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>
This commit is contained in:
Tejun Heo
parent
155fead9b6
commit
8a3d26151f
|
|
@ -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);
|
||||
|
|
|
|||
|
|
@ -64,14 +64,6 @@ struct blkg_rwstat {
|
|||
uint64_t cnt[BLKG_RWSTAT_NR];
|
||||
};
|
||||
|
||||
/* Per cpu blkio group stats */
|
||||
struct blkio_group_stats_cpu {
|
||||
/* total bytes transferred */
|
||||
struct blkg_rwstat service_bytes;
|
||||
/* total IOs serviced, post merge */
|
||||
struct blkg_rwstat serviced;
|
||||
};
|
||||
|
||||
struct blkio_group_conf {
|
||||
unsigned int weight;
|
||||
u64 iops[2];
|
||||
|
|
@ -86,9 +78,6 @@ struct blkg_policy_data {
|
|||
/* Configuration */
|
||||
struct blkio_group_conf conf;
|
||||
|
||||
/* Per cpu stats pointer */
|
||||
struct blkio_group_stats_cpu __percpu *stats_cpu;
|
||||
|
||||
/* pol->pdata_size bytes of private data used by policy impl */
|
||||
char pdata[] __aligned(__alignof__(unsigned long long));
|
||||
};
|
||||
|
|
@ -106,8 +95,6 @@ struct blkio_group {
|
|||
|
||||
struct blkg_policy_data *pd[BLKIO_NR_POLICIES];
|
||||
|
||||
/* List of blkg waiting for per cpu stats memory to be allocated */
|
||||
struct list_head alloc_node;
|
||||
struct rcu_head rcu_head;
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -40,6 +40,14 @@ struct throtl_rb_root {
|
|||
|
||||
#define rb_entry_tg(node) rb_entry((node), struct throtl_grp, rb_node)
|
||||
|
||||
/* Per-cpu group stats */
|
||||
struct tg_stats_cpu {
|
||||
/* total bytes transferred */
|
||||
struct blkg_rwstat service_bytes;
|
||||
/* total IOs serviced, post merge */
|
||||
struct blkg_rwstat serviced;
|
||||
};
|
||||
|
||||
struct throtl_grp {
|
||||
/* active throtl group service_tree member */
|
||||
struct rb_node rb_node;
|
||||
|
|
@ -76,6 +84,12 @@ struct throtl_grp {
|
|||
|
||||
/* Some throttle limits got updated for the group */
|
||||
int limits_changed;
|
||||
|
||||
/* Per cpu stats pointer */
|
||||
struct tg_stats_cpu __percpu *stats_cpu;
|
||||
|
||||
/* List of tgs waiting for per cpu stats memory to be allocated */
|
||||
struct list_head stats_alloc_node;
|
||||
};
|
||||
|
||||
struct throtl_data
|
||||
|
|
@ -100,6 +114,13 @@ struct throtl_data
|
|||
int limits_changed;
|
||||
};
|
||||
|
||||
/* list and work item to allocate percpu group stats */
|
||||
static DEFINE_SPINLOCK(tg_stats_alloc_lock);
|
||||
static LIST_HEAD(tg_stats_alloc_list);
|
||||
|
||||
static void tg_stats_alloc_fn(struct work_struct *);
|
||||
static DECLARE_DELAYED_WORK(tg_stats_alloc_work, tg_stats_alloc_fn);
|
||||
|
||||
static inline struct throtl_grp *blkg_to_tg(struct blkio_group *blkg)
|
||||
{
|
||||
return blkg_to_pdata(blkg, &blkio_policy_throtl);
|
||||
|
|
@ -142,6 +163,44 @@ static inline unsigned int total_nr_queued(struct throtl_data *td)
|
|||
return td->nr_queued[0] + td->nr_queued[1];
|
||||
}
|
||||
|
||||
/*
|
||||
* Worker for allocating per cpu stat for tgs. This is scheduled on the
|
||||
* system_nrt_wq once there are some groups on the alloc_list waiting for
|
||||
* allocation.
