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> |
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| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||
| OWNERS | ||