From 4194b1eaf18ddc3eee9597e8800b6d2ffdfd3614 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 6 Apr 2009 14:48:05 +0200 Subject: jbd2: 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 Signed-off-by: Linus Torvalds --- fs/jbd2/commit.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 4ea72377c7a..073c8c3df7c 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -138,7 +138,7 @@ static int journal_submit_commit_record(journal_t *journal, set_buffer_ordered(bh); barrier_done = 1; } - ret = submit_bh(WRITE_SYNC, bh); + ret = submit_bh(WRITE_SYNC_PLUG, bh); if (barrier_done) clear_buffer_ordered(bh); @@ -159,7 +159,7 @@ static int journal_submit_commit_record(journal_t *journal, lock_buffer(bh); set_buffer_uptodate(bh); clear_buffer_dirty(bh); - ret = submit_bh(WRITE_SYNC, bh); + ret = submit_bh(WRITE_SYNC_PLUG, bh); } *cbh = bh; return ret; @@ -190,7 +190,7 @@ retry: set_buffer_uptodate(bh); bh->b_end_io = journal_end_buffer_io_sync; - ret = submit_bh(WRITE_SYNC, bh); + ret = submit_bh(WRITE_SYNC_PLUG, bh); if (ret) { unlock_buffer(bh); return ret; @@ -402,8 +402,13 @@ void jbd2_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; stats.u.run.rs_wait = commit_transaction->t_max_wait; stats.u.run.rs_locked = jiffies; stats.u.run.rs_running = jbd2_time_diff(commit_transaction->t_start, -- cgit v1.2.3