mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-01-04 04:04:19 +00:00
ebc008699f
1167 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Waiman Long
|
d566c78659 |
locking/rwsem: Clarify that RWSEM_READER_OWNED is just a hint
Clarify in the comments that the RWSEM_READER_OWNED bit in the owner field is just a hint, not an authoritative state of the rwsem. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240222150540.79981-4-longman@redhat.com |
||
|
Waiman Long
|
ca4bc2e07b |
locking/qspinlock: Fix 'wait_early' set but not used warning
When CONFIG_LOCK_EVENT_COUNTS is off, the wait_early variable will be set but not used. This is expected. Recent compilers will not generate wait_early code in this case. Add the __maybe_unused attribute to wait_early for suppressing this W=1 warning. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240222150540.79981-2-longman@redhat.com Closes: https://lore.kernel.org/oe-kbuild-all/202312260422.f4pK3f9m-lkp@intel.com/ |
||
|
Linus Torvalds
|
23a80d462c |
RCU pull request for v6.8
This pull request contains the following branches:
doc.2023.12.13a: Documentation and comment updates.
torture.2023.11.23a: RCU torture, locktorture updates that include
cleanups; nolibc init build support for mips, ppc and rv64;
testing of mid stall duration scenario and fixing fqs task
creation conditions.
fixes.2023.12.13a: Misc fixes, most notably restricting usage of
RCU CPU stall notifiers, to confine their usage primarily
to debug kernels.
rcu-tasks.2023.12.12b: RCU tasks minor fixes.
srcu.2023.12.13a: lockdep annotation fix for NMI-safe accesses,
callback advancing/acceleration cleanup and documentation
improvements.
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQSi2tPIQIc2VEtjarIAHS7/6Z0wpQUCZYUS0AAKCRAAHS7/6Z0w
pRXgAQD+k8oqjvKL6la61ppWm5Y7NLjdj/IbV+cOd42jKnM6PAEAyavNhX0n7zGx
o9cDlvIDxJfHnFrOTc5WLH9yEs3IiQQ=
=8rdu
-----END PGP SIGNATURE-----
Merge tag 'rcu.release.v6.8' of https://github.com/neeraju/linux
Pull RCU updates from Neeraj Upadhyay:
- Documentation and comment updates
- RCU torture, locktorture updates that include cleanups; nolibc init
build support for mips, ppc and rv64; testing of mid stall duration
scenario and fixing fqs task creation conditions
- Misc fixes, most notably restricting usage of RCU CPU stall
notifiers, to confine their usage primarily to debug kernels
- RCU tasks minor fixes
- lockdep annotation fix for NMI-safe accesses, callback
advancing/acceleration cleanup and documentation improvements
* tag 'rcu.release.v6.8' of https://github.com/neeraju/linux:
rcu: Force quiescent states only for ongoing grace period
doc: Clarify historical disclaimers in memory-barriers.txt
doc: Mention address and data dependencies in rcu_dereference.rst
doc: Clarify RCU Tasks reader/updater checklist
rculist.h: docs: Fix wrong function summary
Documentation: RCU: Remove repeated word in comments
srcu: Use try-lock lockdep annotation for NMI-safe access.
srcu: Explain why callbacks invocations can't run concurrently
srcu: No need to advance/accelerate if no callback enqueued
srcu: Remove superfluous callbacks advancing from srcu_gp_start()
rcu: Remove unused macros from rcupdate.h
rcu: Restrict access to RCU CPU stall notifiers
rcu-tasks: Mark RCU Tasks accesses to current->rcu_tasks_idle_cpu
rcutorture: Add fqs_holdoff check before fqs_task is created
rcutorture: Add mid-sized stall to TREE07
rcutorture: add nolibc init support for mips, ppc and rv64
locktorture: Increase Hamming distance between call_rcu_chain and rcu_call_chains
|
||
|
Linus Torvalds
|
78273df7f6 |
header cleanups for 6.8
The goal is to get sched.h down to a type only header, so the main thing happening in this patchset is splitting out various _types.h headers and dependency fixups, as well as moving some things out of sched.h to better locations. This is prep work for the memory allocation profiling patchset which adds new sched.h interdepencencies. Testing - it's been in -next, and fixes from pretty much all architectures have percolated in - nothing major. -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEKnAFLkS8Qha+jvQrE6szbY3KbnYFAmWfBwwACgkQE6szbY3K bnZPwBAAmuRojXaeWxi01IPIOehSGDe68vw44PR9glEMZvxdnZuPOdvE4/+245/L bRKU2WBCjBUokUbV9msIShwRkFTZAmEMPNfPAAsFMA+VXeDYHKB+ZRdwTggNAQ+I SG6fZgh5m0HsewCDxU8oqVHkjVq4fXn0cy+aL6xLEd9gu67GoBzX2pDieS2Kvy6j jnyoKTxFwb+LTQgph0P4EIpq5I2umAsdLwdSR8EJ+8e9NiNvMo1pI00Lx/ntAnFZ JftWUJcMy3TQ5u1GkyfQN9y/yThX1bZK5GvmHS9SJ2Dkacaus5d+xaKCHtRuFS1I 7C6b8PsNgRczUMumBXus44HdlNfNs1yU3lvVxFvBIPE1qC9pYRHrkWIXXIocXLLC oxTEJ6B2G3BQZVQgLIA4fOaxMVhmvKffi/aEZLi9vN9VVosd1a6XNKI6KbyRnXFp GSs9qDqszhn5I3GYNlDNQTc/8UsRlhPFgS6nS0By6QnvxtGi9QkU2tBRBsXvqwCy cLoCYIhc2tvugHvld70dz26umiJ4rnmxGlobStNoigDvIKAIUt1UmIdr1so8P8eH xehnL9ZcOX6xnANDL0AqMFFHV6I58CJynhFdUoXfVQf/DWLGX48mpi9LVNsYBzsI CAwVOAQ0UjGrpdWmJ9ueY/ABYqg9vRjzaDEXQ+MhAYO55CLaVsg= =3tyT -----END PGP SIGNATURE----- Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs Pull header cleanups from Kent Overstreet: "The goal is to get sched.h down to a type only header, so the main thing happening in this patchset is splitting out various _types.h headers and dependency fixups, as well as moving some things out of sched.h to better locations. This is prep work for the memory allocation profiling patchset which adds new sched.h interdepencencies" * tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits) Kill sched.h dependency on rcupdate.h kill unnecessary thread_info.h include Kill unnecessary kernel.h include preempt.h: Kill dependency on list.h rseq: Split out rseq.h from sched.h LoongArch: signal.c: add header file to fix build error restart_block: Trim includes lockdep: move held_lock to lockdep_types.h sem: Split out sem_types.h uidgid: Split out uidgid_types.h seccomp: Split out seccomp_types.h refcount: Split out refcount_types.h uapi/linux/resource.h: fix include x86/signal: kill dependency on time.h syscall_user_dispatch.h: split out *_types.h mm_types_task.h: Trim dependencies Split out irqflags_types.h ipc: Kill bogus dependency on spinlock.h shm: Slim down dependencies workqueue: Split out workqueue_types.h ... |
||
|
Ingo Molnar
|
67a1723344 |
Linux 6.7-rc8
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmWR1E0eHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGYb8H/j5KAXUH3rvY3I7z pLZkdQiFX/ix2p25VYCNEes/h9gRLNTX0ndr+qd/LSjunaF17x+j0odHpjaK7dV0 YwSiP+ffNY8zDjHJP3mAbNfyov37kZjrtjciEs9/Ldk0w9Swp91iJZC6mRsJ6LbV kneZ/5nQIfZn0KFgqNCrrfCvUf3TcRskNFDvguDLCXf+lg5nJmhJnbGRExDqe5vs VIbfI9nnIjZd0Pt5rsXSQfwk0RaK/85unz6Dfshny9vAHnfTC5tX1B0sAqga+Zji nQtHQ/UT/gLSY0b/PoRXjA4wenv5UdTwKs7XaKaGKpyaDlD35CxiWXi8xhdgw+qG X4LFgDY= =N/Fv -----END PGP SIGNATURE----- Merge tag 'v6.7-rc8' into locking/core, to pick up dependent changes Pick up these commits from Linus's tree: |
||
|
David Laight
|
b106bcf0f9 |
locking/osq_lock: Clarify osq_wait_next()
Directly return NULL or 'next' instead of breaking out of the loop. Signed-off-by: David Laight <david.laight@aculab.com> [ Split original patch into two independent parts - Linus ] Link: https://lore.kernel.org/lkml/7c8828aec72e42eeb841ca0ee3397e9a@AcuMS.aculab.com/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
David Laight
|
563adbfc35 |
locking/osq_lock: Clarify osq_wait_next() calling convention
osq_wait_next() is passed 'prev' from osq_lock() and NULL from osq_unlock() but only needs the 'cpu' value to write to lock->tail. Just pass prev->cpu or OSQ_UNLOCKED_VAL instead. Should have no effect on the generated code since gcc manages to assume that 'prev != NULL' due to an earlier dereference. Signed-off-by: David Laight <david.laight@aculab.com> [ Changed 'old' to 'old_cpu' by request from Waiman Long - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
David Laight
|
7c22309821 |
locking/osq_lock: Move the definition of optimistic_spin_node into osq_lock.c
struct optimistic_spin_node is private to the implementation. Move it into the C file to ensure nothing is accessing it. Signed-off-by: David Laight <david.laight@aculab.com> Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Kent Overstreet
|
f551103cb9 |
sched.h: move pid helpers to pid.h
This is needed for killing the sched.h dependency on rcupdate.h, and pid.h is a better place for this code anyways. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> |
||
|
Jann Horn
|
a51749ab34 |
locking/mutex: Document that mutex_unlock() is non-atomic
I have seen several cases of attempts to use mutex_unlock() to release an object such that the object can then be freed by another task. This is not safe because mutex_unlock(), in the MUTEX_FLAG_WAITERS && !MUTEX_FLAG_HANDOFF case, accesses the mutex structure after having marked it as unlocked; so mutex_unlock() requires its caller to ensure that the mutex stays alive until mutex_unlock() returns. If MUTEX_FLAG_WAITERS is set and there are real waiters, those waiters have to keep the mutex alive, but we could have a spurious MUTEX_FLAG_WAITERS left if an interruptible/killable waiter bailed between the points where __mutex_unlock_slowpath() did the cmpxchg reading the flags and where it acquired the wait_lock. ( With spinlocks, that kind of code pattern is allowed and, from what I remember, used in several places in the kernel. ) Document this, such a semantic difference between mutexes and spinlocks is fairly unintuitive. [ mingo: Made the changelog a bit more assertive, refined the comments. ] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231130204817.2031407-1-jannh@google.com |
||
|
Peter Zijlstra
|
bca4104b00 |
lockdep: Fix block chain corruption
Kent reported an occasional KASAN splat in lockdep. Mark then noted:
> I suspect the dodgy access is to chain_block_buckets[-1], which hits the last 4
> bytes of the redzone and gets (incorrectly/misleadingly) attributed to
> nr_large_chain_blocks.
That would mean @size == 0, at which point size_to_bucket() returns -1
and the above happens.
alloc_chain_hlocks() has 'size - req', for the first with the
precondition 'size >= rq', which allows the 0.
This code is trying to split a block, del_chain_block() takes what we
need, and add_chain_block() puts back the remainder, except in the
above case the remainder is 0 sized and things go sideways.
Fixes:
|
||
|
Paul E. McKenney
|
69dcbbd804 |
locktorture: Increase Hamming distance between call_rcu_chain and rcu_call_chains
One letter difference is really not enough, so this commit changes call_rcu_chain to call_rcu_chain_list. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com> |
||
|
Linus Torvalds
|
2656821f1f |
RCU pull request for v6.7
This pull request contains the following branches:
rcu/torture: RCU torture, locktorture and generic torture infrastructure
updates that include various fixes, cleanups and consolidations.
Among the user visible things, ftrace dumps can now be found into
their own file, and module parameters get better documented and
reported on dumps.
rcu/fixes: Generic and misc fixes all over the place. Some highlights:
* Hotplug handling has seen some light cleanups and comments.
* An RCU barrier can now be triggered through sysfs to serialize
memory stress testing and avoid OOM.
* Object information is now dumped in case of invalid callback
invocation.
* Also various SRCU issues, too hard to trigger to deserve urgent
pull requests, have been fixed.
rcu/docs: RCU documentation updates
rcu/refscale: RCU reference scalability test minor fixes and doc
improvements.
rcu/tasks: RCU tasks minor fixes
rcu/stall: Stall detection updates. Introduce RCU CPU Stall notifiers
that allows a subsystem to provide informations to help debugging.
Also cure some false positive stalls.
-----BEGIN PGP SIGNATURE-----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=cVD7
-----END PGP SIGNATURE-----
Merge tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks
Pull RCU updates from Frederic Weisbecker:
- RCU torture, locktorture and generic torture infrastructure updates
that include various fixes, cleanups and consolidations.
Among the user visible things, ftrace dumps can now be found into
their own file, and module parameters get better documented and
reported on dumps.
