[PATCH] cfq-iosched: merging problem
authorJens Axboe <jens.axboe@oracle.com>
Tue, 2 Jan 2007 17:32:11 +0000 (18:32 +0100)
committerLinus Torvalds <torvalds@woody.osdl.org>
Tue, 2 Jan 2007 17:46:16 +0000 (09:46 -0800)
commitec8acb6904fabb8e741f741ec99bb1c18f2b3dee
tree9d4da59b2ccc4b1424b90497c7b26778c272ca5a
parentdc3c3377f03634d351fafdfe35b237b283586c04
[PATCH] cfq-iosched: merging problem

Two issues:

- The final return 1 should be a return 0, otherwise comparing cfqq is
  a noop.

- bio_sync() only checks the sync flag, while rq_is_sync() checks both
  for READ and sync. The latter is what we want. Expand the bio check
  to include reads, and relax the restriction to allow merging of async
  io into sync requests.

In the future we want to clean up the SYNC logic, right now it means
both sync request (such as READ and O_DIRECT WRITE) and unplug-on-issue.
Leave that for later.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
block/cfq-iosched.c