cfq-iosched: reduce write depth only if sync was delayed
authorCorrado Zoccolo <czoccolo@gmail.com>
Sun, 6 Dec 2009 10:48:52 +0000 (11:48 +0100)
committerJens Axboe <axboe@carl.(none)>
Wed, 9 Dec 2009 11:32:55 +0000 (12:32 +0100)
commit573412b29586e58477adb70e022193a337763319
tree757ebcc4da3ba7b8d8beb8e8e0ff6a4fe4428f52
parent2b876f95d03e226394b5d360c86127cbefaf614b
cfq-iosched: reduce write depth only if sync was delayed

The introduction of ramp-up formula for async queue depths has
slowed down dirty page reclaim, by reducing async write performance.
This patch makes sure the formula kicks in only when sync request
was recently delayed.

Signed-off-by: Corrado Zoccolo <czoccolo@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block/cfq-iosched.c