt: Fix address filter config for 32-bit kernel
perf/core: Fix address filter parser for multiple filters
x86: Share definition of __is_canonical_address()
perf/x86/intel/pt: Relax address filter validation
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Instead of declaring a struct page_vma_mapped_walk directly,
use these helpers to allow us to transition to a PFN approach in the
following patches.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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There are no remaining callers of set_fs(), so CONFIG_SET_FS
can be removed globally, along with the thread_info field and
any references to it.
This turns access_ok() into a cheaper check against TASK_SIZE_MAX.
As CONFIG_SET_FS is now gone, drop all remaining references to
set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel().
Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes
Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic]
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Add vma argument to mlock_vma_page() and munlock_vma_page(), make them
inline functions which check (vma->vm_flags & VM_LOCKED) before calling
mlock_page() and munlock_page() in mm/mlock.c.
Add bool compound to mlock_vma_page() and munlock_vma_page(): this is
because we have understandable difficulty in accounting pte maps of THPs,
and if passed a PageHead page, mlock_page() and munlock_page() cannot
tell whether it's a pmd map to be counted or a pte map to be ignored.
Add vma arg to page_add_file_rmap() and page_remove_rmap(), like the
others, and use that to call mlock_vma_page() at the end of the page
adds, and munlock_vma_page() at the end of page_remove_rmap() (end or
beginning? unimportant, but end was easier for assertions in testing).
No page lock is required (although almost all adds happen to hold it):
delete the "Serialize with page migration" BUG_ON(!PageLocked(page))s.
Certainly page lock did serialize with page migration, but I'm having
difficulty explaining why that was ever important.
Mlock accounting on THPs has been hard to define, differed between anon
and file, involved PageDoubleMap in some places and not others, required
clear_page_mlock() at some points. Keep it simple now: just count the
pmds and ignore the ptes, there is no reason for ptes to undo pmd mlocks.
page_add_new_anon_rmap() callers unchanged: they have long been calling
lru_cache_add_inactive_or_unevictable(), which does its own VM_LOCKED
handling (it also checks for not VM_SPECIAL: I think that's overcautious,
and inconsistent with other checks, that mmap_region() already prevents
VM_LOCKED on VM_SPECIAL; but haven't quite convinced myself to change it).
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
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There's list corruption on cgrp_cpuctx_list. This happens on the
following path:
perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list)
cpu_ctx_sched_in
ctx_sched_in
ctx_pinned_sched_in
merge_sched_in
perf_cgroup_event_disable: remove the event from the list
Use list_for_each_entry_safe() to allow removing an entry during
iteration.
Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events")
Signed-off-by: Song Liu <song@kernel.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org
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The so-called 'kernel' address filter can also be useful for filtering
fixed addresses in user space. Allow that.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220131072453.2839535-6-adrian.hunter@intel.com
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Reset appropriate variables in the parser loop between parsing separate
filters, so that they do not interfere with parsing the next filter.
Fixes: 375637bc524952 ("perf/core: Introduce address range filtering")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220131072453.2839535-4-adrian.hunter@intel.com
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The intent has always been that perf_event_attr::sig_data should also be
modifiable along with PERF_EVENT_IOC_MODIFY_ATTRIBUTES, because it is
observable by user space if SIGTRAP on events is requested.
Currently only PERF_TYPE_BREAKPOINT is modifiable, and explicitly copies
relevant breakpoint-related attributes in hw_breakpoint_copy_attr().
This misses copying perf_event_attr::sig_data.
Since sig_data is not specific to PERF_TYPE_BREAKPOINT, introduce a
helper to copy generic event-type-independent attributes on
modification.
Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/20220131103407.1971678-1-elver@google.com
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The active cgroup events are managed in the per-cpu cgrp_cpuctx_list.
This list is only accessed from current cpu and not protected by any
locks. But from the commit ef54c1a476ae ("perf: Rework
perf_event_exit_event()"), it's possible to access (actually modify)
the list from another cpu.
In the perf_remove_from_context(), it can remove an event from the
context without an IPI when the context is not active. This is not
safe with cgroup events which can have some active events in the
context even if ctx->is_active is 0 at the moment. The target cpu
might be in the middle of list iteration at the same time.
If the event is enabled when it's about to be closed, it might call
perf_cgroup_event_disable() and list_del() with the cgrp_cpuctx_list
on a different cpu.
This resulted in a crash due to an invalid list pointer access during
the cgroup list traversal on the cpu which the event belongs to.
Let's fallback to IPI to access the cgrp_cpuctx_list from that cpu.
Similarly, perf_install_in_context() should use IPI for the cgroup
events too.
Fixes: ef54c1a476ae ("perf: Rework perf_event_exit_event()")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124195808.2252071-1-namhyung@kernel.org
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When using per-process mode and event inheritance is set to true,
forked processes will create a new perf events via inherit_event() ->
perf_event_alloc(). But these events will not have ring buffers
assigned to them. Any call to wakeup will be dropped if it's called on
an event with no ring buffer assigned because that's the object that
holds the wakeup list.
