From 453eac8a9aa417878a38bdfbccafd5f7ce4e8e4e Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 11 Jan 2010 11:49:58 +0000 Subject: xfs: Don't wake the aild once per second Now that the AIL push algorithm is traversal safe, we don't need a watchdog function in the xfsaild to catch pushes that fail to make progress. Remove the watchdog timeout and make pushes purely driven by demand. This will remove the once-per-second wakeup that is seen when the filesystem is idle and make laptop power misers happy. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_trans_ail.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 2ffc570..063dfbd 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -237,14 +237,15 @@ out: } /* - * Function that does the work of pushing on the AIL + * xfsaild_push does the work of pushing on the AIL. Returning a timeout of + * zero indicates that the caller should sleep until woken. */ long xfsaild_push( struct xfs_ail *ailp, xfs_lsn_t *last_lsn) { - long tout = 1000; /* milliseconds */ + long tout = 0; xfs_lsn_t last_pushed_lsn = *last_lsn; xfs_lsn_t target = ailp->xa_target; xfs_lsn_t lsn; @@ -262,7 +263,7 @@ xfsaild_push( */ xfs_trans_ail_cursor_done(ailp, cur); spin_unlock(&ailp->xa_lock); - last_pushed_lsn = 0; + *last_lsn = 0; return tout; } @@ -279,7 +280,6 @@ xfsaild_push( * prevents use from spinning when we can't do anything or there is * lots of contention on the AIL lists. */ - tout = 10; lsn = lip->li_lsn; flush_log = stuck = count = 0; while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { @@ -376,14 +376,14 @@ xfsaild_push( if (!count) { /* We're past our target or empty, so idle */ - tout = 1000; + last_pushed_lsn = 0; } else if (XFS_LSN_CMP(lsn, target) >= 0) { /* * We reached the target so wait a bit longer for I/O to * complete and remove pushed items from the AIL before we * start the next scan from the start of the AIL. */ - tout += 20; + tout = 50; last_pushed_lsn = 0; } else if ((stuck * 100) / count > 90) { /* @@ -395,11 +395,14 @@ xfsaild_push( * Backoff a bit more to allow some I/O to complete before * continuing from where we were. */ - tout += 10; + tout = 20; + } else { + /* more to do, but wait a short while before continuing */ + tout = 10; } *last_lsn = last_pushed_lsn; return tout; -} /* xfsaild_push */ +} /* -- cgit v1.1 From a14a348bff2f99471a28e5928eb6801224c053d8 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 19 Jan 2010 09:56:46 +0000 Subject: xfs: cleanup up xfs_log_force calling conventions Remove the XFS_LOG_FORCE argument which was always set, and the XFS_LOG_URGE define, which was never used. Split xfs_log_force into a two helpers - xfs_log_force which forces the whole log, and xfs_log_force_lsn which forces up to the specified LSN. The underlying implementations already were entirely separate, as were the users. Also re-indent the new _xfs_log_force/_xfs_log_force which previously had a weird coding style. Signed-off-by: Christoph Hellwig Signed-off-by: Alex Elder --- fs/xfs/xfs_trans_ail.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 063dfbd..d7b1af8 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -371,7 +371,7 @@ xfsaild_push( * move forward in the AIL. */ XFS_STATS_INC(xs_push_ail_flush); - xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE); + xfs_log_force(mp, 0); } if (!count) { -- cgit v1.1 From d808f617ad00a413585b806de340feda5ad9a2da Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 2 Feb 2010 10:13:42 +1100 Subject: xfs: Don't issue buffer IO direct from AIL push V2 All buffers logged into the AIL are marked as delayed write. When the AIL needs to push the buffer out, it issues an async write of the buffer. This means that IO patterns are dependent on the order of buffers in the AIL. Instead of flushing the buffer, promote the buffer in the delayed write list so that the next time the xfsbufd is run the buffer will be flushed by the xfsbufd. Return the state to the xfsaild that the buffer was promoted so that the xfsaild knows that it needs to cause the xfsbufd to run to flush the buffers that were promoted. Using the xfsbufd for issuing the IO allows us to dispatch all buffer IO from the one queue. This means that we can make much more enlightened decisions on what order to flush buffers to disk as we don't have multiple places issuing IO. Optimisations to xfsbufd will be in a future patch. Version 2 - kill XFS_ITEM_FLUSHING as it is now unused. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_trans_ail.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'fs/xfs/xfs_trans_ail.c') diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index d7b1af8..e799824 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -253,6 +253,7 @@ xfsaild_push( int flush_log, count, stuck; xfs_mount_t *mp = ailp->xa_mount; struct xfs_ail_cursor *cur = &ailp->xa_cursors; + int push_xfsbufd = 0; spin_lock(&ailp->xa_lock); xfs_trans_ail_cursor_init(ailp, cur); @@ -308,6 +309,7 @@ xfsaild_push( XFS_STATS_INC(xs_push_ail_pushbuf); IOP_PUSHBUF(lip); last_pushed_lsn = lsn; + push_xfsbufd = 1; break; case XFS_ITEM_PINNED: @@ -322,12 +324,6 @@ xfsaild_push( stuck++; break; - case XFS_ITEM_FLUSHING: - XFS_STATS_INC(xs_push_ail_flushing); - last_pushed_lsn = lsn; - stuck++; - break; - default: ASSERT(0); break; @@ -374,6 +370,11 @@ xfsaild_push( xfs_log_force(mp, 0); } + if (push_xfsbufd) { + /* we've got delayed write buffers to flush */ + wake_up_process(mp->m_ddev_targp->bt_task); + } + if (!count) { /* We're past our target or empty, so idle */ last_pushed_lsn = 0; -- cgit v1.1