- Generic and misc fixes all over the place. Some highlights:
* Hotplug handling has seen some light cleanups and comments
* An RCU barrier can now be triggered through sysfs to serialize
memory stress testing and avoid OOM
* Object information is now dumped in case of invalid callback
invocation
* Also various SRCU issues, too hard to trigger to deserve urgent
pull requests, have been fixed
- RCU documentation updates
- RCU reference scalability test minor fixes and doc improvements.
- RCU tasks minor fixes
- Stall detection updates. Introduce RCU CPU Stall notifiers that
allows a subsystem to provide informations to help debugging. Also
cure some false positive stalls.
* tag 'rcu-next-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks: (56 commits)
srcu: Only accelerate on enqueue time
locktorture: Check the correct variable for allocation failure
srcu: Fix callbacks acceleration mishandling
rcu: Comment why callbacks migration can't wait for CPUHP_RCUTREE_PREP
rcu: Standardize explicit CPU-hotplug calls
rcu: Conditionally build CPU-hotplug teardown callbacks
rcu: Remove references to rcu_migrate_callbacks() from diagrams
rcu: Assume rcu_report_dead() is always called locally
rcu: Assume IRQS disabled from rcu_report_dead()
rcu: Use rcu_segcblist_segempty() instead of open coding it
rcu: kmemleak: Ignore kmemleak false positives when RCU-freeing objects
srcu: Fix srcu_struct node grpmask overflow on 64-bit systems
torture: Convert parse-console.sh to mktemp
rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle()
rcutorture: Replace schedule_timeout*() 1-jiffy waits with HZ/20
torture: Add kvm.sh --debug-info argument
locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers
doc: Catch-up update for locktorture module parameters
locktorture: Add call_rcu_chains module parameter
locktorture: Add new module parameters to lock_torture_print_module_parms()
...
|
||
|
Linus Torvalds
|
3cf3fabccb |
Locking changes in this cycle are:
- Futex improvements:
- Add the 'futex2' syscall ABI, which is an attempt to get away from the
multiplex syscall and adds a little room for extentions, while lifting
some limitations.
- Fix futex PI recursive rt_mutex waiter state bug
- Fix inter-process shared futexes on no-MMU systems
- Use folios instead of pages
- Micro-optimizations of locking primitives:
- Improve arch_spin_value_unlocked() on asm-generic ticket spinlock
architectures, to improve lockref code generation.
- Improve the x86-32 lockref_get_not_zero() main loop by adding
build-time CMPXCHG8B support detection for the relevant lockref code,
and by better interfacing the CMPXCHG8B assembly code with the compiler.
- Introduce arch_sync_try_cmpxchg() on x86 to improve sync_try_cmpxchg()
code generation. Convert some sync_cmpxchg() users to sync_try_cmpxchg().
- Micro-optimize rcuref_put_slowpath()
- Locking debuggability improvements:
- Improve CONFIG_DEBUG_RT_MUTEXES=y to have a fast-path as well
- Enforce atomicity of sched_submit_work(), which is de-facto atomic but
was un-enforced previously.
- Extend <linux/cleanup.h>'s no_free_ptr() with __must_check semantics
- Fix ww_mutex self-tests
- Clean up const-propagation in <linux/seqlock.h> and simplify
the API-instantiation macros a bit.
- RT locking improvements:
- Provide the rt_mutex_*_schedule() primitives/helpers and use them
in the rtmutex code to avoid recursion vs. rtlock on the PI state.
- Add nested blocking lockdep asserts to rt_mutex_lock(), rtlock_lock()
and rwbase_read_lock().
- Plus misc fixes & cleanups
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=36Ff
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Info Molnar:
"Futex improvements:
- Add the 'futex2' syscall ABI, which is an attempt to get away from
the multiplex syscall and adds a little room for extentions, while
lifting some limitations.
- Fix futex PI recursive rt_mutex waiter state bug
- Fix inter-process shared futexes on no-MMU systems
- Use folios instead of pages
Micro-optimizations of locking primitives:
- Improve arch_spin_value_unlocked() on asm-generic ticket spinlock
architectures, to improve lockref code generation
- Improve the x86-32 lockref_get_not_zero() main loop by adding
build-time CMPXCHG8B support detection for the relevant lockref
code, and by better interfacing the CMPXCHG8B assembly code with
the compiler
- Introduce arch_sync_try_cmpxchg() on x86 to improve
sync_try_cmpxchg() code generation. Convert some sync_cmpxchg()
users to sync_try_cmpxchg().
- Micro-optimize rcuref_put_slowpath()
Locking debuggability improvements:
- Improve CONFIG_DEBUG_RT_MUTEXES=y to have a fast-path as well
- Enforce atomicity of sched_submit_work(), which is de-facto atomic
but was un-enforced previously.
- Extend <linux/cleanup.h>'s no_free_ptr() with __must_check
semantics
- Fix ww_mutex self-tests
- Clean up const-propagation in <linux/seqlock.h> and simplify the
API-instantiation macros a bit
RT locking improvements:
- Provide the rt_mutex_*_schedule() primitives/helpers and use them
in the rtmutex code to avoid recursion vs. rtlock on the PI state.
- Add nested blocking lockdep asserts to rt_mutex_lock(),
rtlock_lock() and rwbase_read_lock()
.. plus misc fixes & cleanups"
* tag 'locking-core-2023-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
futex: Don't include process MM in futex key on no-MMU
locking/seqlock: Fix grammar in comment
alpha: Fix up new futex syscall numbers
locking/seqlock: Propagate 'const' pointers within read-only methods, remove forced type casts
locking/lockdep: Fix string sizing bug that triggers a format-truncation compiler-warning
locking/seqlock: Change __seqprop() to return the function pointer
locking/seqlock: Simplify SEQCOUNT_LOCKNAME()
locking/atomics: Use atomic_try_cmpxchg_release() to micro-optimize rcuref_put_slowpath()
locking/atomic, xen: Use sync_try_cmpxchg() instead of sync_cmpxchg()
locking/atomic/x86: Introduce arch_sync_try_cmpxchg()
locking/atomic: Add generic support for sync_try_cmpxchg() and its fallback
locking/seqlock: Fix typo in comment
futex/requeue: Remove unnecessary ‘NULL’ initialization from futex_proxy_trylock_atomic()
locking/local, arch: Rewrite local_add_unless() as a static inline function
locking/debug: Fix debugfs API return value checks to use IS_ERR()
locking/ww_mutex/test: Make sure we bail out instead of livelock
locking/ww_mutex/test: Fix potential workqueue corruption
locking/ww_mutex/test: Use prng instead of rng to avoid hangs at bootup
futex: Add sys_futex_requeue()
futex: Add flags2 argument to futex_requeue()
...
|
||
|
Brian Foster
|
957e48087d |
locking: export contention tracepoints for bcachefs six locks
The bcachefs implementation of six locks is intended to land in generic locking code in the long term, but has been pulled into the bcachefs subsystem for internal use for the time being. This code lift breaks the bcachefs module build as six locks depend a couple of the generic locking tracepoints. Export these tracepoint symbols for bcachefs. Signed-off-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> |
||
|
Lucy Mielke
|
ac8b60be07 |
locking/lockdep: Fix string sizing bug that triggers a format-truncation compiler-warning
On an allyesconfig, with "treat warnings as errors" unset, GCC emits these warnings: kernel/locking/lockdep_proc.c:438:32: Warning: Format specifier '%lld' may be truncated when writing 1 to 17 bytes into a region of size 15 [-Wformat-truncation=] kernel/locking/lockdep_proc.c:438:31: Note: Format directive argument is in the range [-9223372036854775, 9223372036854775] kernel/locking/lockdep_proc.c:438:9: Note: 'snprintf' has output between 5 and 22 bytes into a target of size 15 In seq_time(), the longest s64 is "-9223372036854775808"-ish, which converted to the fixed-point float format is "-9223372036854775.80": 21 bytes, plus termination is another byte: 22. Therefore, a larger buffer size of 22 is needed here - not 15. The code was safe due to the snprintf(). Fix it. Signed-off-by: Lucy Mielke <lucymielke@icloud.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/ZSfOEHRkZAWaQr3U@fedora.fritz.box |
||
|
Dan Carpenter
|
cefe8ce559 |
locktorture: Check the correct variable for allocation failure
There is a typo so this checks the wrong variable. "chains" plural vs
"chain" singular. We already know that "chains" is non-zero.
Fixes:
|
||
|
Atul Kumar Pant
|
8788c6c2fe |
locking/debug: Fix debugfs API return value checks to use IS_ERR()
Update the checking of return values from debugfs_create_file() and debugfs_create_dir() to use IS_ERR(). Signed-off-by: Atul Kumar Pant <atulpant.linux@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20230807121834.7438-1-atulpant.linux@gmail.com |
||
|
Paul E. McKenney
|
2273799c29 |
locktorture: Rename readers_bind/writers_bind to bind_readers/bind_writers
This commit renames the readers_bind and writers_bind module parameters to bind_readers and bind_writers, respectively. This provides added clarity via the imperative mode and better organizes the documentation. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
7f993623e9 |
locktorture: Add call_rcu_chains module parameter
When running locktorture on large systems, there will normally be enough RCU activity to ensure that there is a grace period in flight at all times. However, on smaller systems, RCU might well be idle the majority of the time. This situation can be inconvenient in cases where the RCU CPU stall warning is part of the debugging process. This commit therefore adds an call_rcu_chains module parameter to locktorture, allowing the user to specify the desired number of self-propagating call_rcu() chains. For good measure, immediately before invoking call_rcu(), the self-propagating RCU callback invokes start_poll_synchronize_rcu() to force the immediate start of a grace period, with the call_rcu() forcing another to start shortly thereafter. Booting with locktorture.call_rcu_chains=2 increases the probability of a stuck locking primitive resulting in an RCU CPU stall warning from about 25% to nearly 100%. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
00c24c9cfa |
locktorture: Add new module parameters to lock_torture_print_module_parms()
This commit adds new module parameters to lock_torture_print_module_parms, and alphabetizes things while in the area. This change makes locktorture test results more useful and self-contained. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
e3bdaefbcc |
locktorture: Add acq_writer_lim to complain about long acquistion times
This commit adds a locktorture.acq_writer_lim module parameter that specifies the maximum number of jiffies that is expected to be consumed by write-side lock acquisition. If this limit is exceeded, a WARN_ONCE() causes a splat. Note that this limit applies to the main lock acquisition only, not to any nested acquisitions. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
84cee9e72e |
locktorture: Consolidate "if" statements in lock_torture_writer()
There is a pair of adjacent "if" statements with identical conditions in the lock_torture_writer() function. This commit therefore combines them. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
31742a56c6 |
locktorture: Alphabetize torture_param() entries
There are getting to be too many module parameters for a random list to be comfortable, so this commit alphabetizes the list. Strictly code motion. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
Paul E. McKenney
|
73e3412424 |
locktorture: Add readers_bind and writers_bind module parameters
This commit adds readers_bind and writers_bind module parameters to locktorture in order to skew tests across socket boundaries. This skewing is intended to provide additional variable-latency stress on the primitive under test. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> |
||
|
John Stultz
|
cfa92b6d52 |
locking/ww_mutex/test: Make sure we bail out instead of livelock
I've seen what appears to be livelocks in the stress_inorder_work() function, and looking at the code it is clear we can have a case where we continually retry acquiring the locks and never check to see if we have passed the specified timeout. This patch reworks that function so we always check the timeout before iterating through the loop again. I believe others may have hit this previously here: https://lore.kernel.org/lkml/895ef450-4fb3-5d29-a6ad-790657106a5a@intel.com/ Reported-by: Li Zhijian <zhijianx.li@intel.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-4-jstultz@google.com |
||
|
John Stultz
|
bccdd80890 |
locking/ww_mutex/test: Fix potential workqueue corruption
In some cases running with the test-ww_mutex code, I was seeing odd behavior where sometimes it seemed flush_workqueue was returning before all the work threads were finished. Often this would cause strange crashes as the mutexes would be freed while they were being used. Looking at the code, there is a lifetime problem as the controlling thread that spawns the work allocates the "struct stress" structures that are passed to the workqueue threads. Then when the workqueue threads are finished, they free the stress struct that was passed to them. Unfortunately the workqueue work_struct node is in the stress struct. Which means the work_struct is freed before the work thread returns and while flush_workqueue is waiting. It seems like a better idea to have the controlling thread both allocate and free the stress structures, so that we can be sure we don't corrupt the workqueue by freeing the structure prematurely. So this patch reworks the test to do so, and with this change I no longer see the early flush_workqueue returns. Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-3-jstultz@google.com |
||
|
John Stultz
|
4812c54dc0 |
locking/ww_mutex/test: Use prng instead of rng to avoid hangs at bootup
Booting w/ qemu without kvm, and with 64 cpus, I noticed we'd sometimes hung task watchdog splats in get_random_u32_below() when using the test-ww_mutex stress test. While entropy exhaustion is no longer an issue, the RNG may be slower early in boot. The test-ww_mutex code will spawn off 128 threads (2x cpus) and each thread will call get_random_u32_below() a number of times to generate a random order of the 16 locks. This intense use takes time and without kvm, qemu can be slow enough that we trip the hung task watchdogs. For this test, we don't need true randomness, just mixed up orders for testing ww_mutex lock acquisitions, so it changes the logic to use the prng instead, which takes less time and avoids the watchdgos. Feedback would be appreciated! Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230922043616.19282-2-jstultz@google.com |
||
|
Thomas Gleixner
|
45f67f30a2 |
locking/rtmutex: Add a lockdep assert to catch potential nested blocking
There used to be a BUG_ON(current->pi_blocked_on) in the lock acquisition functions, but that vanished in one of the rtmutex overhauls. Bring it back in form of a lockdep assert to catch code paths which take rtmutex based locks with current::pi_blocked_on != NULL. Reported-by: Crystal Wood <swood@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: "Peter Zijlstra (Intel)" <peterz@infradead.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-7-bigeasy@linutronix.de |
||
|
Sebastian Andrzej Siewior
|
d14f9e930b |
locking/rtmutex: Use rt_mutex specific scheduler helpers
Have rt_mutex use the rt_mutex specific scheduler helpers to avoid recursion vs rtlock on the PI state. [[ peterz: adapted to new names ]] Reported-by: Crystal Wood <swood@redhat.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-6-bigeasy@linutronix.de |
||
|
Sebastian Andrzej Siewior
|
af9f006393 |
locking/rtmutex: Avoid unconditional slowpath for DEBUG_RT_MUTEXES
With DEBUG_RT_MUTEXES enabled the fast-path rt_mutex_cmpxchg_acquire() always fails and all lock operations take the slow path. Provide a new helper inline rt_mutex_try_acquire() which maps to rt_mutex_cmpxchg_acquire() in the non-debug case. For the debug case it invokes rt_mutex_slowtrylock() which can acquire a non-contended rtmutex under full debug coverage. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230908162254.999499-3-bigeasy@linutronix.de |
||
|
Linus Torvalds
|
d68b4b6f30 |
- An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options").
- kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
couple of macros to args.h").
- gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
commands").
- vsprintf inclusion rationalization from Andy Shevchenko
("lib/vsprintf: Rework header inclusions").
- Switch the handling of kdump from a udev scheme to in-kernel handling,
by Eric DeVolder ("crash: Kernel handling of CPU and memory hot
un/plug").
- Many singleton patches to various parts of the tree
-----BEGIN PGP SIGNATURE-----
iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZO2GpAAKCRDdBJ7gKXxA
juW3AQD1moHzlSN6x9I3tjm5TWWNYFoFL8af7wXDJspp/DWH/AD/TO0XlWWhhbYy
QHy7lL0Syha38kKLMXTM+bN6YQHi9AU=
=WJQa
-----END PGP SIGNATURE-----
Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options")
- kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
couple of macros to args.h")
- gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
commands")
- vsprintf inclusion rationalization from Andy Shevchenko
("lib/vsprintf: Rework header inclusions")
- Switch the handling of kdump from a udev scheme to in-kernel
handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
hot un/plug")
- Many singleton patches to various parts of the tree
* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
document while_each_thread(), change first_tid() to use for_each_thread()
drivers/char/mem.c: shrink character device's devlist[] array
x86/crash: optimize CPU changes
crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
crash: hotplug support for kexec_load()
x86/crash: add x86 crash hotplug support
crash: memory and CPU hotplug sysfs attributes
kexec: exclude elfcorehdr from the segment digest
crash: add generic infrastructure for crash hotplug support
crash: move a few code bits to setup support of crash hotplug
kstrtox: consistently use _tolower()
kill do_each_thread()
nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
scripts/bloat-o-meter: count weak symbol sizes
treewide: drop CONFIG_EMBEDDED
lockdep: fix static memory detection even more
lib/vsprintf: declare no_hash_pointers in sprintf.h
lib/vsprintf: split out sprintf() and friends
kernel/fork: stop playing lockless games for exe_file replacement
adfs: delete unused "union adfs_dirtail" definition
...
|
||
|
Linus Torvalds
|
97efd28334 |
Misc x86 cleanups.
The following commit deserves special mention:
|
||
|
Linus Torvalds
|
68cadad11f |
RCU pull request for v6.6
doc.2023.07.14b: Documentation updates. fixes.2023.08.16a: Miscellaneous fixes, perhaps most notably simplifying SRCU_NOTIFIER_INIT() as suggested. rcu-tasks.2023.07.24a: RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy while still treating synchronous grace periods as urgent. Also fixes one bug that restores the ability to apply debug-objects to RCU Tasks and another that fixes a race condition that could result in false-positive failures of the boot-time self-test code. rcuscale.2023.07.14b: RCU-scalability performance-test updates, most notably adding the ability to measure the RCU-Tasks's grace-period kthread's CPU consumption. This proved quite useful for the rcu-tasks.2023.07.24a work. refscale.2023.07.14b: Reference-acquisition/release performance-test updates, including a fix for an uninitialized wait_queue_head_t. torture.2023.08.14a: Miscellaneous torture-test updates. torturescripts.2023.07.20a: Torture-test scripting updates, including removal of the non-longer-functional formal-verification scripts, test builds of individual RCU Tasks flavors, better diagnostics for loss of connectivity for distributed rcutorture tests, disabling of reboot loops in qemu/KVM-based rcutorture testing, and passing of init parameters to rcutorture's init program. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmTjkssTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jITND/9zEqYNbeFrcBs/YaHdoAjsNgOt1IYN csfF/KArVgdvmrwlV/nEaQMLaJcw9X7DVU5+7E2JbbDaB/2FSacseNyKk6mfgSVK /0rnTOXpqI9/T1HiJObWZvDQFuKL12bfteXWGJg1sMt2JUGZ4nAWhdZ3xRjp2XkO 89qB5r0fF8gyGwvQ3M29ss8T9Oy0uUNJmDY/QyVxHM6dhkpSAezFffKzD7C4zkSV WucRTpYJ7bs6otBGtVmwz3x60UAuLwcVfQyB+CTbnGLsps9yAYU+1DDVdm7olcr3 ARXMeboeodMvy9jWXhtbWRVAAob4lVUDXQN27kb4sBgroRQBfQXMuByRAU6s0VtX frOl6rlbORuAetsC8wFL0IFVn4yTpvXKbYw7h1MXTs7gVVbl33O9FieGvWu0r79/ VR4Xw+JbmYWtyvFV8Zaq4iIEcOe+PeNH6u0bPx+htsHYd1+DUG2UY0MVmJQ3a4sb ygejA6mguCk7KBzWab8wdDpgAfhNwg0T9a+LQYcaskuD5SSWjYqqg6i1ulqqqyiE bOfRKDX4mWmAobWKHLssqUrjiLbxfygIaHjCrt7rWJKPIs1bK/WfWa4JbrE0NRwK 9IDd1lWc9C+zoUpjyZWSG3ahK5lWo2u4sPNoRtMQjowjobIz1cBhaEwmFe72bG7C FCKb7Da2oUaLOw== =EujZ -----END PGP SIGNATURE----- Merge tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes, perhaps most notably simplifying SRCU_NOTIFIER_INIT() as suggested - RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy while still treating synchronous grace periods as urgent. Also fixes one bug that restores the ability to apply debug-objects to RCU Tasks and another that fixes a race condition that could result in false-positive failures of the boot-time self-test code - RCU-scalability performance-test updates, most notably adding the ability to measure the RCU-Tasks's grace-period kthread's CPU consumption. This proved quite useful for the RCU Tasks work - Reference-acquisition/release performance-test updates, including a fix for an uninitialized wait_queue_head_t - Miscellaneous torture-test updates - Torture-test scripting updates, including removal of the non-longer-functional formal-verification scripts, test builds of individual RCU Tasks flavors, better diagnostics for loss of connectivity for distributed rcutorture tests, disabling of reboot loops in qemu/KVM-based rcutorture testing, and passing of init parameters to rcutorture's init program * tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (64 commits) rcu: Use WRITE_ONCE() for assignments to ->next for rculist_nulls rcu: Make the rcu_nocb_poll boot parameter usable via boot config rcu: Mark __rcu_irq_enter_check_tick() ->rcu_urgent_qs load srcu,notifier: Remove #ifdefs in favor of SRCU Tiny srcu_usage rcutorture: Stop right-shifting torture_random() return values torture: Stop right-shifting torture_random() return values torture: Move stutter_wait() timeouts to hrtimers torture: Move torture_shuffle() timeouts to hrtimers torture: Move torture_onoff() timeouts to hrtimers torture: Make torture_hrtimeout_*() use TASK_IDLE torture: Add lock_torture writer_fifo module parameter torture: Add a kthread-creation callback to _torture_create_kthread() rcu-tasks: Fix boot-time RCU tasks debug-only deadlock rcu-tasks: Permit use of debug-objects with RCU Tasks flavors checkpatch: Complain about unexpected uses of RCU Tasks Trace torture: Cause mkinitrd.sh to indicate failure on compile errors torture: Make init program dump command-line arguments torture: Switch qemu from -nographic to -display none torture: Add init-program support for loongarch torture: Avoid torture-test reboot loops ... |
||
|
Helge Deller
|
0a6b58c5cd |
lockdep: fix static memory detection even more
On the parisc architecture, lockdep reports for all static objects which are in the __initdata section (e.g. "setup_done" in devtmpfs, "kthreadd_done" in init/main.c) this warning: INFO: trying to register non-static key. The warning itself is wrong, because those objects are in the __initdata section, but the section itself is on parisc outside of range from _stext to _end, which is why the static_obj() functions returns a wrong answer. While fixing this issue, I noticed that the whole existing check can be simplified a lot. Instead of checking against the _stext and _end symbols (which include code areas too) just check for the .data and .bss segments (since we check a data object). This can be done with the existing is_kernel_core_data() macro. In addition objects in the __initdata section can be checked with init_section_contains(), and is_kernel_rodata() allows keys to be in the _ro_after_init section. This partly reverts and simplifies commit |
||
|
Dietmar Eggemann
|
5d248bb39f |
torture: Add lock_torture writer_fifo module parameter
This commit adds a module parameter that causes the locktorture writer to run at real-time priority. To use it: insmod /lib/modules/torture.ko random_shuffle=1 insmod /lib/modules/locktorture.ko torture_type=mutex_lock rt_boost=1 rt_boost_factor=50 nested_locks=3 writer_fifo=1 ^^^^^^^^^^^^^ A predecessor to this patch has been helpful to uncover issues with the proxy-execution series. [ paulmck: Remove locktorture-specific code from kernel/torture.c. ] Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: kernel-team@android.com Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> [jstultz: Include header change to build, reword commit message] Signed-off-by: John Stultz <jstultz@google.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Arnd Bergmann
|
8874a414f8 |
x86/qspinlock-paravirt: Fix missing-prototype warning
__pv_queued_spin_unlock_slowpath() is defined in a header file as
a global function, and designed to be called from inline asm, but
there is no prototype visible in the definition:
kernel/locking/qspinlock_paravirt.h:493:1: error: no previous \
prototype for '__pv_queued_spin_unlock_slowpath' [-Werror=missing-prototypes]
Add this to the x86 header that contains the inline asm calling it,
and ensure this gets included before the definition, rather than
after it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230803082619.1369127-8-arnd@kernel.org
|
||
|
Peter Zijlstra
|
f7853c3424 |
locking/rtmutex: Fix task->pi_waiters integrity
Henry reported that rt_mutex_adjust_prio_check() has an ordering
problem and puts the lie to the comment in [7]. Sharing the sort key
between lock->waiters and owner->pi_waiters *does* create problems,
since unlike what the comment claims, holding [L] is insufficient.
Notably, consider:
A
/ \
M1 M2
| |
B C
That is, task A owns both M1 and M2, B and C block on them. In this
case a concurrent chain walk (B & C) will modify their resp. sort keys
in [7] while holding M1->wait_lock and M2->wait_lock. So holding [L]
is meaningless, they're different Ls.
This then gives rise to a race condition between [7] and [11], where
the requeue of pi_waiters will observe an inconsistent tree order.
B C
(holds M1->wait_lock, (holds M2->wait_lock,
holds B->pi_lock) holds A->pi_lock)
[7]
waiter_update_prio();
...
[8]
raw_spin_unlock(B->pi_lock);
...
[10]
raw_spin_lock(A->pi_lock);
[11]
rt_mutex_enqueue_pi();
// observes inconsistent A->pi_waiters
// tree order
Fixing this means either extending the range of the owner lock from
[10-13] to [6-13], with the immediate problem that this means [6-8]
hold both blocked and owner locks, or duplicating the sort key.
Since the locking in chain walk is horrible enough without having to
consider pi_lock nesting rules, duplicate the sort key instead.
By giving each tree their own sort key, the above race becomes
harmless, if C sees B at the old location, then B will correct things
(if they need correcting) when it walks up the chain and reaches A.
