user/sven/linux.git/kernel/locking, branch v6.9.11

locking/mutex: Introduce devm_mutex_init()

2024-07-11T10:50:55Z

[ Upstream commit 4cd47222e435dec8e3787614924174f53fcfb5ae ] Using of devm API leads to a certain order of releasing resources. So all dependent resources which are not devm-wrapped should be deleted with respect to devm-release order. Mutex is one of such objects that often is bound to other resources and has no own devm wrapping. Since mutex_destroy() actually does nothing in non-debug builds frequently calling mutex_destroy() is just ignored which is safe for now but wrong formally and can lead to a problem if mutex_destroy() will be extended so introduce devm_mutex_init(). Suggested-by: Christophe Leroy Signed-off-by: George Stark Reviewed-by: Christophe Leroy Reviewed-by: Andy Shevchenko Reviewed-by: Marek Behún Acked-by: Waiman Long Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com Signed-off-by: Lee Jones Stable-dep-of: efc347b9efee ("leds: mlxreg: Use devm_mutex_init() for mutex initialization") Signed-off-by: Sasha Levin

locking/rtmutex: Use try_cmpxchg_relaxed() in mark_rt_mutex_waiters()

2024-03-01T12:02:05Z

Use try_cmpxchg() instead of cmpxchg(*ptr, old, new) == old. The x86 CMPXCHG instruction returns success in the ZF flag, so this change saves a compare after CMPXCHG (and related move instruction in front of CMPXCHG). Also, try_cmpxchg() implicitly assigns old *ptr value to "old" when CMPXCHG fails. There is no need to re-read the value in the loop. Note that the value from *ptr should be read using READ_ONCE() to prevent the compiler from merging, refetching or reordering the read. No functional change intended. Signed-off-by: Uros Bizjak Signed-off-by: Ingo Molnar Cc: Peter Zijlstra Cc: Waiman Long Cc: Will Deacon Cc: Thomas Gleixner Cc: Linus Torvalds Cc: Paul E. McKenney Link: https://lore.kernel.org/r/20240124104953.612063-1-ubizjak@gmail.com

locking/percpu-rwsem: Trigger contention tracepoints only if contended

2024-02-28T12:10:29Z

We mistakenly always fire lock contention tracepoints in the writer path, while it should be conditional on the trylock result. Signed-off-by: Namhyung Kim Signed-off-by: Ingo Molnar Reviewed-by: Waiman Long Link: https://lore.kernel.org/r/20231108215322.2845536-1-namhyung@kernel.org

locking/rwsem: Clarify that RWSEM_READER_OWNED is just a hint

2024-02-28T12:08:38Z

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 Signed-off-by: Ingo Molnar Reviewed-by: Boqun Feng Link: https://lore.kernel.org/r/20240222150540.79981-4-longman@redhat.com

locking/qspinlock: Fix 'wait_early' set but not used warning

2024-02-28T12:08:37Z

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 Signed-off-by: Waiman Long Signed-off-by: Ingo Molnar Reviewed-by: Boqun Feng Cc: Linus Torvalds 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/

Merge tag 'rcu.release.v6.8' of https://github.com/neeraju/linux

2024-01-13T00:35:58Z

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

Merge tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs

2024-01-11T00:43:55Z

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 ...

Merge tag 'v6.7-rc8' into locking/core, to pick up dependent changes

2024-01-02T09:41:38Z

Pick up these commits from Linus's tree: b106bcf0f99a ("locking/osq_lock: Clarify osq_wait_next()") 563adbfc351b ("locking/osq_lock: Clarify osq_wait_next() calling convention") 7c2230982129 ("locking/osq_lock: Move the definition of optimistic_spin_node into osq_lock.c") Signed-off-by: Ingo Molnar

locking/osq_lock: Clarify osq_wait_next()

2023-12-30T18:25:51Z

Directly return NULL or 'next' instead of breaking out of the loop. Signed-off-by: David Laight [ Split original patch into two independent parts - Linus ] Link: https://lore.kernel.org/lkml/7c8828aec72e42eeb841ca0ee3397e9a@AcuMS.aculab.com/ Signed-off-by: Linus Torvalds

locking/osq_lock: Clarify osq_wait_next() calling convention

2023-12-30T18:25:51Z

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 [ Changed 'old' to 'old_cpu' by request from Waiman Long - Linus ] Signed-off-by: Linus Torvalds