From 8a3d26151f24e2a2ffa550890144c3d54d2edb15 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sun, 1 Apr 2012 14:38:44 -0700 Subject: blkcg: move blkio_group_stats_cpu and friends to blk-throttle.c blkio_group_stats_cpu is used only by blk-throtl and has no reason to be defined in blkcg core. * Move blkio_group_stats_cpu to blk-throttle.c and rename it to tg_stats_cpu. * blkg_policy_data->stats_cpu is replaced with throtl_grp->stats_cpu. prfill functions updated accordingly. * All related macros / functions are renamed so that they have tg_ prefix and the unnecessary @pol arguments are dropped. * Per-cpu stats allocation code is also moved from blk-cgroup.c to blk-throttle.c and gets simplified to only deal with BLKIO_POLICY_THROTL. percpu stat free is performed by the exit method throtl_exit_blkio_group(). * throtl_reset_group_stats() implemented for blkio_reset_group_stats_fn method so that tg->stats_cpu can be reset. Signed-off-by: Tejun Heo --- block/blk-cgroup.c | 98 +----------------------------------------------------- 1 file changed, 1 insertion(+), 97 deletions(-) (limited to 'block/blk-cgroup.c') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index cfdda44f4a0b..16f6ee65a593 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -30,13 +30,6 @@ static LIST_HEAD(blkio_list); static DEFINE_MUTEX(all_q_mutex); static LIST_HEAD(all_q_list); -/* List of groups pending per cpu stats allocation */ -static DEFINE_SPINLOCK(alloc_list_lock); -static LIST_HEAD(alloc_list); - -static void blkio_stat_alloc_fn(struct work_struct *); -static DECLARE_DELAYED_WORK(blkio_stat_alloc_work, blkio_stat_alloc_fn); - struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT }; EXPORT_SYMBOL_GPL(blkio_root_cgroup); @@ -63,60 +56,6 @@ struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio) } EXPORT_SYMBOL_GPL(bio_blkio_cgroup); -/* - * Worker for allocating per cpu stat for blk groups. This is scheduled on - * the system_nrt_wq once there are some groups on the alloc_list waiting - * for allocation. - */ -static void blkio_stat_alloc_fn(struct work_struct *work) -{ - static void *pcpu_stats[BLKIO_NR_POLICIES]; - struct delayed_work *dwork = to_delayed_work(work); - struct blkio_group *blkg; - int i; - bool empty = false; - -alloc_stats: - for (i = 0; i < BLKIO_NR_POLICIES; i++) { - if (pcpu_stats[i] != NULL) - continue; - - pcpu_stats[i] = alloc_percpu(struct blkio_group_stats_cpu); - - /* Allocation failed. Try again after some time. */ - if (pcpu_stats[i] == NULL) { - queue_delayed_work(system_nrt_wq, dwork, - msecs_to_jiffies(10)); - return; - } - } - - spin_lock_irq(&blkio_list_lock); - spin_lock(&alloc_list_lock); - - /* cgroup got deleted or queue exited. */ - if (!list_empty(&alloc_list)) { - blkg = list_first_entry(&alloc_list, struct blkio_group, - alloc_node); - for (i = 0; i < BLKIO_NR_POLICIES; i++) { - struct blkg_policy_data *pd = blkg->pd[i]; - - if (blkio_policy[i] && pd && !pd->stats_cpu) - swap(pd->stats_cpu, pcpu_stats[i]); - } - - list_del_init(&blkg->alloc_node); - } - - empty = list_empty(&alloc_list); - - spin_unlock(&alloc_list_lock); - spin_unlock_irq(&blkio_list_lock); - - if (!empty) - goto alloc_stats; -} - /** * blkg_free - free a blkg * @blkg: blkg to free @@ -140,7 +79,6 @@ static void blkg_free(struct blkio_group *blkg) if (pol && pol->ops.blkio_exit_group_fn) pol->ops.blkio_exit_group_fn(blkg); - free_percpu(pd->stats_cpu); kfree(pd); } @@ -167,7 +105,6 @@ static struct blkio_group *blkg_alloc(struct blkio_cgroup *blkcg, blkg->q = q; INIT_LIST_HEAD(&blkg->q_node); - INIT_LIST_HEAD(&blkg->alloc_node); blkg->blkcg = blkcg; blkg->refcnt = 1; cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); @@ -245,12 +182,6 @@ struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); list_add(&blkg->q_node, &q->blkg_list); spin_unlock(&blkcg->lock); - - spin_lock(&alloc_list_lock); - list_add(&blkg->alloc_node, &alloc_list); - /* Queue per cpu stat allocation from worker thread. */ - queue_delayed_work(system_nrt_wq, &blkio_stat_alloc_work, 0); - spin_unlock(&alloc_list_lock); out: return blkg; } @@ -284,10 +215,6 @@ static void blkg_destroy(struct blkio_group *blkg) list_del_init(&blkg->q_node); hlist_del_init_rcu(&blkg->blkcg_node); - spin_lock(&alloc_list_lock); - list_del_init(&blkg->alloc_node); - spin_unlock(&alloc_list_lock); - /* * Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. @@ -319,9 +246,6 @@ void update_root_blkg_pd(struct request_queue *q, enum blkio_policy_id plid) pd = kzalloc(sizeof(*pd) + pol->pdata_size, GFP_KERNEL); WARN_ON_ONCE(!pd); - pd->stats_cpu = alloc_percpu(struct blkio_group_stats_cpu); - WARN_ON_ONCE(!pd->stats_cpu); - blkg->pd[plid] = pd; pd->blkg = blkg; pol->ops.blkio_init_group_fn(blkg); @@ -381,23 +305,6 @@ void __blkg_release(struct blkio_group *blkg) } EXPORT_SYMBOL_GPL(__blkg_release); -static void blkio_reset_stats_cpu(struct blkio_group *blkg, int plid) -{ - struct blkg_policy_data *pd = blkg->pd[plid]; - int cpu; - - if (pd->stats_cpu == NULL) - return; - - for_each_possible_cpu(cpu) { - struct blkio_group_stats_cpu *sc = - per_cpu_ptr(pd->stats_cpu, cpu); - - blkg_rwstat_reset(&sc->service_bytes); - blkg_rwstat_reset(&sc->serviced); - } -} - static int blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) { @@ -416,12 +323,9 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { struct blkio_policy_type *pol; - list_for_each_entry(pol, &blkio_list, list) { - blkio_reset_stats_cpu(blkg, pol->plid); - + list_for_each_entry(pol, &blkio_list, list) if (pol->ops.blkio_reset_group_stats_fn) pol->ops.blkio_reset_group_stats_fn(blkg); - } } spin_unlock_irq(&blkcg->lock); -- cgit