From: Christoph Hellwig Date: Thu, 17 Jun 2010 06:54:16 +0000 (+0200) Subject: block: BARRIER request should imply SYNC X-Git-Tag: v2.6.36-rc1~288^2~127 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=41f2df62894bfcd3bf868af916b32b90aa7168dc;p=pandora-kernel.git block: BARRIER request should imply SYNC A barrier request should by defintion have priority in get_request and let the queue be unplugged immediately as it's blocking all forward progress due to the queue draining. Most filesystems already get this implicitly by the way how submit_bh treats the buffer_ordered flag, and gfs2 sets it explicitly. But btrfs and XFS are still forgetting to set the flag, as is blkdev_issue_flush and some places in DM/MD. For XFS on metadata heavy workloads this gives a consistent speedup in the 2-3% range. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- Reading git-diff-tree failed