Fixes:
|
||
|
Linus Torvalds
|
77b1a7f7a0 |
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in
top-level directories. - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs. - Zhen Lei has enhanced kexec's ability to support two crash regions. - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries. - And the usual bunch of singleton patches in various places. -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZJelTAAKCRDdBJ7gKXxA juDkAP0VXWynzkXoojdS/8e/hhi+htedmQ3v2dLZD+vBrctLhAEA7rcH58zAVoWa 2ejqO6wDrRGUC7JQcO9VEjT0nv73UwU= =F293 -----END PGP SIGNATURE----- Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-mm updates from Andrew Morton: - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level directories - Douglas Anderson has added a new "buddy" mode to the hardlockup detector. It permits the detector to work on architectures which cannot provide the required interrupts, by having CPUs periodically perform checks on other CPUs - Zhen Lei has enhanced kexec's ability to support two crash regions - Petr Mladek has done a lot of cleanup on the hard lockup detector's Kconfig entries - And the usual bunch of singleton patches in various places * tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits) kernel/time/posix-stubs.c: remove duplicated include ocfs2: remove redundant assignment to variable bit_off watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h devres: show which resource was invalid in __devm_ioremap_resource() watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64 watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h watchdog/hardlockup: make the config checks more straightforward watchdog/hardlockup: sort hardlockup detector related config values a logical way watchdog/hardlockup: move SMP barriers from common code to buddy code watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY watchdog/buddy: don't copy the cpumask in watchdog_next_cpu() watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog() watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy() watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick() watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe() watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails ... |
||
|
Linus Torvalds
|
bc6cb4d5bc |
Locking changes for v6.5:
- Introduce cmpxchg128() -- aka. the demise of cmpxchg_double().
The cmpxchg128() family of functions is basically & functionally
the same as cmpxchg_double(), but with a saner interface: instead
of a 6-parameter horror that forced u128 - u64/u64-halves layout
details on the interface and exposed users to complexity,
fragility & bugs, use a natural 3-parameter interface with u128 types.
- Restructure the generated atomic headers, and add
kerneldoc comments for all of the generic atomic{,64,_long}_t
operations. Generated definitions are much cleaner now,
and come with documentation.
- Implement lock_set_cmp_fn() on lockdep, for defining an ordering
when taking multiple locks of the same type. This gets rid of
one use of lockdep_set_novalidate_class() in the bcache code.
- Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended
variable shadowing generating garbage code on Clang on certain
ARM builds.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=DsYj
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce cmpxchg128() -- aka. the demise of cmpxchg_double()
The cmpxchg128() family of functions is basically & functionally the
same as cmpxchg_double(), but with a saner interface.
Instead of a 6-parameter horror that forced u128 - u64/u64-halves
layout details on the interface and exposed users to complexity,
fragility & bugs, use a natural 3-parameter interface with u128
types.
- Restructure the generated atomic headers, and add kerneldoc comments
for all of the generic atomic{,64,_long}_t operations.
The generated definitions are much cleaner now, and come with
documentation.
- Implement lock_set_cmp_fn() on lockdep, for defining an ordering when
taking multiple locks of the same type.
This gets rid of one use of lockdep_set_novalidate_class() in the
bcache code.
- Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable
shadowing generating garbage code on Clang on certain ARM builds.
* tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc
percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg()
locking/atomic: treewide: delete arch_atomic_*() kerneldoc
locking/atomic: docs: Add atomic operations to the driver basic API documentation
locking/atomic: scripts: generate kerneldoc comments
docs: scripts: kernel-doc: accept bitwise negation like ~@var
locking/atomic: scripts: simplify raw_atomic*() definitions
locking/atomic: scripts: simplify raw_atomic_long*() definitions
locking/atomic: scripts: split pfx/name/sfx/order
locking/atomic: scripts: restructure fallback ifdeffery
locking/atomic: scripts: build raw_atomic_long*() directly
locking/atomic: treewide: use raw_atomic*_<op>()
locking/atomic: scripts: add trivial raw_atomic*_<op>()
locking/atomic: scripts: factor out order template generation
locking/atomic: scripts: remove leftover "${mult}"
locking/atomic: scripts: remove bogus order parameter
locking/atomic: xtensa: add preprocessor symbols
locking/atomic: x86: add preprocessor symbols
locking/atomic: sparc: add preprocessor symbols
locking/atomic: sh: add preprocessor symbols
...
|
||
|
Linus Torvalds
|
af96134dc8 |
RCU pull request for v6.5
This pull contains the following branches:
doc.2023.05.10a: Documentation updates
fixes.2023.05.11a: Miscellaneous fixes, perhaps most notably:
o Remove RCU_NONIDLE(). The new visibility of most of the idle
loop to RCU has obsoleted this API.
o Make the RCU_SOFTIRQ callback-invocation time limit also apply
to the rcuc kthreads that invoke callbacks for CONFIG_PREEMPT_RT.
o Add a jiffies-based callback-invocation time limit to handle
long-running callbacks. (The local_clock() function is only
invoked once per 32 callbacks due to its high overhead.)
o Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs,
which fixes a bug that can occur on systems with non-contiguous
CPU numbering.
kvfree.2023.05.10a: kvfree_rcu updates
o Eliminate the single-argument variant of k[v]free_rcu() now
that all uses have been converted to k[v]free_rcu_mightsleep().
o Add WARN_ON_ONCE() checks for k[v]free_rcu*() freeing callbacks
too soon. Yes, this is closing the barn door after the horse
has escaped, but Murphy says that there will be more horses.
nocb.2023.05.11a: Callback-offloading updates
o Fix a number of bugs involving the shrinker and lazy callbacks.
rcu-tasks.2023.05.10a: Tasks RCU updates
torture.2023.05.15a: Torture-test updates
rcu-urgent.2023.06.06a: Urgent SRCU fix (already pulled)
-----BEGIN PGP SIGNATURE-----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=3LCd
-----END PGP SIGNATURE-----
Merge tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
"Documentation updates
Miscellaneous fixes, perhaps most notably:
- Remove RCU_NONIDLE(). The new visibility of most of the idle loop
to RCU has obsoleted this API.
- Make the RCU_SOFTIRQ callback-invocation time limit also apply to
the rcuc kthreads that invoke callbacks for CONFIG_PREEMPT_RT.
- Add a jiffies-based callback-invocation time limit to handle
long-running callbacks. (The local_clock() function is only invoked
once per 32 callbacks due to its high overhead.)
- Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs, which
fixes a bug that can occur on systems with non-contiguous CPU
numbering.
kvfree_rcu updates:
- Eliminate the single-argument variant of k[v]free_rcu() now that
all uses have been converted to k[v]free_rcu_mightsleep().
- Add WARN_ON_ONCE() checks for k[v]free_rcu*() freeing callbacks too
soon. Yes, this is closing the barn door after the horse has
escaped, but Murphy says that there will be more horses.
Callback-offloading updates:
- Fix a number of bugs involving the shrinker and lazy callbacks.
Tasks RCU updates
Torture-test updates"
* tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (32 commits)
torture: Remove duplicated argument -enable-kvm for ppc64
doc/rcutorture: Add description of rcutorture.stall_cpu_block
rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale
rcu/rcuscale: Move rcu_scale_*() after kfree_scale_cleanup()
rcutorture: Correct name of use_softirq module parameter
locktorture: Add long_hold to adjust lock-hold delays
rcu/nocb: Make shrinker iterate only over NOCB CPUs
rcu-tasks: Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs
rcu: Make rcu_cpu_starting() rely on interrupts being disabled
rcu: Mark rcu_cpu_kthread() accesses to ->rcu_cpu_has_work
rcu: Mark additional concurrent load from ->cpu_no_qs.b.exp
rcu: Employ jiffies-based backstop to callback time limit
rcu: Check callback-invocation time limit for rcuc kthreads
rcu: Remove RCU_NONIDLE()
rcu: Add more RCU files to kernel-api.rst
rcu-tasks: Clarify the cblist_init_generic() function's pr_info() output
rcu-tasks: Avoid pr_info() with spin lock in cblist_init_generic()
rcu/nocb: Recheck lazy callbacks under the ->nocb_lock from shrinker
rcu/nocb: Fix shrinker race against callback enqueuer
rcu/nocb: Protect lazy shrinker against concurrent (de-)offloading
...
|
||
|
Arnd Bergmann
|
ff7138813a |
locking: add lockevent_read() prototype
lockevent_read() has a __weak definition and the only caller in kernel/locking/lock_events.c, plus a strong definition in qspinlock_stat.h that overrides it, but no other declaration. This causes a W=1 warning: kernel/locking/lock_events.c:61:16: error: no previous prototype for 'lockevent_read' [-Werror=missing-prototypes] Add shared prototype to avoid the warnings. Link: https://lkml.kernel.org/r/20230517131102.934196-7-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Eric Paris <eparis@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Linus Torvalds
|
d8f14b84fe |
Two fixes for debugobjects:
- Prevent that the allocation path wakes up kswapd. That's a long
standing issue due to the GFP_ATOMIC allocation flag. As debug objects
can be invoked from pretty much any context waking kswapd can end up
in arbitrary lock chains versus the waitqueue lock.
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool().
-----BEGIN PGP SIGNATURE-----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=7B4m
-----END PGP SIGNATURE-----
Merge tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull debugobjects fixes from Thomas Gleixner:
"Two fixes for debugobjects:
- Prevent the allocation path from waking up kswapd.
That's a long standing issue due to the GFP_ATOMIC allocation flag.
As debug objects can be invoked from pretty much any context waking
kswapd can end up in arbitrary lock chains versus the waitqueue
lock
- Correct the explicit lockdep wait-type violation in
debug_object_fill_pool()"
* tag 'core-debugobjects-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Don't wake up kswapd from fill_pool()
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
|
||
|
Kent Overstreet
|
eb1cfd09f7 |
lockdep: Add lock_set_cmp_fn() annotation
This implements a new interface to lockdep, lock_set_cmp_fn(), for defining a custom ordering when taking multiple locks of the same class. This is an alternative to subclasses, but can not fully replace them since subclasses allow lock hierarchies with other clasees inter-twined, while this relies on pure class nesting. Specifically, if A is our nesting class then: A/0 <- B <- A/1 Would be a valid lock order with subclasses (each subclass really is a full class from the validation PoV) but not with this annotation, which requires all nesting to be consecutive. Example output: | ============================================ | WARNING: possible recursive locking detected | 6.2.0-rc8-00003-g7d81e591ca6a-dirty #15 Not tainted | -------------------------------------------- | kworker/14:3/938 is trying to acquire lock: | ffff8880143218c8 (&b->lock l=0 0:2803368){++++}-{3:3}, at: bch_btree_node_get.part.0+0x81/0x2b0 | | but task is already holding lock: | ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0 | and the lock comparison function returns 1: | | other info that might help us debug this: | Possible unsafe locking scenario: | | CPU0 | ---- | lock(&b->lock l=1 1048575:9223372036854775807); | lock(&b->lock l=0 0:2803368); | | *** DEADLOCK *** | | May be due to missing lock nesting notation | | 3 locks held by kworker/14:3/938: | #0: ffff888005ea9d38 ((wq_completion)bcache){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530 | #1: ffff8880098c3e70 ((work_completion)(&cl->work)#3){+.+.}-{0:0}, at: process_one_work+0x1ec/0x530 | #2: ffff8880143de8c8 (&b->lock l=1 1048575:9223372036854775807){++++}-{3:3}, at: __bch_btree_map_nodes+0xea/0x1e0 [peterz: extended changelog] Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230509195847.1745548-1-kent.overstreet@linux.dev |
||
|
Paul E. McKenney
|
f8619c300f |
locktorture: Add long_hold to adjust lock-hold delays
This commit adds a long_hold module parameter to allow testing diagnostics for excessive lock-hold times. Also adjust torture_param() invocations for longer line length while in the area. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> |
||
|
John Stultz
|
92cc5d00a4 |
locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers
Apparently despite it being marked inline, the compiler
may not inline __down_read_common() which makes it difficult
to identify the cause of lock contention, as the blocked
function in traceevents will always be listed as
__down_read_common().
So this patch adds __always_inline annotation to the common
function (as well as the inlined helper callers) to force it to
be inlined so the blocking function will be listed (via Wchan)
in traceevents.
Fixes:
|
||
|
Linus Torvalds
|
b115d85a95 |
Locking changes in v6.4:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code.
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation.
