From 85b6bc9db6d5ab6980b43c38b5cbd11d24414ce4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Aug 2015 14:55:18 -0700 Subject: blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup() Currently, both throttle and cfq policies implement their own root blkg (blkcg_gq) lookup fast path. This patch moves root blkg optimization from throtl_lookup_tg() to __blkg_lookup(). cfq-iosched currently doesn't use blkg_lookup() but will be converted and drop the optimization too. Signed-off-by: Tejun Heo Cc: Vivek Goyal Cc: Arianna Avanzini Signed-off-by: Jens Axboe --- include/linux/blk-cgroup.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index d5b54aa50582..0609bce69f68 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -249,6 +249,9 @@ static inline struct blkcg_gq *__blkg_lookup(struct blkcg *blkcg, { struct blkcg_gq *blkg; + if (blkcg == &blkcg_root) + return q->root_blkg; + blkg = rcu_dereference(blkcg->blkg_hint); if (blkg && blkg->q == q) return blkg; -- cgit v1.2.3