diff options
| author | Tejun Heo <tj@kernel.org> | 2015-08-19 00:55:18 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-08-19 01:49:17 +0300 |
| commit | 85b6bc9db6d5ab6980b43c38b5cbd11d24414ce4 (patch) | |
| tree | 7389d8656738b72cc7c8c7569247db31800d9246 | |
| parent | 24f290466f79a6497f1654f64b9a841872cba3ca (diff) | |
| download | linux-85b6bc9db6d5ab6980b43c38b5cbd11d24414ce4.tar.xz | |
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 <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/blk-throttle.c | 7 | ||||
| -rw-r--r-- | include/linux/blk-cgroup.h | 3 |
2 files changed, 3 insertions, 7 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index c2c75477a6b2..1f63fc834dc3 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -452,13 +452,6 @@ static void throtl_pd_reset_stats(struct blkg_policy_data *pd) static struct throtl_grp *throtl_lookup_tg(struct throtl_data *td, struct blkcg *blkcg) { - /* - * This is the common case when there are no blkcgs. Avoid lookup - * in this case - */ - if (blkcg == &blkcg_root) - return td_root_tg(td); - return blkg_to_tg(blkg_lookup(blkcg, td->queue)); } 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; |