- Misc cleanups/fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=mM0A
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation
- Misc cleanups/fixes
* tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/atomic: Correct (cmp)xchg() instrumentation
locking/x86: Define arch_try_cmpxchg_local()
locking/arch: Wire up local_try_cmpxchg()
locking/generic: Wire up local{,64}_try_cmpxchg()
locking/atomic: Add generic try_cmpxchg{,64}_local() support
locking/rwbase: Mitigate indefinite writer starvation
locking/arch: Rename all internal __xchg() names to __arch_xchg()
|
||
|
Peter Zijlstra
|
0cce06ba85 |
debugobjects,locking: Annotate debug_object_fill_pool() wait type violation
There is an explicit wait-type violation in debug_object_fill_pool() for PREEMPT_RT=n kernels which allows them to more easily fill the object pool and reduce the chance of allocation failures. Lockdep's wait-type checks are designed to check the PREEMPT_RT locking rules even for PREEMPT_RT=n kernels and object to this, so create a lockdep annotation to allow this to stand. Specifically, create a 'lock' type that overrides the inner wait-type while it is held -- allowing one to temporarily raise it, such that the violation is hidden. Reported-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Qi Zheng <zhengqi.arch@bytedance.com> Link: https://lkml.kernel.org/r/20230429100614.GA1489784@hirez.programming.kicks-ass.net |
||
|
Sebastian Andrzej Siewior
|
286deb7ec0 |
locking/rwbase: Mitigate indefinite writer starvation
On PREEMPT_RT, rw_semaphore and rwlock_t locks are unfair to writers. Readers can indefinitely acquire the lock unless the writer fully acquired the lock, which might never happen if there is always a reader in the critical section owning the lock. Mel Gorman reported that since LTP-20220121 the dio_truncate test case went from having 1 reader to having 16 readers and that number of readers is sufficient to prevent the down_write ever succeeding while readers exist. Eventually the test is killed after 30 minutes as a failure. Mel proposed a timeout to limit how long a writer can be blocked until the reader is forced into the slowpath. Thomas argued that there is no added value by providing this timeout. From a PREEMPT_RT point of view, there are no critical rw_semaphore or rwlock_t locks left where the reader must be preferred. Mitigate indefinite writer starvation by forcing the READER into the slowpath once the WRITER attempts to acquire the lock. Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: https://lore.kernel.org/877cwbq4cq.ffs@tglx Link: https://lore.kernel.org/r/20230321161140.HMcQEhHb@linutronix.de Cc: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
5dfb75e842 |
RCU Changes for 6.4:
o MAINTAINERS files additions and changes.
o Fix hotplug warning in nohz code.
o Tick dependency changes by Zqiang.
o Lazy-RCU shrinker fixes by Zqiang.
o rcu-tasks stall reporting improvements by Neeraj.
o Initial changes for renaming of k[v]free_rcu() to its new k[v]free_rcu_mightsleep()
name for robustness.
o Documentation Updates:
o Significant changes to srcu_struct size.
o Deadlock detection for srcu_read_lock() vs synchronize_srcu() from Boqun.
o rcutorture and rcu-related tool, which are targeted for v6.4 from Boqun's tree.
o Other misc changes.
-----BEGIN PGP SIGNATURE-----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=Rgbj
-----END PGP SIGNATURE-----
Merge tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux
Pull RCU updates from Joel Fernandes:
- Updates and additions to MAINTAINERS files, with Boqun being added to
the RCU entry and Zqiang being added as an RCU reviewer.
I have also transitioned from reviewer to maintainer; however, Paul
will be taking over sending RCU pull-requests for the next merge
window.
- Resolution of hotplug warning in nohz code, achieved by fixing
cpu_is_hotpluggable() through interaction with the nohz subsystem.
Tick dependency modifications by Zqiang, focusing on fixing usage of
the TICK_DEP_BIT_RCU_EXP bitmask.
- Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
kernels, fixed by Zqiang.
- Improvements to rcu-tasks stall reporting by Neeraj.
- Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
increased robustness, affecting several components like mac802154,
drbd, vmw_vmci, tracing, and more.
A report by Eric Dumazet showed that the API could be unknowingly
used in an atomic context, so we'd rather make sure they know what
they're asking for by being explicit:
https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/
- Documentation updates, including corrections to spelling,
clarifications in comments, and improvements to the srcu_size_state
comments.
- Better srcu_struct cache locality for readers, by adjusting the size
of srcu_struct in support of SRCU usage by Christoph Hellwig.
- Teach lockdep to detect deadlocks between srcu_read_lock() vs
synchronize_srcu() contributed by Boqun.
Previously lockdep could not detect such deadlocks, now it can.
- Integration of rcutorture and rcu-related tools, targeted for v6.4
from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
module parameter, and more
- Miscellaneous changes, various code cleanups and comment improvements
* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
checkpatch: Error out if deprecated RCU API used
mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
rcu/trace: use strscpy() to instead of strncpy()
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
...
|
||
|
Boqun Feng
|
0471db447c |
locking/lockdep: Improve the deadlock scenario print for sync and read lock
Lock scenario print is always a weak spot of lockdep splats. Improvement can be made if we rework the dependency search and the error printing. However without touching the graph search, we can improve a little for the circular deadlock case, since we have the to-be-added lock dependency, and know whether these two locks are read/write/sync. In order to know whether a held_lock is sync or not, a bit was "stolen" from ->references, which reduce our limit for the same lock class nesting from 2^12 to 2^11, and it should still be good enough. Besides, since we now have bit in held_lock for sync, we don't need the "hardirqoffs being 1" trick, and also we can avoid the __lock_release() if we jump out of __lock_acquire() before the held_lock stored. With these changes, a deadlock case evolved with read lock and sync gets a better print-out from: [...] Possible unsafe locking scenario: [...] [...] CPU0 CPU1 [...] ---- ---- [...] lock(srcuA); [...] lock(srcuB); [...] lock(srcuA); [...] lock(srcuB); to [...] Possible unsafe locking scenario: [...] [...] CPU0 CPU1 [...] ---- ---- [...] rlock(srcuA); [...] lock(srcuB); [...] lock(srcuA); [...] sync(srcuB); Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> |
||
|
Boqun Feng
|
60a1a64ec0 |
locking: Reduce the number of locks in ww_mutex stress tests
The stress test in test_ww_mutex_init() uses 4095 locks since lockdep::reference has 12 bits, and since we are going to reduce it to 11 bits to support lock_sync(), and 2047 is still a reasonable number of the max nesting level for locks, so adjust the test. Reported-by: kernel test robot <oliver.sang@intel.com> Link: https://lore.kernel.org/oe-lkp/202302011445.9d99dae2-oliver.sang@intel.com Tested-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> |
||
|
Boqun Feng
|
2f1f043e7b |
locking/lockdep: Introduce lock_sync()
Currently, functions like synchronize_srcu() do not have lockdep
annotations resembling those of other write-side locking primitives.
Such annotations might look as follows:
lock_acquire();
lock_release();
Such annotations would tell lockdep that synchronize_srcu() acts like
an empty critical section that waits for other (read-side) critical
sections to finish. This would definitely catch some deadlock, but
as pointed out by Paul Mckenney [1], this could also introduce false
positives because of irq-safe/unsafe detection. Of course, there are
tricks could help with this:
might_sleep(); // Existing statement in __synchronize_srcu().
if (IS_ENABLED(CONFIG_PROVE_LOCKING)) {
local_irq_disable();
lock_acquire();
lock_release();
local_irq_enable();
}
But it would be better for lockdep to provide a separate annonation for
functions like synchronize_srcu(), so that people won't need to repeat
the ugly tricks above.
Therefore introduce lock_sync(), which is simply an lock+unlock
pair with no irq safe/unsafe deadlock check. This works because the
to-be-annontated functions do not create real critical sections, and
there is therefore no way that irq can create extra dependencies.
[1]: https://lore.kernel.org/lkml/20180412021233.ewncg5jjuzjw3x62@tardis/
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ boqun: Fix typos reported by Davidlohr Bueso and Paul E. Mckenney ]
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
|
||
|
Zqiang
|
5d65cf6ae6 |
locktorture: Add raw_spinlock* torture tests for PREEMPT_RT kernels
In PREEMPT_RT kernels, both spin_lock() and spin_lock_irq() are converted to sleepable rt_spin_lock(). This means that the interrupt related suffixes for spin_lock/unlock(_irq, irqsave/irqrestore) do not affect the CPU's interrupt state. This commit therefore adds raw spin-lock torture tests. This in turn permits pure spin locks to be tested in PREEMPT_RT kernels. Suggested-by: Paul E. McKenney <paulmck@kernel.org> Suggested-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Zqiang <qiang1.zhang@intel.com> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
45bcf0bd8c |
locktorture: With nested locks, occasionally skip main lock
If we're using nested locking to stress things, occasionally skip taking the main lock, so that we can get some different contention patterns between the writers (to hopefully get two disjoint blocked trees) Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
ae4823e427 |
locktorture: Add nested locking to rtmutex torture tests
This patch adds randomized nested locking to the rtmutex torture tests. Additionally it adds LOCK09 config files for testing rtmutexes with nested locking. Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
3e5aeaf534 |
locktorture: Add nested locking to mutex torture tests
This patch adds randomized nested locking to the mutex torture tests, as well as new LOCK08 config files for testing mutexes with nested locking Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
John Stultz
|
b63343207d |
locktorture: Add nested_[un]lock() hooks and nlocks parameter
In order to extend locktorture to support lock nesting, add nested_lock() and nested_unlock() hooks to the torture ops. These take a 32bit lockset mask which is generated at random, so some number of locks will be taken before the main lock is taken and released afterwards. Additionally, add nested_locks module parameter to allow specifying the number of nested locks to be used. This has been helpful to uncover issues in the proxy-exec series development. This was inspired by locktorture extensions originally implemented by Connor O'Brien, for stress testing the proxy-execution series: https://lore.kernel.org/lkml/20221003214501.2050087-12-connoro@google.com/ Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: kernel-team@android.com Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Co-developed-by: Connor O'Brien <connoro@google.com> Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Linus Torvalds
|
8cc01d43f8 |
RCU pull request for v6.3
This pull request contains the following branches:
doc.2023.01.05a: Documentation updates.
fixes.2023.01.23a: Miscellaneous fixes, perhaps most notably:
o Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number
of callbacks.
o Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized.
o Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have doen this for mnay years.)
o Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled,
so this should not (yet) affect production use cases.)
kvfree.2023.01.03a: Cause kfree_rcu() and friends to take advantage of
polled grace periods, thus reducing memory footprint by almost
two orders of magnitude, admittedly on a microbenchmark.
This series also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs
where kfree_rcu(p), which can block, was typed instead of the
intended kfree_rcu(p, rh).
srcu.2023.01.03a: SRCU updates, perhaps most notably fixing a bug that
causes SRCU to fail when booted on a system with a non-zero boot
CPU. This surprising situation actually happens for kdump kernels
on the powerpc architecture. It also adds an srcu_down_read()
and srcu_up_read(), which act like srcu_read_lock() and
srcu_read_unlock(), but allow an SRCU read-side critical section
to be handed off from one task to another.
srcu-always.2023.02.02a: Cleans up the now-useless SRCU Kconfig option.
There are a few more commits that are not yet acked or pulled
into maintainer trees, and these will be in a pull request for
a later merge window.
tasks.2023.01.03a: RCU-tasks updates, perhaps most notably these fixes:
o A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang.
o A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can result
in a too-short grace period.
o A race between shrinking RCU tasks down to a single callback list
and queuing a new callback to some other CPU, but where that
queuing is delayed for more than an RCU grace period. This can
result in that callback being stranded on the non-boot CPU.
torture.2023.01.05a: Torture-test updates and fixes.
torturescript.2023.01.03a: Torture-test scripting updates and fixes.
stall.2023.01.09a: Provide additional RCU CPU stall-warning information
in kernels built with CONFIG_RCU_CPU_STALL_CPUTIME=y, and
restore the full five-minute timeout limit for expedited RCU
CPU stall warnings.
-----BEGIN PGP SIGNATURE-----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=bBYK
-----END PGP SIGNATURE-----
Merge tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney:
- Documentation updates
- Miscellaneous fixes, perhaps most notably:
- Throttling callback invocation based on the number of callbacks
that are now ready to invoke instead of on the total number of
callbacks
- Several patches that suppress false-positive boot-time
diagnostics, for example, due to lockdep not yet being
initialized
- Make expedited RCU CPU stall warnings dump stacks of any tasks
that are blocking the stalled grace period. (Normal RCU CPU
stall warnings have done this for many years)
- Lazy-callback fixes to avoid delays during boot, suspend, and
resume. (Note that lazy callbacks must be explicitly enabled, so
this should not (yet) affect production use cases)
- Make kfree_rcu() and friends take advantage of polled grace periods,
thus reducing memory footprint by almost two orders of magnitude,
admittedly on a microbenchmark
This also begins the transition from kfree_rcu(p) to
kfree_rcu_mightsleep(p). This transition was motivated by bugs where
kfree_rcu(p), which can block, was typed instead of the intended
kfree_rcu(p, rh)
- SRCU updates, perhaps most notably fixing a bug that causes SRCU to
fail when booted on a system with a non-zero boot CPU. This
surprising situation actually happens for kdump kernels on the
powerpc architecture
This also adds an srcu_down_read() and srcu_up_read(), which act like
srcu_read_lock() and srcu_read_unlock(), but allow an SRCU read-side
critical section to be handed off from one task to another
- Clean up the now-useless SRCU Kconfig option
There are a few more commits that are not yet acked or pulled into
maintainer trees, and these will be in a pull request for a later
merge window
- RCU-tasks updates, perhaps most notably these fixes:
- A strange interaction between PID-namespace unshare and the
RCU-tasks grace period that results in a low-probability but
very real hang
- A race between an RCU tasks rude grace period on a single-CPU
system and CPU-hotplug addition of the second CPU that can
result in a too-short grace period
- A race between shrinking RCU tasks down to a single callback
list and queuing a new callback to some other CPU, but where
that queuing is delayed for more than an RCU grace period. This
can result in that callback being stranded on the non-boot CPU
- Torture-test updates and fixes
- Torture-test scripting updates and fixes
- Provide additional RCU CPU stall-warning information in kernels built
with CONFIG_RCU_CPU_STALL_CPUTIME=y, and restore the full five-minute
timeout limit for expedited RCU CPU stall warnings
* tag 'rcu.2023.02.10a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (80 commits)
rcu/kvfree: Add kvfree_rcu_mightsleep() and kfree_rcu_mightsleep()
kernel/notifier: Remove CONFIG_SRCU
init: Remove "select SRCU"
fs/quota: Remove "select SRCU"
fs/notify: Remove "select SRCU"
fs/btrfs: Remove "select SRCU"
fs: Remove CONFIG_SRCU
drivers/pci/controller: Remove "select SRCU"
drivers/net: Remove "select SRCU"
drivers/md: Remove "select SRCU"
drivers/hwtracing/stm: Remove "select SRCU"
drivers/dax: Remove "select SRCU"
drivers/base: Remove CONFIG_SRCU
rcu: Disable laziness if lazy-tracking says so
rcu: Track laziness during boot and suspend
rcu: Remove redundant call to rcu_boost_kthread_setaffinity()
rcu: Allow up to five minutes expedited RCU CPU stall-warning timeouts
rcu: Align the output of RCU CPU stall warning messages
rcu: Add RCU stall diagnosis information
sched: Add helper nr_context_switches_cpu()
...
|
||
|
Linus Torvalds
|
1f2d9ffc7a |
Scheduler updates in this cycle are:
- Improve the scalability of the CFS bandwidth unthrottling logic
with large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with
the generic scheduler code. Add __cpuidle methods as noinstr to
objtool's noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS,
to query previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period,
to improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- ... Misc other cleanups, fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=l1nN
-----END PGP SIGNATURE-----
Merge tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Improve the scalability of the CFS bandwidth unthrottling logic with
large number of CPUs.
