From: Jens Axboe Date: Tue, 7 Apr 2009 09:38:31 +0000 (+0200) Subject: cfq-iosched: don't let idling interfere with plugging X-Git-Tag: v2.6.30-rc1~6^2~1 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b029195dda0129b427c6e579a3bb3ae752da3a93;p=pandora-kernel.git cfq-iosched: don't let idling interfere with plugging When CFQ is waiting for a new request from a process, currently it'll immediately restart queuing when it sees such a request. This doesn't work very well with streamed IO, since we then end up splitting IO that would otherwise have been merged nicely. For a simple dd test, this causes 10x as many requests to be issued as we should have. Normally this goes unnoticed due to the low overhead of requests at the device side, but some hardware is very sensitive to request sizes and there it can cause big slow downs. Signed-off-by: Jens Axboe --- Reading git-diff-tree failed