linux/kernel/locking
Sebastian Andrzej Siewior c5bcab7558 locking/local_lock: Add local nested BH locking infrastructure.
Add local_lock_nested_bh() locking. It is based on local_lock_t and the
naming follows the preempt_disable_nested() example.

For !PREEMPT_RT + !LOCKDEP it is a per-CPU annotation for locking
assumptions based on local_bh_disable(). The macro is optimized away
during compilation.
For !PREEMPT_RT + LOCKDEP the local_lock_nested_bh() is reduced to
the usual lock-acquire plus lockdep_assert_in_softirq() - ensuring that
BH is disabled.

For PREEMPT_RT local_lock_nested_bh() acquires the specified per-CPU
lock. It does not disable CPU migration because it relies on
local_bh_disable() disabling CPU migration.
With LOCKDEP it performans the usual lockdep checks as with !PREEMPT_RT.
Due to include hell the softirq check has been moved spinlock.c.

The intention is to use this locking in places where locking of a per-CPU
variable relies on BH being disabled. Instead of treating disabled
bottom halves as a big per-CPU lock, PREEMPT_RT can use this to reduce
the locking scope to what actually needs protecting.
A side effect is that it also documents the protection scope of the
per-CPU variables.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20240620132727.660738-3-bigeasy@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-24 16:41:22 -07:00
..
irqflag-debug.c lockdep: Noinstr annotate warn_bogus_irq_restore() 2021-02-10 14:44:39 +01:00
lock_events_list.h locking/rwsem: Remove reader optimistic spinning 2020-12-09 17:08:48 +01:00
lock_events.c locking/debug: Fix debugfs API return value checks to use IS_ERR() 2023-10-03 10:11:25 +02:00
lock_events.h locking/qspinlock: Always evaluate lockevent* non-event parameter once 2024-03-21 20:45:17 +01:00
lockdep_internals.h locking/lockdep: Iterate lock_classes directly when reading lockdep files 2022-02-16 15:57:58 +01:00
lockdep_proc.c locking/lockdep: Fix string sizing bug that triggers a format-truncation compiler-warning 2023-10-12 20:37:59 +02:00
lockdep_states.h locking/lockdep: Rework FS_RECLAIM annotation 2017-08-10 12:29:03 +02:00
lockdep.c lockdep: Fix block chain corruption 2023-11-24 11:04:54 +01:00
locktorture.c locktorture: Increase Hamming distance between call_rcu_chain and rcu_call_chains 2023-11-23 11:58:18 +05:30
Makefile lockdep: allow instrumenting lockdep.c with KMSAN 2022-12-11 18:12:11 -08:00
mcs_spinlock.h locking: Fix typos in comments 2021-03-22 02:45:52 +01:00
mutex-debug.c locking/mutex: Introduce devm_mutex_init() 2024-04-11 17:34:41 +01:00
mutex.c locking/mutex: Document that mutex_unlock() is non-atomic 2023-12-01 11:27:43 +01:00
mutex.h locking/mutex: Move the 'struct mutex_waiter' definition from <linux/mutex.h> to the internal header 2021-08-17 18:24:31 +02:00
osq_lock.c locking/osq_lock: Clarify osq_wait_next() 2023-12-30 10:25:51 -08:00
percpu-rwsem.c locking/percpu-rwsem: Trigger contention tracepoints only if contended 2024-02-28 13:10:29 +01:00
qrwlock.c locking: Add __lockfunc to slow path functions 2022-08-19 19:47:51 +02:00
qspinlock_paravirt.h locking/pvqspinlock: Use try_cmpxchg() in qspinlock_paravirt.h 2024-04-12 11:42:39 +02:00
qspinlock_stat.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00
qspinlock.c locking/qspinlock: Use atomic_try_cmpxchg_relaxed() in xchg_tail() 2024-04-11 15:14:54 +02:00
rtmutex_api.c locking/rtmutex: Fix task->pi_waiters integrity 2023-07-17 13:59:10 +02:00
rtmutex_common.h locking/rtmutex: Fix task->pi_waiters integrity 2023-07-17 13:59:10 +02:00
rtmutex.c locking/rtmutex: Use try_cmpxchg_relaxed() in mark_rt_mutex_waiters() 2024-03-01 13:02:05 +01:00
rwbase_rt.c locking/rtmutex: Add a lockdep assert to catch potential nested blocking 2023-09-20 09:31:14 +02:00
rwsem.c locking/rwsem: Clarify that RWSEM_READER_OWNED is just a hint 2024-02-28 13:08:38 +01:00
semaphore.c locking: Add __sched to semaphore functions 2022-09-15 16:14:03 +02:00
spinlock_debug.c sched.h: move pid helpers to pid.h 2023-12-20 19:26:31 -05:00
spinlock_rt.c locking/rtmutex: Add a lockdep assert to catch potential nested blocking 2023-09-20 09:31:14 +02:00
spinlock.c locking/local_lock: Add local nested BH locking infrastructure. 2024-06-24 16:41:22 -07:00
test-ww_mutex.c locking/ww_mutex/test: Make sure we bail out instead of livelock 2023-09-22 09:43:41 +02:00
ww_mutex.h locking/rtmutex: Fix task->pi_waiters integrity 2023-07-17 13:59:10 +02:00
ww_rt_mutex.c locking/rtmutex: Avoid unconditional slowpath for DEBUG_RT_MUTEXES 2023-09-20 09:31:11 +02:00