- Fix & rework various cpuidle routines, simplify interaction with the
generic scheduler code. Add __cpuidle methods as noinstr to objtool's
noinstr detection and fix boatloads of cpuidle bugs & quirks.
- Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query
previously issued registrations.
- Limit scheduler slice duration to the sysctl_sched_latency period, to
improve scheduling granularity with a large number of SCHED_IDLE
tasks.
- Debuggability enhancement on sys_exit(): warn about disabled IRQs,
but also enable them to prevent a cascade of followup problems and
repeat warnings.
- Fix the rescheduling logic in prio_changed_dl().
- Micro-optimize cpufreq and sched-util methods.
- Micro-optimize ttwu_runnable()
- Micro-optimize the idle-scanning in update_numa_stats(),
select_idle_capacity() and steal_cookie_task().
- Update the RSEQ code & self-tests
- Constify various scheduler methods
- Remove unused methods
- Refine __init tags
- Documentation updates
- Misc other cleanups, fixes
* tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits)
sched/rt: pick_next_rt_entity(): check list_entry
sched/deadline: Add more reschedule cases to prio_changed_dl()
sched/fair: sanitize vruntime of entity being placed
sched/fair: Remove capacity inversion detection
sched/fair: unlink misfit task from cpu overutilized
objtool: mem*() are not uaccess safe
cpuidle: Fix poll_idle() noinstr annotation
sched/clock: Make local_clock() noinstr
sched/clock/x86: Mark sched_clock() noinstr
x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read()
x86/atomics: Always inline arch_atomic64*()
cpuidle: tracing, preempt: Squash _rcuidle tracing
cpuidle: tracing: Warn about !rcu_is_watching()
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
cpuidle: drivers: firmware: psci: Dont instrument suspend code
KVM: selftests: Fix build of rseq test
exit: Detect and fix irq disabled state in oops
cpuidle, arm64: Fix the ARM64 cpuidle logic
cpuidle: mvebu: Fix duplicate flags assignment
sched/fair: Limit sched slice duration
...
|
||
|
Linus Torvalds
|
6e649d0856 |
Updates for this cycle were:
- rwsem micro-optimizations
- spinlock micro-optimizations
- cleanups, simplifications
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=yTly
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- rwsem micro-optimizations
- spinlock micro-optimizations
- cleanups, simplifications
* tag 'locking-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
vduse: Remove include of rwlock.h
locking/lockdep: Remove lockdep_init_map_crosslock.
x86/ACPI/boot: Use try_cmpxchg() in __acpi_{acquire,release}_global_lock()
x86/PAT: Use try_cmpxchg() in set_page_memtype()
locking/rwsem: Disable preemption in all down_write*() and up_write() code paths
locking/rwsem: Disable preemption in all down_read*() and up_read() code paths
locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
locking/qspinlock: Micro-optimize pending state waiting for unlock
|
||
|
Wander Lairson Costa
|
db370a8b9f |
rtmutex: Ensure that the top waiter is always woken up
Let L1 and L2 be two spinlocks.
Let T1 be a task holding L1 and blocked on L2. T1, currently, is the top
waiter of L2.
Let T2 be the task holding L2.
Let T3 be a task trying to acquire L1.
The following events will lead to a state in which the wait queue of L2
isn't empty, but no task actually holds the lock.
T1 T2 T3
== == ==
spin_lock(L1)
| raw_spin_lock(L1->wait_lock)
| rtlock_slowlock_locked(L1)
| | task_blocks_on_rt_mutex(L1, T3)
| | | orig_waiter->lock = L1
| | | orig_waiter->task = T3
| | | raw_spin_unlock(L1->wait_lock)
| | | rt_mutex_adjust_prio_chain(T1, L1, L2, orig_waiter, T3)
spin_unlock(L2) | | | |
| rt_mutex_slowunlock(L2) | | | |
| | raw_spin_lock(L2->wait_lock) | | | |
| | wakeup(T1) | | | |
| | raw_spin_unlock(L2->wait_lock) | | | |
| | | | waiter = T1->pi_blocked_on
| | | | waiter == rt_mutex_top_waiter(L2)
| | | | waiter->task == T1
| | | | raw_spin_lock(L2->wait_lock)
| | | | dequeue(L2, waiter)
| | | | update_prio(waiter, T1)
| | | | enqueue(L2, waiter)
| | | | waiter != rt_mutex_top_waiter(L2)
| | | | L2->owner == NULL
| | | | wakeup(T1)
| | | | raw_spin_unlock(L2->wait_lock)
T1 wakes up
T1 != top_waiter(L2)
schedule_rtlock()
If the deadline of T1 is updated before the call to update_prio(), and the
new deadline is greater than the deadline of the second top waiter, then
after the requeue, T1 is no longer the top waiter, and the wrong task is
woken up which will then go back to sleep because it is not the top waiter.
This can be reproduced in PREEMPT_RT with stress-ng:
while true; do
stress-ng --sched deadline --sched-period 1000000000 \
--sched-runtime 800000000 --sched-deadline \
1000000000 --mmapfork 23 -t 20
done
A similar issue was pointed out by Thomas versus the cases where the top
waiter drops out early due to a signal or timeout, which is a general issue
for all regular rtmutex use cases, e.g. futex.
The problematic code is in rt_mutex_adjust_prio_chain():
// Save the top waiter before dequeue/enqueue
prerequeue_top_waiter = rt_mutex_top_waiter(lock);
rt_mutex_dequeue(lock, waiter);
waiter_update_prio(waiter, task);
rt_mutex_enqueue(lock, waiter);
// Lock has no owner?
if (!rt_mutex_owner(lock)) {
// Top waiter changed
----> if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
----> wake_up_state(waiter->task, waiter->wake_state);
This only takes the case into account where @waiter is the new top waiter
due to the requeue operation.
But it fails to handle the case where @waiter is not longer the top
waiter due to the requeue operation.
Ensure that the new top waiter is woken up so in all cases so it can take
over the ownerless lock.
[ tglx: Amend changelog, add Fixes tag ]
Fixes:
|
||
|
Peter Zijlstra
|
5a5d7e9bad |
cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG
In order to avoid WARN/BUG from generating nested or even recursive warnings, force rcu_is_watching() true during WARN/lockdep_rcu_suspicious(). Notably things like unwinding the stack can trigger rcu_dereference() warnings, which then triggers more unwinding which then triggers more warnings etc.. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230126151323.408156109@infradead.org |
||
|
Waiman Long
|
1d61659ced |
locking/rwsem: Disable preemption in all down_write*() and up_write() code paths
The previous patch has disabled preemption in all the down_read() and
up_read() code paths. For symmetry, this patch extends commit:
|
||
|
Waiman Long
|
3f5245538a |
locking/rwsem: Disable preemption in all down_read*() and up_read() code paths
Commit: |
||
|
Waiman Long
|
b613c7f314 |
locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
A non-first waiter can potentially spin in the for loop of
rwsem_down_write_slowpath() without sleeping but fail to acquire the
lock even if the rwsem is free if the following sequence happens:
Non-first RT waiter First waiter Lock holder
------------------- ------------ -----------
Acquire wait_lock
rwsem_try_write_lock():
Set handoff bit if RT or
wait too long
Set waiter->handoff_set
Release wait_lock
Acquire wait_lock
Inherit waiter->handoff_set
Release wait_lock
Clear owner
Release lock
if (waiter.handoff_set) {
rwsem_spin_on_owner(();
if (OWNER_NULL)
goto trylock_again;
}
trylock_again:
Acquire wait_lock
rwsem_try_write_lock():
if (first->handoff_set && (waiter != first))
return false;
Release wait_lock
A non-first waiter cannot really acquire the rwsem even if it mistakenly
believes that it can spin on OWNER_NULL value. If that waiter happens
to be an RT task running on the same CPU as the first waiter, it can
block the first waiter from acquiring the rwsem leading to live lock.
Fix this problem by making sure that a non-first waiter cannot spin in
the slowpath loop without sleeping.
Fixes:
|
||
|
Joel Fernandes (Google)
|
c24501b240 |
locktorture: Make the rt_boost factor a tunable
The rt boosting in locktorture has a factor variable s currently large enough that boosting only happens once every minute or so. Add a tunable to reduce the factor so that boosting happens more often, to test paths and arrive at failure modes earlier. With this change, I can set the factor to like 50 and have the boosting happens every 10 seconds or so. Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=50 locktorture.nlocks=3 Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Joel Fernandes (Google)
|
e01f3a1a58 |
locktorture: Allow non-rtmutex lock types to be boosted
Currently RT boosting is only done for rtmutex_lock, however with proxy execution, we also have the mutex_lock participating in priorities. To exercise the testing better, add RT boosting to other lock testing types as well, using a new knob (rt_boost). Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=1 locktorture.nlocks=3 Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
||
|
Guo Ren
|
4282494a20 |
locking/qspinlock: Micro-optimize pending state waiting for unlock
When we're pending, we only care about lock value. The xchg_tail wouldn't affect the pending state. That means the hardware thread could stay in a sleep state and leaves the rest execution units' resources of pipeline to other hardware threads. This situation is the SMT scenarios in the same core. Not an entering low-power state situation. Of course, the granularity between cores is "cacheline", but the granularity between SMT hw threads of the same core could be "byte" which internal LSU handles. For example, when a hw-thread yields the resources of the core to other hw-threads, this patch could help the hw-thread stay in the sleep state and prevent it from being woken up by other hw-threads xchg_tail. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20230105021952.3090070-1-guoren@kernel.org Cc: Peter Zijlstra <peterz@infradead.org> |
||
|
Linus Torvalds
|
95d248d16f |
- Prevent the leaking of a debug timer in futex_waitv()
- A preempt-RT mutex locking fix, adding the proper acquire semantics -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmOxn1cACgkQEsHwGGHe VUp+AQ/9GilVlaWqloC+sDK/7qTLfmQjR/XwQPii2pMBUO1oRFT7mG+dG7lKNpRL WCLTVIrzG528ORJytvMGuqx+CqenuTGPFI9rtizxdtRlNZyiS33hvlaGBPY7XYY7 G2qugGKuZ7WVKZpq6szPwnrMuWjdsd+XOO+NE3h/5kI2T7ZukmlXl9/EtVii7+y3 LGVjMhN+R0XCMCPSSPtFx5eUGalemPnGSBcX/Qb4zG1MphSPURFKHEQmWHZzgrkg 6fmqx773u2mquxTYeEy0FDLjOYFEHlzDFgRtIDBaziHIxjzO/5r09m8RDF2mXetW W/pf/Iduh2TZWwJDngmUi0JxqOzz0l8T/6vSCuArYWkjb+0zDOPHuCYwif2iHAQo pMn+O5nAtLMZhdk+yjTs4abQ11q9owLh0nGps4A2SKgJIH0mL2BICwRotzuV1sxf CGnoOxIxZuZGq8xMoHp6sJ8e4RnJHBAt7PKrCsLTkPAjKjgmBpqshVav//kyCFeY 2R4rgRY/a42Z86uNSysVnxxkop4vRgTZ3l7TijzyeIbycI7v9WMADk0TKTDgsMbL nEnlZPWXJGYNXH71ZPV5TPgidHfiO68sVKerXWRrWRLyGHhY2TC67Lz29vTAlbMK NdOM6pO0DkaKSLxEJ6qso819ePnRA/2O5B7xU/Ll7vONjCpHlFw= =9LHF -----END PGP SIGNATURE----- Merge tag 'locking_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Borislav Petkov: - Prevent the leaking of a debug timer in futex_waitv() - A preempt-RT mutex locking fix, adding the proper acquire semantics * tag 'locking_urgent_for_v6.2_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Fix futex_waitv() hrtimer debug object leak on kcalloc error rtmutex: Add acquire semantics for rtmutex lock acquisition slow path |
||
|
Linus Torvalds
|
e2ca6ba6ba |
MM patches for 6.2-rc1.
