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authorTejun Heo <tj@kernel.org>2012-04-01 14:38:44 -0700
committerTejun Heo <tj@kernel.org>2012-04-01 14:38:44 -0700
commit8a3d26151f24e2a2ffa550890144c3d54d2edb15 (patch)
treeb99f5cf8db0abc02e39e5c5107f8d4342f81effa /block/blk-cgroup.c
parent155fead9b6347ead90e0b0396cb108a6ba6126c6 (diff)
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 <tj@kernel.org>
Diffstat (limited to 'block/blk-cgroup.c')
-rw-r--r--block/blk-cgroup.c98
1 files changed, 1 insertions, 97 deletions
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);