GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-23 15:11:16 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal

Browse source 
When a interruptible mutex locker is interrupted by a signal
without acquiring this lock and removed from the wait queue.
if the mutex isn't contended enough to have a waiter
put into the wait queue again, the setting of the WAITER
bit will force mutex locker to go into the slowpath to
acquire the lock every time, so if the wait queue is empty,
the WAITER bit need to be clear.

Fixes: 040a0a3710 ("mutex: Add support for wound/wait style locks")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210517034005.30828-1-qiang.zhang@windriver.com
This commit is contained in:
Zqiang 2021-05-17 11:40:05 +08:00 • committed by Peter Zijlstra
parent 89e70d5c58
commit 3a010c4932
4 changed files with 17 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

4
kernel/locking/mutex-debug.c
View file

@ -57,7 +57,7 @@ void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
task->blocked_on = waiter;
}
void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct task_struct *task)
{
DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
@ -65,7 +65,7 @@ void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
task->blocked_on = NULL;
list_del_init(&waiter->list);
INIT_LIST_HEAD(&waiter->list);
waiter->task = NULL;
}