57750518de
With hooks below, we can mark a lock-owned thread with an identifiable flag, which can protect it from being preempted by some other unimportant threads, and then waiter will be wakeup more quickly. https://android-review.googlesource.com/c/kernel/common/+/2183353 but now we find an issue like this one: static inline void __up_write(struct rw_semaphore *sem) { ... // Step 1. we clear flag. trace_android_vh_record_rwsem_lock_starttime(current, 0); // Step 2. owner may be preempted by unimportant threads. rwsem_clear_owner(sem); ... // Step 3. wake up waiter, but it's too later. if (unlikely(tmp & RWSEM_FLAG_WAITERS)) rwsem_wake(sem); } This patch will clear protect-flag after waking up waiters. Bug: 286024926 Change-Id: I71f8b6a7d8a01336fd36b8267c2cb5edab65bd11 Signed-off-by: xieliujie <xieliujie@oppo.com> |
||
|---|---|---|
| .. | ||
| irqflag-debug.c | ||
| lock_events.c | ||
| lock_events.h | ||
| lock_events_list.h | ||
| lockdep.c | ||
| lockdep_internals.h | ||
| lockdep_proc.c | ||
| lockdep_states.h | ||
| locktorture.c | ||
| Makefile | ||
| mcs_spinlock.h | ||
| mutex-debug.c | ||
| mutex.c | ||
| mutex.h | ||
| osq_lock.c | ||
| percpu-rwsem.c | ||
| qrwlock.c | ||
| qspinlock.c | ||
| qspinlock_paravirt.h | ||
| qspinlock_stat.h | ||
| rtmutex.c | ||
| rtmutex_api.c | ||
| rtmutex_common.h | ||
| rwbase_rt.c | ||
| rwsem.c | ||
| semaphore.c | ||
| spinlock.c | ||
| spinlock_debug.c | ||
| spinlock_rt.c | ||
| test-ww_mutex.c | ||
| ww_mutex.h | ||
| ww_rt_mutex.c | ||