diff options
| author | Dave Chinner <david@fromorbit.com> | 2010-01-11 11:49:59 +0000 |
|---|---|---|
| committer | Alex Elder <aelder@sgi.com> | 2010-01-15 15:32:54 -0600 |
| commit | c9c129714e71c890bed1bd5b61697a896c3c2d54 (patch) | |
| tree | 8eff8e5ba534feb20dae7b143ea42bf0b0c24725 /fs/xfs/linux-2.6/xfs_buf.c | |
| parent | 453eac8a9aa417878a38bdfbccafd5f7ce4e8e4e (diff) | |
| download | lwn-c9c129714e71c890bed1bd5b61697a896c3c2d54.tar.gz lwn-c9c129714e71c890bed1bd5b61697a896c3c2d54.zip | |
xfs: Don't wake xfsbufd when idle
The xfsbufd wakes every xfsbufd_centisecs (once per second by
default) for each filesystem even when the filesystem is idle. If
the xfsbufd has nothing to do, put it into a long term sleep and
only wake it up when there is work pending (i.e. dirty buffers to
flush soon). This will 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>
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_buf.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index 77b8be81c769..18ae3ba8f78a 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -1595,6 +1595,11 @@ xfs_buf_delwri_queue( list_del(&bp->b_list); } + if (list_empty(dwq)) { + /* start xfsbufd as it is about to have something to do */ + wake_up_process(bp->b_target->bt_task); + } + bp->b_flags |= _XBF_DELWRI_Q; list_add_tail(&bp->b_list, dwq); bp->b_queuetime = jiffies; @@ -1644,6 +1649,8 @@ xfsbufd_wakeup( list_for_each_entry(btp, &xfs_buftarg_list, bt_list) { if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags)) continue; + if (list_empty(&btp->bt_delwrite_queue)) + continue; set_bit(XBT_FORCE_FLUSH, &btp->bt_flags); wake_up_process(btp->bt_task); } @@ -1708,6 +1715,9 @@ xfsbufd( set_freezable(); do { + long age = xfs_buf_age_centisecs * msecs_to_jiffies(10); + long tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10); + if (unlikely(freezing(current))) { set_bit(XBT_FORCE_SLEEP, &target->bt_flags); refrigerator(); @@ -1715,12 +1725,12 @@ xfsbufd( clear_bit(XBT_FORCE_SLEEP, &target->bt_flags); } - schedule_timeout_interruptible( - xfs_buf_timer_centisecs * msecs_to_jiffies(10)); - - xfs_buf_delwri_split(target, &tmp, - xfs_buf_age_centisecs * msecs_to_jiffies(10)); + /* sleep for a long time if there is nothing to do. */ + if (list_empty(&target->bt_delwrite_queue)) + tout = MAX_SCHEDULE_TIMEOUT; + schedule_timeout_interruptible(tout); + xfs_buf_delwri_split(target, &tmp, age); count = 0; while (!list_empty(&tmp)) { bp = list_entry(tmp.next, xfs_buf_t, b_list); |