Messages in this thread Patch in this message | | | Date | Thu, 1 Jun 2023 05:58:06 +0000 | Subject | [PATCH v4 03/13] locking/mutex: make mutex::wait_lock irq safe | From | John Stultz <> |
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From: Juri Lelli <juri.lelli@redhat.com>
mutex::wait_lock might be nested under rq->lock.
Make it irq safe then.
Cc: Joel Fernandes <joelaf@google.com> Cc: Qais Yousef <qyousef@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Zimuzo Ezeozue <zezeozue@google.com> Cc: Youssef Esmat <youssefesmat@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: kernel-team@android.com Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> [rebase & fix {un,}lock_wait_lock helpers in ww_mutex.h] Signed-off-by: Connor O'Brien <connoro@google.com> Signed-off-by: John Stultz <jstultz@google.com> --- v3: * Re-added this patch after it was dropped in v2 which caused lockdep warnings to trip. --- kernel/locking/mutex.c | 18 ++++++++++-------- kernel/locking/ww_mutex.h | 22 ++++++++++++---------- 2 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index 1582756914df..a528e7f42caa 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -572,6 +572,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas { struct mutex_waiter waiter; struct ww_mutex *ww; + unsigned long flags; int ret; if (!use_ww_ctx) @@ -614,7 +615,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas return 0; } - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); /* * After waiting to acquire the wait_lock, try again. */ @@ -675,7 +676,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas goto err; } - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); if (ww_ctx) ww_ctx_wake(ww_ctx); schedule_preempt_disabled(); @@ -698,9 +699,9 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas trace_contention_begin(lock, LCB_F_MUTEX); } - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); } - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); acquired: __set_current_state(TASK_RUNNING); @@ -726,7 +727,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas if (ww_ctx) ww_mutex_lock_acquired(ww, ww_ctx); - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); if (ww_ctx) ww_ctx_wake(ww_ctx); preempt_enable(); @@ -737,7 +738,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas __mutex_remove_waiter(lock, &waiter); err_early_kill: trace_contention_end(lock, ret); - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); debug_mutex_free_waiter(&waiter); mutex_release(&lock->dep_map, ip); if (ww_ctx) @@ -909,6 +910,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne struct task_struct *next = NULL; DEFINE_WAKE_Q(wake_q); unsigned long owner; + unsigned long flags; mutex_release(&lock->dep_map, ip); @@ -935,7 +937,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne } } - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, flags); debug_mutex_unlock(lock); if (!list_empty(&lock->wait_list)) { /* get the first entry from the wait-list: */ @@ -953,7 +955,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne __mutex_handoff(lock, next); preempt_disable(); - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); wake_up_q(&wake_q); preempt_enable(); diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h index e49ea5336473..984a4e0bff36 100644 --- a/kernel/locking/ww_mutex.h +++ b/kernel/locking/ww_mutex.h @@ -70,14 +70,14 @@ __ww_mutex_has_waiters(struct mutex *lock) return atomic_long_read(&lock->owner) & MUTEX_FLAG_WAITERS; } -static inline void lock_wait_lock(struct mutex *lock) +static inline void lock_wait_lock(struct mutex *lock, unsigned long *flags) { - raw_spin_lock(&lock->wait_lock); + raw_spin_lock_irqsave(&lock->wait_lock, *flags); } -static inline void unlock_wait_lock(struct mutex *lock) +static inline void unlock_wait_lock(struct mutex *lock, unsigned long flags) { - raw_spin_unlock(&lock->wait_lock); + raw_spin_unlock_irqrestore(&lock->wait_lock, flags); } static inline void lockdep_assert_wait_lock_held(struct mutex *lock) @@ -144,14 +144,14 @@ __ww_mutex_has_waiters(struct rt_mutex *lock) return rt_mutex_has_waiters(&lock->rtmutex); } -static inline void lock_wait_lock(struct rt_mutex *lock) +static inline void lock_wait_lock(struct rt_mutex *lock, unsigned long *flags) { - raw_spin_lock(&lock->rtmutex.wait_lock); + raw_spin_lock_irqsave(&lock->rtmutex.wait_lock, *flags); } -static inline void unlock_wait_lock(struct rt_mutex *lock) +static inline void unlock_wait_lock(struct rt_mutex *lock, flags) { - raw_spin_unlock(&lock->rtmutex.wait_lock); + raw_spin_unlock_irqrestore(&lock->rtmutex.wait_lock, flags); } static inline void lockdep_assert_wait_lock_held(struct rt_mutex *lock) @@ -383,6 +383,8 @@ __ww_mutex_check_waiters(struct MUTEX *lock, struct ww_acquire_ctx *ww_ctx) static __always_inline void ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) { + unsigned long flags; + ww_mutex_lock_acquired(lock, ctx); /* @@ -410,9 +412,9 @@ ww_mutex_set_context_fastpath(struct ww_mutex *lock, struct ww_acquire_ctx *ctx) * Uh oh, we raced in fastpath, check if any of the waiters need to * die or wound us. */ - lock_wait_lock(&lock->base); + lock_wait_lock(&lock->base, &flags); __ww_mutex_check_waiters(&lock->base, ctx); - unlock_wait_lock(&lock->base); + unlock_wait_lock(&lock->base, flags); } static __always_inline int -- 2.41.0.rc0.172.g3f132b7071-goog
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