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 <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
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 @@
}
/*
- * 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 @@
*/
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 @@
* 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 @@
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 @@
* 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 */
+}
/*