- More userfaultfs work from Peter Xu. - Several convert-to-folios series from Sidhartha Kumar and Huang Ying. - Some filemap cleanups from Vishal Moola. - David Hildenbrand added the ability to selftest anon memory COW handling. - Some cpuset simplifications from Liu Shixin. - Addition of vmalloc tracing support by Uladzislau Rezki. - Some pagecache folioifications and simplifications from Matthew Wilcox. - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it. - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series shold have been in the non-MM tree, my bad. - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages. - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages. - Peter Xu utilized the PTE marker code for handling swapin errors. - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient. - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand. - zram support for multiple compression streams from Sergey Senozhatsky. - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway. - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations. - Vishal Moola removed the try_to_release_page() wrapper. - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache. - David Hildenbrand did some cleanup and repair work on KSM COW breaking. - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend. - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range(). - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen. - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect. - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages(). - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting. - David Hildenbrand has fixed some of our MM selftests for 32-bit machines. - Many singleton patches, as usual. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY5j6ZwAKCRDdBJ7gKXxA jkDYAP9qNeVqp9iuHjZNTqzMXkfmJPsw2kmy2P+VdzYVuQRcJgEAgoV9d7oMq4ml CodAgiA51qwzId3GRytIo/tfWZSezgA= =d19R -----END PGP SIGNATURE----- Merge tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ... |
||
|
Mel Gorman
|
1c0908d8e4 |
rtmutex: Add acquire semantics for rtmutex lock acquisition slow path
Jan Kara reported the following bug triggering on 6.0.5-rt14 running dbench on XFS on arm64. kernel BUG at fs/inode.c:625! Internal error: Oops - BUG: 0 [#1] PREEMPT_RT SMP CPU: 11 PID: 6611 Comm: dbench Tainted: G E 6.0.0-rt14-rt+ #1 pc : clear_inode+0xa0/0xc0 lr : clear_inode+0x38/0xc0 Call trace: clear_inode+0xa0/0xc0 evict+0x160/0x180 iput+0x154/0x240 do_unlinkat+0x184/0x300 __arm64_sys_unlinkat+0x48/0xc0 el0_svc_common.constprop.4+0xe4/0x2c0 do_el0_svc+0xac/0x100 el0_svc+0x78/0x200 el0t_64_sync_handler+0x9c/0xc0 el0t_64_sync+0x19c/0x1a0 It also affects 6.1-rc7-rt5 and affects a preempt-rt fork of 5.14 so this is likely a bug that existed forever and only became visible when ARM support was added to preempt-rt. The same problem does not occur on x86-64 and he also reported that converting sb->s_inode_wblist_lock to raw_spinlock_t makes the problem disappear indicating that the RT spinlock variant is the problem. Which in turn means that RT mutexes on ARM64 and any other weakly ordered architecture are affected by this independent of RT. Will Deacon observed: "I'd be more inclined to be suspicious of the slowpath tbh, as we need to make sure that we have acquire semantics on all paths where the lock can be taken. Looking at the rtmutex code, this really isn't obvious to me -- for example, try_to_take_rt_mutex() appears to be able to return via the 'takeit' label without acquire semantics and it looks like we might be relying on the caller's subsequent _unlock_ of the wait_lock for ordering, but that will give us release semantics which aren't correct." Sebastian Andrzej Siewior prototyped a fix that does work based on that comment but it was a little bit overkill and added some fences that should not be necessary. The lock owner is updated with an IRQ-safe raw spinlock held, but the spin_unlock does not provide acquire semantics which are needed when acquiring a mutex. Adds the necessary acquire semantics for lock owner updates in the slow path acquisition and the waiter bit logic. It successfully completed 10 iterations of the dbench workload while the vanilla kernel fails on the first iteration. [ bigeasy@linutronix.de: Initial prototype fix ] Fixes: |
||
|
Alexander Potapenko
|
1e8e4a7cc2 |
lockdep: allow instrumenting lockdep.c with KMSAN
Lockdep and KMSAN used to play badly together, causing deadlocks when KMSAN instrumentation of lockdep.c called lockdep functions recursively. Looks like this is no more the case, and a kernel can run (yet slower) with both KMSAN and lockdep enabled. This patch should fix false positives on wq_head->lock->dep_map, which KMSAN used to consider uninitialized because of lockdep.c not being instrumented. Link: https://lore.kernel.org/lkml/Y3b9AAEKp2Vr3e6O@sol.localdomain/ Link: https://lkml.kernel.org/r/20221128094541.2645890-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Eric Biggers <ebiggers@kernel.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Marco Elver <elver@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Jason A. Donenfeld
|
8032bf1233 |
treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> |
||
|
Jason A. Donenfeld
|
81895a65ec |
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
|
||
|
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
|
3e71f0167b |
Locking changes for v6.1:
- Disable preemption in rwsem_write_trylock()'s attempt to
take the rwsem, to avoid RT tasks hogging the CPU, which
managed to preempt this function after the owner has
been cleared but before a new owner is set. Also add
debug checks to enforce this.
- Add __lockfunc to more slow path functions and add
__sched to semaphore functions.
- Mark spinlock APIs noinline when the respective CONFIG_INLINE_SPIN_*
toggles are disabled, to reduce LTO text size.
- Print more debug information when lockdep gets confused
in look_up_lock_class().
- Improve header file abuse checks.
- Misc cleanups
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=we4n
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Disable preemption in rwsem_write_trylock()'s attempt to take the
rwsem, to avoid RT tasks hogging the CPU, which managed to preempt
this function after the owner has been cleared but before a new owner
is set. Also add debug checks to enforce this.
- Add __lockfunc to more slow path functions and add __sched to
semaphore functions.
- Mark spinlock APIs noinline when the respective CONFIG_INLINE_SPIN_*
toggles are disabled, to reduce LTO text size.
- Print more debug information when lockdep gets confused in
look_up_lock_class().
- Improve header file abuse checks.
- Misc cleanups
* tag 'locking-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Print more debug information - report name and key when look_up_lock_class() got confused
locking: Add __sched to semaphore functions
locking/rwsem: Disable preemption while trying for rwsem lock
locking: Detect includes rwlock.h outside of spinlock.h
locking: Add __lockfunc to slow path functions
locking/spinlocks: Mark spinlocks noinline when inline spinlocks are disabled
selftests: futex: Fix 'the the' typo in comment
|
||
|
Alexander Potapenko
|
79dbd006a6 |
kmsan: disable instrumentation of unsupported common kernel code
EFI stub cannot be linked with KMSAN runtime, so we disable instrumentation for it. Instrumenting kcov, stackdepot or lockdep leads to infinite recursion caused by instrumentation hooks calling instrumented code again. Link: https://lkml.kernel.org/r/20220915150417.722975-13-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Tetsuo Handa
|
76e64c73db |
locking/lockdep: Print more debug information - report name and key when look_up_lock_class() got confused
Printing this information will be helpful: ------------[ cut here ]------------ Looking for class "l2tp_sock" with key l2tp_socket_class, but found a different class "slock-AF_INET6" with the same key WARNING: CPU: 1 PID: 14195 at kernel/locking/lockdep.c:940 look_up_lock_class+0xcc/0x140 Modules linked in: CPU: 1 PID: 14195 Comm: a.out Not tainted 6.0.0-rc6-dirty #863 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 RIP: 0010:look_up_lock_class+0xcc/0x140 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/bd99391e-f787-efe9-5ec6-3c6dc4c587b0@I-love.SAKURA.ne.jp |
||
|
Ingo Molnar
|
74656d03ac |
Linux 6.0-rc6
-----BEGIN PGP SIGNATURE----- iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmMngx4eHHRvcnZhbGRz QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGQ1AH/1p4oOT4iqaoTueO MaTQhyvFFcTSLL4y1qejtytNXe4ZEJHyf03jrwtYlfx8RROkZFMJh15G1uWu2deu 43XsUuSWpJ18/C7hRNl1LUazBbuQe30d09zLe7dvD64IAABU6/iQCIorxheTl4EU NXsda2egJUIbTwn2zdFSgMMJPNORxq8KHgvNY/psIEteC+lFln2l2ZXZ21JAIdBj lcTbvx6JpJC0AqX1UuO6NsN4nUnEEh110UtYF6lxQ7olkQKwRaUjQIVuWOFLz75n wDrJxPlVGbDR5zeitDaHkKqWn8LNcqHpDIuAKMxTjT0N/1/sUwHNkyGZXyy1EDJu e0+SX1c= =ITjo -----END PGP SIGNATURE----- Merge tag 'v6.0-rc6' into locking/core, to refresh the branch Signed-off-by: Ingo Molnar <mingo@kernel.org> |
||
|
Namhyung Kim
|
0d97db0265 |
locking: Add __sched to semaphore functions
The internal functions are marked with __sched already, let's do the same for external functions too so that we can skip them in the stack trace. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220909000803.4181857-1-namhyung@kernel.org |
||
|
Gokul krishna Krishnakumar
|
48dfb5d256 |
locking/rwsem: Disable preemption while trying for rwsem lock
Make the region inside the rwsem_write_trylock non preemptible.
We observe RT task is hogging CPU when trying to acquire rwsem lock
which was acquired by a kworker task but before the rwsem owner was set.
Here is the scenario:
1. CFS task (affined to a particular CPU) takes rwsem lock.
2. CFS task gets preempted by a RT task before setting owner.
3. RT task (FIFO) is trying to acquire the lock, but spinning until
RT throttling happens for the lock as the lock was taken by CFS task.
This patch attempts to fix the above issue by disabling preemption
until owner is set for the lock. While at it also fix the issues
at the places where rwsem_{set,clear}_owner() are called.
This also adds lockdep annotation of preemption disable in
rwsem_{set,clear}_owner() on Peter Z. suggestion.
Signed-off-by: Gokul krishna Krishnakumar <quic_gokukris@quicinc.com>
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/1662661467-24203-1-git-send-email-quic_mojha@quicinc.com
|
||
|
Marco Elver
|
01fe8a3f81 |
locking/percpu-rwsem: Add percpu_is_write_locked() and percpu_is_read_locked()
Implement simple accessors to probe percpu-rwsem's locked state: percpu_is_write_locked(), percpu_is_read_locked(). 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/20220829124719.675715-11-elver@google.com |
||
|
Namhyung Kim
|
501f7f69bc |
locking: Add __lockfunc to slow path functions
So that we can skip the functions in the perf lock contention and other places like /proc/PID/wchan. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20220810220346.1919485-1-namhyung@kernel.org |
||
|
Andi Kleen
|
9aeaf5bc4e |
locking/spinlocks: Mark spinlocks noinline when inline spinlocks are disabled
Otherwise LTO will inline them anyways and cause a large kernel text increase. Since the explicit intention here is to not inline them marking them noinline is good documentation even for the non-LTO case. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Martin Liska <mliska@suse.cz> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220719110548.1544-1-jslaby@suse.cz |
||
|
Linus Torvalds
|
7d9d077c78 |
RCU pull request for v5.20 (or whatever)
This pull request contains the following branches: doc.2022.06.21a: Documentation updates. fixes.2022.07.19a: Miscellaneous fixes. nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms. poll.2022.07.21a: Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods. rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead. torture.2022.06.21a: Torture-test updates. ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y. -----BEGIN PGP SIGNATURE----- iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmLgMcgTHHBhdWxtY2tA a2VybmVsLm9yZwAKCRCevxLzctn7jArXD/0fjbCwqpRjHVTzjMY8jN4zDkqZZD6m g8Fx27hZ4ToNFwRptyHwNezrNj14skjAJEXfdjaVw32W62ivXvf0HINvSzsTLCSq k2kWyBdXLc9CwY5p5W4smnpn5VoAScjg5PoPL59INoZ/Zziji323C7Zepl/1DYJt 0T6bPCQjo1ZQoDUCyVpSjDmAqxnderWG0MeJVt74GkLqmnYLANg0GH8c7mH4+9LL kVGlLp5nlPgNJ4FEoFdMwNU8T/ETmaVld/m2dkiawjkXjJzB2XKtBigU91DDmXz5 7DIdV4ABrxiy4kGNqtIe/jFgnKyVD7xiDpyfjd6KTeDr/rDS8u2ZH7+1iHsyz3g0 Np/tS3vcd0KR+gI/d0eXxPbgm5sKlCmKw/nU2eArpW/+4LmVXBUfHTG9Jg+LJmBc JrUh6aEdIZJZHgv/nOQBNig7GJW43IG50rjuJxAuzcxiZNEG5lUSS23ysaA9CPCL PxRWKSxIEfK3kdmvVO5IIbKTQmIBGWlcWMTcYictFSVfBgcCXpPAksGvqA5JiUkc egW+xLFo/7K+E158vSKsVqlWZcEeUbsNJ88QOlpqnRgH++I2Yv/LhK41XfJfpH+Y ALxVaDd+mAq6v+qSHNVq9wT3ozXIPy/zK1hDlMIqx40h2YvaEsH4je+521oSoN9r vX60+QNxvUBLwA== =vUNm -----END PGP SIGNATURE----- Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu Pull RCU updates from Paul McKenney: - Documentation updates - Miscellaneous fixes - Callback-offload updates, perhaps most notably a new RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be offloaded at boot time, regardless of kernel boot parameters. This is useful to battery-powered systems such as ChromeOS and Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot parameter prevents offloaded callbacks from interfering with real-time workloads and with energy-efficiency mechanisms - Polled grace-period updates, perhaps most notably making these APIs account for both normal and expedited grace periods - Tasks RCU updates, perhaps most notably reducing the CPU overhead of RCU tasks trace grace periods by more than a factor of two on a system with 15,000 tasks. The reduction is expected to increase with the number of tasks, so it seems reasonable to hypothesize that a system with 150,000 tasks might see a 20-fold reduction in CPU overhead - Torture-test updates - Updates that merge RCU's dyntick-idle tracking into context tracking, thus reducing the overhead of transitioning to kernel mode from either idle or nohz_full userspace execution for kernels that track context independently of RCU. This is expected to be helpful primarily for kernels built with CONFIG_NO_HZ_FULL=y * tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits) rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings rcu: Diagnose extended sync_rcu_do_polled_gp() loops rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings rcutorture: Test polled expedited grace-period primitives rcu: Add polled expedited grace-period primitives rcutorture: Verify that polled GP API sees synchronous grace periods rcu: Make Tiny RCU grace periods visible to polled APIs rcu: Make polled grace-period API account for expedited grace periods rcu: Switch polled grace-period APIs to ->gp_seq_polled rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty rcu/nocb: Add option to opt rcuo kthreads out of RT priority rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() rcu/nocb: Add an option to offload all CPUs on boot rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order rcu/nocb: Add/del rdp to iterate from rcuog itself rcu/tree: Add comment to describe GP-done condition in fqs loop rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs() rcu/kvfree: Remove useless monitor_todo flag rcu: Cleanup RCU urgency state for offline CPU ... |
||
|
Linus Torvalds
|
22a39c3d86 |
This was a fairly quiet cycle for the locking subsystem:
- lockdep: Fix a handful of the more complex lockdep_init_map_*() primitives
that can lose the lock_type & cause false reports. No such mishap was
observed in the wild.
