Commit c0bd1f65 authored by Jens Axboe's avatar Jens Axboe
Browse files

[PATCH] splice: only call wake_up_interruptible() when we really have to 



__wake_up_common() is pretty heavy in the kernel profiles, this brings
it down to a more acceptable level.

Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent 9aefe431

fs/splice.c

+12 −4
Original line number Diff line number Diff line
@@ -187,6 +187,8 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages, 
		}



		if (do_wakeup) {

			smp_mb();

			if (waitqueue_active(PIPE_WAIT(*inode)))

				wake_up_interruptible_sync(PIPE_WAIT(*inode));

			kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO,

				    POLL_IN);
@@ -201,6 +203,8 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages, 
	mutex_unlock(PIPE_MUTEX(*inode));



	if (do_wakeup) {

		smp_mb();

		if (waitqueue_active(PIPE_WAIT(*inode)))

			wake_up_interruptible(PIPE_WAIT(*inode));

		kill_fasync(PIPE_FASYNC_READERS(*inode), SIGIO, POLL_IN);

	}
@@ -600,6 +604,8 @@ static ssize_t move_from_pipe(struct inode *inode, struct file *out, 
		}



		if (do_wakeup) {

			smp_mb();

			if (waitqueue_active(PIPE_WAIT(*inode)))

				wake_up_interruptible_sync(PIPE_WAIT(*inode));

			kill_fasync(PIPE_FASYNC_WRITERS(*inode),SIGIO,POLL_OUT);

			do_wakeup = 0;
@@ -611,6 +617,8 @@ static ssize_t move_from_pipe(struct inode *inode, struct file *out, 
	mutex_unlock(PIPE_MUTEX(*inode));



	if (do_wakeup) {

		smp_mb();

		if (waitqueue_active(PIPE_WAIT(*inode)))

			wake_up_interruptible(PIPE_WAIT(*inode));

		kill_fasync(PIPE_FASYNC_WRITERS(*inode), SIGIO, POLL_OUT);

	}