|
||||
*/
|
||||
static void tg_stats_alloc_fn(struct work_struct *work)
|
||||
{
|
||||
static struct tg_stats_cpu *stats_cpu; /* this fn is non-reentrant */
|
||||
struct delayed_work *dwork = to_delayed_work(work);
|
||||
bool empty = false;
|
||||
|
||||
alloc_stats:
|
||||
if (!stats_cpu) {
|
||||
stats_cpu = alloc_percpu(struct tg_stats_cpu);
|
||||
if (!stats_cpu) {
|
||||
/* allocation failed, try again after some time */
|
||||
queue_delayed_work(system_nrt_wq, dwork,
|
||||
msecs_to_jiffies(10));
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
spin_lock_irq(&tg_stats_alloc_lock);
|
||||
|
||||
if (!list_empty(&tg_stats_alloc_list)) {
|
||||
struct throtl_grp *tg = list_first_entry(&tg_stats_alloc_list,
|
||||
struct throtl_grp,
|
||||
stats_alloc_node);
|
||||
swap(tg->stats_cpu, stats_cpu);
|
||||
list_del_init(&tg->stats_alloc_node);
|
||||
}
|
||||
|
||||
empty = list_empty(&tg_stats_alloc_list);
|
||||
spin_unlock_irq(&tg_stats_alloc_lock);
|
||||
if (!empty)
|
||||
goto alloc_stats;
|
||||
}
|
||||
|
||||
static void throtl_init_blkio_group(struct blkio_group *blkg)
|
||||
{
|
||||
struct throtl_grp *tg = blkg_to_tg(blkg);
|
||||
|
|
@ -155,6 +214,43 @@ static void throtl_init_blkio_group(struct blkio_group *blkg)
|
|||
tg->bps[WRITE] = -1;
|
||||
tg->iops[READ] = -1;
|
||||
tg->iops[WRITE] = -1;
|
||||
|
||||
/*
|
||||
* Ugh... We need to perform per-cpu allocation for tg->stats_cpu
|
||||
* but percpu allocator can't be called from IO path. Queue tg on
|
||||
* tg_stats_alloc_list and allocate from work item.
|
||||
*/
|
||||
spin_lock(&tg_stats_alloc_lock);
|
||||
list_add(&tg->stats_alloc_node, &tg_stats_alloc_list);
|
||||
queue_delayed_work(system_nrt_wq, &tg_stats_alloc_work, 0);
|
||||
spin_unlock(&tg_stats_alloc_lock);
|
||||
}
|
||||
|
||||
static void throtl_exit_blkio_group(struct blkio_group *blkg)
|
||||
{
|
||||
struct throtl_grp *tg = blkg_to_tg(blkg);
|
||||
|
||||
spin_lock(&tg_stats_alloc_lock);
|
||||
list_del_init(&tg->stats_alloc_node);
|
||||
spin_unlock(&tg_stats_alloc_lock);
|
||||
|
||||
free_percpu(tg->stats_cpu);
|
||||
}
|
||||
|
||||
static void throtl_reset_group_stats(struct blkio_group *blkg)
|
||||
{
|
||||
struct throtl_grp *tg = blkg_to_tg(blkg);
|
||||
int cpu;
|
||||
|
||||
if (tg->stats_cpu == NULL)
|
||||
return;
|
||||
|
||||
for_each_possible_cpu(cpu) {
|
||||
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
|
||||
|
||||
blkg_rwstat_reset(&sc->service_bytes);
|
||||
blkg_rwstat_reset(&sc->serviced);
|
||||
}
|
||||
}
|
||||
|
||||
static struct
|
||||
|
|
@ -565,12 +661,12 @@ static bool tg_may_dispatch(struct throtl_data *td, struct throtl_grp *tg,
|
|||
static void throtl_update_dispatch_stats(struct blkio_group *blkg, u64 bytes,
|
||||
int rw)
|
||||
{
|
||||
struct blkg_policy_data *pd = blkg->pd[BLKIO_POLICY_THROTL];
|
||||
struct blkio_group_stats_cpu *stats_cpu;
|
||||
struct throtl_grp *tg = blkg_to_tg(blkg);
|
||||
struct tg_stats_cpu *stats_cpu;
|
||||
unsigned long flags;
|
||||
|
||||
/* If per cpu stats are not allocated yet, don't do any accounting. */
|
||||
if (pd->stats_cpu == NULL)
|