- jump_label improvements: simplify the cross-arch support of
initial NOP patching by making it arch-specific code (used on MIPS only),
and remove the s390 initial NOP patching that was superfluous.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=4B89
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"This was a fairly quiet cycle for the locking subsystem:
- lockdep: Fix a handful of the more complex lockdep_init_map_*()
primitives that can lose the lock_type & cause false reports. No
such mishap was observed in the wild.
- jump_label improvements: simplify the cross-arch support of initial
NOP patching by making it arch-specific code (used on MIPS only),
and remove the s390 initial NOP patching that was superfluous"
* tag 'locking-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Fix lockdep_init_map_*() confusion
jump_label: make initial NOP patching the special case
jump_label: mips: move module NOP patching into arch code
jump_label: s390: avoid pointless initial NOP patching
|
||
|
Waiman Long
|
6eebd5fb20 |
locking/rwsem: Allow slowpath writer to ignore handoff bit if not set by first waiter
With commit |
||
|
Frederic Weisbecker
|
e67198cc05 |
context_tracking: Take idle eqs entrypoints over RCU
The RCU dynticks counter is going to be merged into the context tracking subsystem. Start with moving the idle extended quiescent states entrypoints to context tracking. For now those are dumb redirections to existing RCU calls. [ paulmck: Apply kernel test robot feedback. ] Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> |
||
|
Peter Zijlstra
|
eae6d58d67 |
locking/lockdep: Fix lockdep_init_map_*() confusion
Commit |
||
|
Sebastian Andrzej Siewior
|
4051a81774 |
locking/lockdep: Use sched_clock() for random numbers
Since the rewrote of prandom_u32(), in the commit mentioned below, the
function uses sleeping locks which extracing random numbers and filling
the batch.
This breaks lockdep on PREEMPT_RT because lock_pin_lock() disables
interrupts while calling __lock_pin_lock(). This can't be moved earlier
because the main user of the function (rq_pin_lock()) invokes that
function after disabling interrupts in order to acquire the lock.
The cookie does not require random numbers as its goal is to provide a
random value in order to notice unexpected "unlock + lock" sites.
Use sched_clock() to provide random numbers.
Fixes: a0103f4d86f88 ("random32: use real rng for non-deterministic randomness")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YoNn3pTkm5+QzE5k@linutronix.de
|
||
|
Linus Torvalds
|
44d35720c9 |
sysctl changes for v5.19-rc1
For two kernel releases now kernel/sysctl.c has been being cleaned up slowly, since the tables were grossly long, sprinkled with tons of #ifdefs and all this caused merge conflicts with one susbystem or another. This tree was put together to help try to avoid conflicts with these cleanups going on different trees at time. So nothing exciting on this pull request, just cleanups. I actually had this sysctl-next tree up since v5.18 but I missed sending a pull request for it on time during the last merge window. And so these changes have been being soaking up on sysctl-next and so linux-next for a while. The last change was merged May 4th. Most of the compile issues were reported by 0day and fixed. To help avoid a conflict with bpf folks at Daniel Borkmann's request I merged bpf-next/pr/bpf-sysctl into sysctl-next to get the effor which moves the BPF sysctls from kernel/sysctl.c to BPF core. Possible merge conflicts and known resolutions as per linux-next: bfp: https://lkml.kernel.org/r/20220414112812.652190b5@canb.auug.org.au rcu: https://lkml.kernel.org/r/20220420153746.4790d532@canb.auug.org.au powerpc: https://lkml.kernel.org/r/20220520154055.7f964b76@canb.auug.org.au -----BEGIN PGP SIGNATURE----- iQJGBAABCgAwFiEENnNq2KuOejlQLZofziMdCjCSiKcFAmKOq8ASHG1jZ3JvZkBr ZXJuZWwub3JnAAoJEM4jHQowkoinDAkQAJVo5YVM9f74UwYp4PQhTpjxJBCjRoZD z1u9bp5rMj2ujTC8Fr7VmzKaHrb8+r1C1WvCvZtIzemYNB4lZUrHpVDYfXuXiPRB ihPmEjhlPO5PFBx6cVCpI3cu9bEhG00rLc1QXnABx/pXwNPcOTJAGZJVamZvqubk chjgZrb7N+adHPfvS55v1+zpwdeKfpp5U3zuu5qlT/nn0GS0HCVzOj5fj4oC4wtJ IqfUubo+FX50Ga58yQABWNrjaPD9Crykz5ohVazy3ElQl0hJ4VsK65ct3blqc2vz 1Bb8kPpWuv6aZ5nr1lCVE8qvF4ZIL33ySvpg5BSdWLQEDrBbSpzvJe9Yn7wgR+eq y7fhpO24+zRM82EoDMEvyxX9u1n1RsvoXRtf3ds9BGf63MUxk8a1cgjlU6vuyO2U JhDmfM1xzdKvPoY4COOnHzcAiIqzItTqKd09N5y0cahmYstROU8lvp9huhTAHqk1 SjQMbLIZG7OnX8ZeQcR1EB8sq/IOPZT48ejj0iJmQ8FyMaep71MOQLYyLPAq4lgh JHXm8P6QdB57jfJbqAeNSyZoK0qdxOUR/83Zcah7Jjns6vkju1DNatEsaEEI2y2M 4n7/rkHeZ3TyFHBUX4e9FomKvGLsAalDBRiqsuxLSOPMU8rGrNLAslOAtKwvp90X 4ht3M2VP098l =btwh -----END PGP SIGNATURE----- Merge tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "For two kernel releases now kernel/sysctl.c has been being cleaned up slowly, since the tables were grossly long, sprinkled with tons of #ifdefs and all this caused merge conflicts with one susbystem or another. This tree was put together to help try to avoid conflicts with these cleanups going on different trees at time. So nothing exciting on this pull request, just cleanups. Thanks a lot to the Uniontech and Huawei folks for doing some of this nasty work" * tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (28 commits) sched: Fix build warning without CONFIG_SYSCTL reboot: Fix build warning without CONFIG_SYSCTL kernel/kexec_core: move kexec_core sysctls into its own file sysctl: minor cleanup in new_dir() ftrace: fix building with SYSCTL=y but DYNAMIC_FTRACE=n fs/proc: Introduce list_for_each_table_entry for proc sysctl mm: fix unused variable kernel warning when SYSCTL=n latencytop: move sysctl to its own file ftrace: fix building with SYSCTL=n but DYNAMIC_FTRACE=y ftrace: Fix build warning ftrace: move sysctl_ftrace_enabled to ftrace.c kernel/do_mount_initrd: move real_root_dev sysctls to its own file kernel/delayacct: move delayacct sysctls to its own file kernel/acct: move acct sysctls to its own file kernel/panic: move panic sysctls to its own file kernel/lockdep: move lockdep sysctls to its own file mm: move page-writeback sysctls to their own file mm: move oom_kill sysctls to their own file kernel/reboot: move reboot sysctls to its own file sched: Move energy_aware sysctls to topology.c ... |
||
|
Waiman Long
|
434e09e757 |
locking/qrwlock: Change "queue rwlock" to "queued rwlock"
Queued rwlock was originally named "queue rwlock" which wasn't quite grammatically correct. However there are still some "queue rwlock" references in the code. Change those to "queued rwlock" for consistency. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220510192134.434753-1-longman@redhat.com |
||
|
tangmeng
|
f79c9b8ae8 |
kernel/lockdep: move lockdep sysctls to its own file
kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. All filesystem syctls now get reviewed by fs folks. This commit follows the commit of fs, move the prove_locking and lock_stat sysctls to its own file, kernel/lockdep.c. Signed-off-by: tangmeng <tangmeng@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> |
||
|
Peter Zijlstra
|
dc1f7893a7 |
locking/mutex: Make contention tracepoints more consistent wrt adaptive spinning
Have the trace_contention_*() tracepoints consistently include adaptive spinning. In order to differentiate between the spinning and non-spinning states add LCB_F_MUTEX and combine with LCB_F_SPIN. The consequence is that a mutex contention can now triggler multiple _begin() tracepoints before triggering an _end(). Additionally, this fixes one path where mutex would trigger _end() without ever seeing a _begin(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
||
|
Namhyung Kim
|
ee042be16c |
locking: Apply contention tracepoints in the slow path
Adding the lock contention tracepoints in various lock function slow paths. Note that each arch can define spinlock differently, I only added it only to the generic qspinlock for now. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lkml.kernel.org/r/20220322185709.141236-3-namhyung@kernel.org |
||
|
Namhyung Kim
|
16edd9b511 |
locking: Add lock contention tracepoints
This adds two new lock contention tracepoints like below: * lock:contention_begin * lock:contention_end The lock:contention_begin takes a flags argument to classify locks. I found it useful to identify what kind of locks it's tracing like if it's spinning or sleeping, reader-writer lock, real-time, and per-cpu. Move tracepoint definitions into mutex.c so that we can use them without lockdep. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lkml.kernel.org/r/20220322185709.141236-2-namhyung@kernel.org |
||
|
Waiman Long
|
1ee326196c |
locking/rwsem: Always try to wake waiters in out_nolock path
For writers, the out_nolock path will always attempt to wake up waiters. This may not be really necessary if the waiter to be removed is not the first one. For readers, no attempt to wake up waiter is being made. However, if the HANDOFF bit is set and the reader to be removed is the first waiter, the waiter behind it will inherit the HANDOFF bit and for a write lock waiter waking it up will allow it to spin on the lock to acquire it faster. So it can be beneficial to do a wakeup in this case. Add a new rwsem_del_wake_waiter() helper function to do that consistently for both reader and writer out_nolock paths. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220322152059.2182333-4-longman@redhat.com |
||
|
Waiman Long
|
54c1ee4d61 |
locking/rwsem: Conditionally wake waiters in reader/writer slowpaths
In an analysis of a recent vmcore, a reader-owned rwsem was found with 385 readers but no writer in the wait queue. That is kind of unusual but it may be caused by some race conditions that we have not fully understood yet. In such a case, all the readers in the wait queue should join the other reader-owners and acquire the read lock. In rwsem_down_write_slowpath(), an incoming writer will try to wake up the front readers under such circumstance. That is not the case for rwsem_down_read_slowpath(), add a new helper function rwsem_cond_wake_waiter() to do wakeup and use it in both reader and writer slowpaths to have a consistent and correct behavior. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220322152059.2182333-3-longman@redhat.com |
||
|
Waiman Long
|
f9e21aa9e6 |
locking/rwsem: No need to check for handoff bit if wait queue empty
Since commit
|