jbd: use WRITE_SYNC_PLUG instead of WRITE_SYNC

When you are going to be submitting several sync writes, we want to
give the IO scheduler a chance to merge some of them. Instead of
using the implicitly unplugging WRITE_SYNC variant, use WRITE_SYNC_PLUG
and rely on sync_buffer() doing the unplug when someone does a
wait_on_buffer()/lock_buffer().

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jens Axboe 2009-04-06 14:48:04 +02:00 committed by Linus Torvalds
parent 9cf6b720f8
commit 6c4bac6b33

View file

@ -351,8 +351,13 @@ void journal_commit_transaction(journal_t *journal)
spin_lock(&journal->j_state_lock);
commit_transaction->t_state = T_LOCKED;
/*
* Use plugged writes here, since we want to submit several before
* we unplug the device. We don't do explicit unplugging in here,
* instead we rely on sync_buffer() doing the unplug for us.
*/
if (commit_transaction->t_synchronous_commit)
write_op = WRITE_SYNC;
write_op = WRITE_SYNC_PLUG;
spin_lock(&commit_transaction->t_handle_lock);
while (commit_transaction->t_updates) {
DEFINE_WAIT(wait);