When a user process enters TASK_INTERRUPTIBLE using the epoll_wait(2) system call and its variants, add the TASK_FREEZABLE flag to prevent the process from being prematurely awakened during suspend/resume, thus avoiding unnecessary wakeups and overhead. ep_poll is only used within the paths of epoll_wait-related system calls. In this path, after the process enters sleep, no kernel locks are held. Therefore, adding TASK_FREEZABLE is safe. Signed-off-by: Dai Junbing <daijunbing@xxxxxxxx> --- fs/eventpoll.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 0fbf5dfedb24..d52bd9838ef5 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -2094,7 +2094,7 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events, * the same lock on wakeup ep_poll_callback() side, so it * is safe to avoid an explicit barrier. */ - __set_current_state(TASK_INTERRUPTIBLE); + __set_current_state(TASK_INTERRUPTIBLE | TASK_FREEZABLE); /* * Do the final check under the lock. ep_start/done_scan() -- 2.25.1
