Oleg Nesterov 6fb614920b task_work_run: don't take ->pi_lock unconditionally ...

As Peter pointed out, task_work() can avoid ->pi_lock and cmpxchg()
if task->task_works == NULL && !PF_EXITING.

And in fact the only reason why task_work_run() needs ->pi_lock is
the possible race with task_work_cancel(), we can optimize this code
and make the locking more clear.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

2020-03-02 14:06:33 -07:00

3.4 KiB

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