||||
if (tg->stats_cpu == NULL)
|
||||
return;
|
||||
|
||||
/*
|
||||
|
|
@ -580,7 +676,7 @@ static void throtl_update_dispatch_stats(struct blkio_group *blkg, u64 bytes,
|
|||
*/
|
||||
local_irq_save(flags);
|
||||
|
||||
stats_cpu = this_cpu_ptr(pd->stats_cpu);
|
||||
stats_cpu = this_cpu_ptr(tg->stats_cpu);
|
||||
|
||||
blkg_rwstat_add(&stats_cpu->serviced, rw, 1);
|
||||
blkg_rwstat_add(&stats_cpu->service_bytes, rw, bytes);
|
||||
|
|
@ -842,15 +938,15 @@ static void throtl_update_blkio_group_common(struct throtl_data *td,
|
|||
throtl_schedule_delayed_work(td, 0);
|
||||
}
|
||||
|
||||
static u64 blkg_prfill_cpu_rwstat(struct seq_file *sf,
|
||||
struct blkg_policy_data *pd, int off)
|
||||
static u64 tg_prfill_cpu_rwstat(struct seq_file *sf,
|
||||
struct blkg_policy_data *pd, int off)
|
||||
{
|
||||
struct throtl_grp *tg = (void *)pd->pdata;
|
||||
struct blkg_rwstat rwstat = { }, tmp;
|
||||
int i, cpu;
|
||||
|
||||
for_each_possible_cpu(cpu) {
|
||||
struct blkio_group_stats_cpu *sc =
|
||||
per_cpu_ptr(pd->stats_cpu, cpu);
|
||||
struct tg_stats_cpu *sc = per_cpu_ptr(tg->stats_cpu, cpu);
|
||||
|
||||
tmp = blkg_rwstat_read((void *)sc + off);
|
||||
for (i = 0; i < BLKG_RWSTAT_NR; i++)
|
||||
|
|
@ -861,12 +957,12 @@ static u64 blkg_prfill_cpu_rwstat(struct seq_file *sf,
|
|||
}
|
||||
|
||||
/* print per-cpu blkg_rwstat specified by BLKCG_STAT_PRIV() */
|
||||
static int blkcg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
|
||||
struct seq_file *sf)
|
||||
static int tg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
|
||||
struct seq_file *sf)
|
||||
{
|
||||
struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
|
||||
|
||||
blkcg_print_blkgs(sf, blkcg, blkg_prfill_cpu_rwstat,
|
||||
blkcg_print_blkgs(sf, blkcg, tg_prfill_cpu_rwstat,
|
||||
BLKCG_STAT_POL(cft->private),
|
||||
BLKCG_STAT_OFF(cft->private), true);
|
||||
return 0;
|
||||
|
|
@ -1012,14 +1108,14 @@ static struct cftype throtl_files[] = {
|
|||
{
|
||||
.name = "throttle.io_service_bytes",
|
||||
.private = BLKCG_STAT_PRIV(BLKIO_POLICY_THROTL,
|
||||
offsetof(struct blkio_group_stats_cpu, service_bytes)),
|
||||
.read_seq_string = blkcg_print_cpu_rwstat,
|
||||
offsetof(struct tg_stats_cpu, service_bytes)),
|
||||
.read_seq_string = tg_print_cpu_rwstat,
|
||||
},
|
||||
{
|
||||
.name = "throttle.io_serviced",
|
||||
.private = BLKCG_STAT_PRIV(BLKIO_POLICY_THROTL,
|
||||
offsetof(struct blkio_group_stats_cpu, serviced)),
|
||||
.read_seq_string = blkcg_print_cpu_rwstat,
|
||||
offsetof(struct tg_stats_cpu, serviced)),
|
||||
.read_seq_string = tg_print_cpu_rwstat,
|
||||
},
|
||||
{ } /* terminate */
|
||||
};
|
||||
|
|
@ -1034,6 +1130,8 @@ static void throtl_shutdown_wq(struct request_queue *q)
|
|||
static struct blkio_policy_type blkio_policy_throtl = {
|
||||
.ops = {
|
||||
.blkio_init_group_fn = throtl_init_blkio_group,
|
||||
.blkio_exit_group_fn = throtl_exit_blkio_group,
|
||||
.blkio_reset_group_stats_fn = throtl_reset_group_stats,
|
||||
},
|
||||
.plid = BLKIO_POLICY_THROTL,
|
||||
.pdata_size = sizeof(struct throtl_grp),
|
||||
|
|
|
|||
Reference in New Issue