If the child event is disabled due to a call to
perf_aux_output_begin() or perf_aux_output_end(), the wakeup is
dropped leaving userspace hanging forever on the poll.
Normally the event is explicitly re-enabled by userspace after it
wakes up to read the aux data, but in this case it does not get woken
up so the event remains disabled.
This can be reproduced when using Arm SPE and 'stress' which forks once
before running the workload. By looking at the list of aux buffers read,
it's apparent that they stop after the fork:
perf record -e arm_spe// -vvv -- stress -c 1
With this patch applied they continue to be printed. This behaviour
doesn't happen when using systemwide or per-cpu mode.
Reported-by: Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211206113840.130802-2-james.clark@arm.com
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Time readers that cannot take locks (due to NMI etc..) currently make
use of perf_event::shadow_ctx_time, which, for that event gives:
time' = now + (time - timestamp)
or, alternatively arranged:
time' = time + (now - timestamp)
IOW, the progression of time since the last time the shadow_ctx_time
was updated.
There's problems with this:
A) the shadow_ctx_time is per-event, even though the ctx_time it
reflects is obviously per context. The direct concequence of this
is that the context needs to iterate all events all the time to
keep the shadow_ctx_time in sync.
B) even with the prior point, the context itself might not be active
meaning its time should not advance to begin with.
C) shadow_ctx_time isn't consistently updated when ctx_time is
There are 3 users of this stuff, that suffer differently from this:
- calc_timer_values()
- perf_output_read()
- perf_event_update_userpage() /* A */
- perf_event_read_local() /* A,B */
In particular, perf_output_read() doesn't suffer at all, because it's
sample driven and hence only relevant when the event is actually
running.
This same was supposed to be true for perf_event_update_userpage(),
after all self-monitoring implies the context is active *HOWEVER*, as
per commit f79256532682 ("perf/core: fix userpage->time_enabled of
inactive events") this goes wrong when combined with counter
overcommit, in that case those events that do not get scheduled when
the context becomes active (task events typically) miss out on the
EVENT_TIME update and ENABLED time is inflated (for a little while)
with the time the context was inactive. Once the event gets rotated
in, this gets corrected, leading to a non-monotonic timeflow.
perf_event_read_local() made things even worse, it can request time at
any point, suffering all the problems perf_event_update_userpage()
does and more. Because while perf_event_update_userpage() is limited
by the context being active, perf_event_read_local() users have no
such constraint.
Therefore, completely overhaul things and do away with
perf_event::shadow_ctx_time. Instead have regular context time updates
keep track of this offset directly and provide perf_event_time_now()
to complement perf_event_time().
perf_event_time_now() will, in adition to being context wide, also
take into account if the context is active. For inactive context, it
will not advance time.
This latter property means the cgroup perf_cgroup_info context needs
to grow addition state to track this.
Additionally, since all this is strictly per-cpu, we can use barrier()
to order context activity vs context time.
Fixes: 7d9285e82db5 ("perf/bpf: Extend the perf_event_read_local() interface, a.k.a. "bpf: perf event change needed for subsequent bpf helpers"")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Song Liu <song@kernel.org>
Tested-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/YcB06DasOBtU0b00@hirez.programming.kicks-ass.net
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Borislav Petkov:
"Cleanup of the perf/kvm interaction."
* tag 'perf_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Drop guest callback (un)register stubs
KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c
KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y
KVM: arm64: Convert to the generic perf callbacks
KVM: x86: Move Intel Processor Trace interrupt handler to vmx.c
KVM: Move x86's perf guest info callbacks to generic KVM
KVM: x86: More precisely identify NMI from guest when handling PMI
KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable
perf/core: Use static_call to optimize perf_guest_info_callbacks
perf: Force architectures to opt-in to guest callbacks
perf: Add wrappers for invoking guest callbacks
perf/core: Rework guest callbacks to prepare for static_call support
perf: Drop dead and useless guest "support" from arm, csky, nds32 and riscv
perf: Stop pretending that perf can handle multiple guest callbacks
KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest
KVM: x86: Register perf callbacks after calling vendor's hardware_setup()
perf: Protect perf_guest_cbs with RCU
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On arm64, user space counter access will be controlled differently
compared to x86. On x86, access in the strictest mode is enabled for all
tasks in an MM when any event is mmap'ed. For arm64, access is
explicitly requested for an event and only enabled when the event's
context is active. This avoids hooks into the arch context switch code
and gives better control of when access is enabled.
