From: Jens Axboe Date: Thu, 30 Jul 2009 06:18:24 +0000 (+0200) Subject: block: improve queue_should_plug() by looking at IO depths X-Git-Tag: v2.6.32-rc1~688^2~20 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb1e75389bd06fd5987e9cda1b4e0305c782f854;p=pandora-kernel.git block: improve queue_should_plug() by looking at IO depths Instead of just checking whether this device uses block layer tagging, we can improve the detection by looking at the maximum queue depth it has reached. If that crosses 4, then deem it a queuing device. This is important on high IOPS devices, since plugging hurts the performance there (it can be as much as 10-15% of the sys time). Signed-off-by: Jens Axboe --- Reading git-diff-tree failed