diff options
| author | Jens Axboe <jens.axboe@oracle.com> | 2010-05-17 12:51:03 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-07-05 11:10:45 -0700 |
| commit | 584516620656c12f751d9714240d3056bcf76fca (patch) | |
| tree | cb8253756ad473d962f27abb9c509448a99a5bf2 /fs/fs-writeback.c | |
| parent | 63592befd6212caabbe5f9517f64049d55ec67fb (diff) | |
writeback: disable periodic old data writeback for !dirty_writeback_centisecs
commit 69b62d01ec44fe0d505d89917392347732135a4d upstream.
Prior to 2.6.32, setting /proc/sys/vm/dirty_writeback_centisecs disabled
periodic dirty writeback from kupdate. This got broken and now causes
excessive sys CPU usage if set to zero, as we'll keep beating on
schedule().
Reported-by: Justin Maggard <jmaggard10@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index bff5f775e9bc..ef2acd24cc02 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -859,6 +859,12 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb) unsigned long expired; long nr_pages; + /* + * When set to zero, disable periodic writeback + */ + if (!dirty_writeback_interval) + return 0; + expired = wb->last_old_flush + msecs_to_jiffies(dirty_writeback_interval * 10); if (time_before(jiffies, expired)) @@ -954,8 +960,12 @@ int bdi_writeback_task(struct bdi_writeback *wb) break; } - wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10); - schedule_timeout_interruptible(wait_jiffies); + if (dirty_writeback_interval) { + wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10); + schedule_timeout_interruptible(wait_jiffies); + } else + schedule(); + try_to_freeze(); } |