In order to configure user space access when the PMU is enabled, it is
necessary to know if any event (currently active or not) in the current
context has user space accessed enabled. Add a counter similar to other
counters in the context to avoid walking the event list every time.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211208201124.310740-3-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
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|
syzbot reported that the warning in perf_sigtrap() fires, saying that
the event's task does not match current:
| WARNING: CPU: 0 PID: 9090 at kernel/events/core.c:6446 perf_pending_event+0x40d/0x4b0 kernel/events/core.c:6513
| Modules linked in:
| CPU: 0 PID: 9090 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
| RIP: 0010:perf_sigtrap kernel/events/core.c:6446 [inline]
| RIP: 0010:perf_pending_event_disable kernel/events/core.c:6470 [inline]
| RIP: 0010:perf_pending_event+0x40d/0x4b0 kernel/events/core.c:6513
| ...
| Call Trace:
| <IRQ>
| irq_work_single+0x106/0x220 kernel/irq_work.c:211
| irq_work_run_list+0x6a/0x90 kernel/irq_work.c:242
| irq_work_run+0x4f/0xd0 kernel/irq_work.c:251
| __sysvec_irq_work+0x95/0x3d0 arch/x86/kernel/irq_work.c:22
| sysvec_irq_work+0x8e/0xc0 arch/x86/kernel/irq_work.c:17
| </IRQ>
| <TASK>
| asm_sysvec_irq_work+0x12/0x20 arch/x86/include/asm/idtentry.h:664
| RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
| RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194
| ...
| coredump_task_exit kernel/exit.c:371 [inline]
| do_exit+0x1865/0x25c0 kernel/exit.c:771
| do_group_exit+0xe7/0x290 kernel/exit.c:929
| get_signal+0x3b0/0x1ce0 kernel/signal.c:2820
| arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868
| handle_signal_work kernel/entry/common.c:148 [inline]
| exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
| exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207
| __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
| syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
| do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
| entry_SYSCALL_64_after_hwframe+0x44/0xae
On x86 this shouldn't happen, which has arch_irq_work_raise().
The test program sets up a perf event with sigtrap set to fire on the
'sched_wakeup' tracepoint, which fired in ttwu_do_wakeup().
This happened because the 'sched_wakeup' tracepoint also takes a task
argument passed on to perf_tp_event(), which is used to deliver the
event to that other task.
Since we cannot deliver synchronous signals to other tasks, skip an event if
perf_tp_event() is targeted at another task and perf_event_attr::sigtrap is
set, which will avoid ever entering perf_sigtrap() for such events.
Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events")
Reported-by: syzbot+663359e32ce6f1a305ad@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YYpoCOBmC/kJWfmI@elver.google.com
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Use static_call to optimize perf's guest callbacks on arm64 and x86,
which are now the only architectures that define the callbacks. Use
DEFINE_STATIC_CALL_RET0 as the default/NULL for all guest callbacks, as
the callback semantics are that a return value '0' means "not in guest".
static_call obviously avoids the overhead of CONFIG_RETPOLINE=y, but is
also advantageous versus other solutions, e.g. per-cpu callbacks, in that
a per-cpu memory load is not needed to detect the !guest case.
Based on code from Peter and Like.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-10-seanjc@google.com
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Introduce GUEST_PERF_EVENTS and require architectures to select it to
allow registering and using guest callbacks in perf. This will hopefully
make it more difficult for new architectures to add useless "support" for
guest callbacks, e.g. via copy+paste.
Stubbing out the helpers has the happy bonus of avoiding a load of
perf_guest_cbs when GUEST_PERF_EVENTS=n on arm64/x86.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-9-seanjc@google.com
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Drop the 'int' return value from the perf (un)register callbacks helpers
and stop pretending perf can support multiple callbacks. The 'int'
returns are not future proofing anything as none of the callers take
action on an error. It's also not obvious that there will ever be
co-tenant hypervisors, and if there are, that allowing multiple callbacks
to be registered is desirable or even correct.
Opportunistically rename callbacks=>cbs in the affected declarations to
match their definitions.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20211111020738.2512932-5-seanjc@google.com
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Protect perf_guest_cbs with RCU to fix multiple possible errors. Luckily,
all paths that read perf_guest_cbs already require RCU protection, e.g. to
protect the callback chains, so only the direct perf_guest_cbs touchpoints
need to be modified.
Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure
perf_guest_cbs isn't reloaded between a !NULL check and a dereference.
Fixed via the READ_ONCE() in rcu_dereference().
Bug #2 is that on weakly-ordered architectures, updates to the callbacks
themselves are not guaranteed to be visible before the pointer is made
visible to readers. Fixed by the smp_store_release() in
rcu_assign_pointer() when the new pointer is non-NULL.
Bug #3 is that, because the callbacks are global, it's possible for
readers to run in parallel with an unregisters, and thus a module
implementing the callbacks can be unloaded while readers are in flight,
resulting in a use-after-free. Fixed by a synchronize_rcu() call when
unregistering callbacks.
Bug #1 escaped notice because it's extremely unlikely a compiler will
reload perf_guest_cbs in this sequence. perf_guest_cbs does get reloaded
for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest()
guard all but guarantees the consumer will win the race, e.g. to nullify
perf_guest |