From f4da80727cfbc3590d95ff17ef8db96e6f1483a4 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 8 Sep 2014 08:15:20 +0900 Subject: [PATCH] blkcg: remove blkcg->id blkcg->id is a unique id given to each blkcg; however, the cgroup_subsys_state which each blkcg embeds already has ->serial_nr which can be used for the same purpose. Drop blkcg->id and replace its uses with blkcg->css.serial_nr. Rename cfq_cgroup->blkcg_id to ->blkcg_serial_nr and @id in check_blkcg_changed() to @serial_nr for consistency. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/blk-cgroup.c | 2 -- block/blk-cgroup.h | 3 --- block/cfq-iosched.c | 10 +++++----- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index e17da947f6bd..0ac817b750db 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -822,7 +822,6 @@ static void blkcg_css_free(struct cgroup_subsys_state *css) static struct cgroup_subsys_state * blkcg_css_alloc(struct cgroup_subsys_state *parent_css) { - static atomic64_t id_seq = ATOMIC64_INIT(0); struct blkcg *blkcg; if (!parent_css) { @@ -836,7 +835,6 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) blkcg->cfq_weight = CFQ_WEIGHT_DEFAULT; blkcg->cfq_leaf_weight = CFQ_WEIGHT_DEFAULT; - blkcg->id = atomic64_inc_return(&id_seq); /* root is 0, start from 1 */ done: spin_lock_init(&blkcg->lock); INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_ATOMIC); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index d3fd7aa3d2a3..c567865b5f1d 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -50,9 +50,6 @@ struct blkcg { struct blkcg_gq *blkg_hint; struct hlist_head blkg_list; - /* for policies to test whether associated blkcg has changed */ - uint64_t id; - /* TODO: per-policy storage in blkcg */ unsigned int cfq_weight; /* belongs to cfq */ unsigned int cfq_leaf_weight; diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index cadc37841744..900f569afcc5 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -299,7 +299,7 @@ struct cfq_io_cq { struct cfq_ttime ttime; int ioprio; /* the current ioprio */ #ifdef CONFIG_CFQ_GROUP_IOSCHED - uint64_t blkcg_id; /* the current blkcg ID */ + uint64_t blkcg_serial_nr; /* the current blkcg serial */ #endif }; @@ -3534,17 +3534,17 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { struct cfq_data *cfqd = cic_to_cfqd(cic); struct cfq_queue *sync_cfqq; - uint64_t id; + uint64_t serial_nr; rcu_read_lock(); - id = bio_blkcg(bio)->id; + serial_nr = bio_blkcg(bio)->css.serial_nr; rcu_read_unlock(); /* * Check whether blkcg has changed. The condition may trigger * spuriously on a newly created cic but there's no harm. */ - if (unlikely(!cfqd) || likely(cic->blkcg_id == id)) + if (unlikely(!cfqd) || likely(cic->blkcg_serial_nr == serial_nr)) return; sync_cfqq = cic_to_cfqq(cic, 1); @@ -3558,7 +3558,7 @@ static void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) cfq_put_queue(sync_cfqq); } - cic->blkcg_id = id; + cic->blkcg_serial_nr = serial_nr; } #else static inline void check_blkcg_changed(struct cfq_io_cq *cic, struct bio *bio) { }