From: Vivek Goyal Date: Thu, 19 May 2011 19:38:31 +0000 (-0400) Subject: blk-throttle: Make no throttling rule group processing lockless X-Git-Tag: v3.0-rc1~163^2~12 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=af75cd3c67845ebe31d2df9a780889a5ebecef11;p=pandora-kernel.git blk-throttle: Make no throttling rule group processing lockless Currently we take a queue lock on each bio to check if there are any throttling rules associated with the group and also update the stats. Now access the group under rcu and update the stats without taking the queue lock. Queue lock is taken only if there are throttling rules associated with the group. So the common case of root group when there are no rules, save unnecessary pounding of request queue lock. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe --- Reading git-diff-tree failed