Skip to content

Commit

Permalink
blk-cgroup: move struct blkg_stat to bfq
Browse files Browse the repository at this point in the history 
This structure and assorted infrastructure is only used by the bfq I/O
scheduler.  Move it there instead of bloating the common code.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
  • Loading branch information
Christoph Hellwig authored and Jens Axboe committed Jun 20, 2019
1 parent 7af6fd9 commit c0ce79d
Show file tree
Hide file tree
Showing 4 changed files with 167 additions and 171 deletions.
192 changes: 155 additions & 37 deletions block/bfq-cgroup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,124 @@

#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)

static int bfq_stat_init(struct bfq_stat *stat, gfp_t gfp)
{
int ret;

ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
if (ret)
return ret;

atomic64_set(&stat->aux_cnt, 0);
return 0;
}

static void bfq_stat_exit(struct bfq_stat *stat)
{
percpu_counter_destroy(&stat->cpu_cnt);
}

/**
* bfq_stat_add - add a value to a bfq_stat
* @stat: target bfq_stat
* @val: value to add
*
* Add @val to @stat. The caller must ensure that IRQ on the same CPU
* don't re-enter this function for the same counter.
*/
static inline void bfq_stat_add(struct bfq_stat *stat, uint64_t val)
{
percpu_counter_add_batch(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH);
}

/**
* bfq_stat_read - read the current value of a bfq_stat
* @stat: bfq_stat to read
*/
static inline uint64_t bfq_stat_read(struct bfq_stat *stat)
{
return percpu_counter_sum_positive(&stat->cpu_cnt);
}

/**
* bfq_stat_reset - reset a bfq_stat
* @stat: bfq_stat to reset
*/
static inline void bfq_stat_reset(struct bfq_stat *stat)
{
percpu_counter_set(&stat->cpu_cnt, 0);
atomic64_set(&stat->aux_cnt, 0);
}

/**
* bfq_stat_add_aux - add a bfq_stat into another's aux count
* @to: the destination bfq_stat
* @from: the source
*
* Add @from's count including the aux one to @to's aux count.
*/
static inline void bfq_stat_add_aux(struct bfq_stat *to,
struct bfq_stat *from)
{
atomic64_add(bfq_stat_read(from) + atomic64_read(&from->aux_cnt),
&to->aux_cnt);
}

/**
* bfq_stat_recursive_sum - collect hierarchical bfq_stat
* @blkg: blkg of interest
* @pol: blkcg_policy which contains the bfq_stat
* @off: offset to the bfq_stat in blkg_policy_data or @blkg
*
* Collect the bfq_stat specified by @blkg, @pol and @off and all its
* online descendants and their aux counts. The caller must be holding the
* queue lock for online tests.
*
* If @pol is NULL, bfq_stat is at @off bytes into @blkg; otherwise, it is
* at @off bytes into @blkg's blkg_policy_data of the policy.
*/
static u64 bfq_stat_recursive_sum(struct blkcg_gq *blkg,
struct blkcg_policy *pol, int off)
{
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
u64 sum = 0;

lockdep_assert_held(&blkg->q->queue_lock);

rcu_read_lock();
blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
struct bfq_stat *stat;

if (!pos_blkg->online)
continue;

if (pol)
stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
else
stat = (void *)blkg + off;

sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt);
}
rcu_read_unlock();

return sum;
}

/**
* blkg_prfill_stat - prfill callback for bfq_stat
* @sf: seq_file to print to
* @pd: policy private data of interest
* @off: offset to the bfq_stat in @pd
*
* prfill callback for printing a bfq_stat.
*/
static u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
return __blkg_prfill_u64(sf, pd, bfq_stat_read((void *)pd + off));
}

/* bfqg stats flags */
enum bfqg_stats_flags {
BFQG_stats_waiting = 0,
Expand Down Expand Up @@ -53,7 +171,7 @@ static void bfqg_stats_update_group_wait_time(struct bfqg_stats *stats)

now = ktime_get_ns();
if (now > stats->start_group_wait_time)
blkg_stat_add(&stats->group_wait_time,
bfq_stat_add(&stats->group_wait_time,
now - stats->start_group_wait_time);
bfqg_stats_clear_waiting(stats);
}
Expand Down Expand Up @@ -82,14 +200,14 @@ static void bfqg_stats_end_empty_time(struct bfqg_stats *stats)

now = ktime_get_ns();
if (now > stats->start_empty_time)
blkg_stat_add(&stats->empty_time,
bfq_stat_add(&stats->empty_time,
now - stats->start_empty_time);
bfqg_stats_clear_empty(stats);
}

void bfqg_stats_update_dequeue(struct bfq_group *bfqg)
{
blkg_stat_add(&bfqg->stats.dequeue, 1);
bfq_stat_add(&bfqg->stats.dequeue, 1);
}

void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg)
Expand Down Expand Up @@ -119,7 +237,7 @@ void bfqg_stats_update_idle_time(struct bfq_group *bfqg)
u64 now = ktime_get_ns();

if (now > stats->start_idle_time)
blkg_stat_add(&stats->idle_time,
bfq_stat_add(&stats->idle_time,
now - stats->start_idle_time);
bfqg_stats_clear_idling(stats);
}
Expand All @@ -137,9 +255,9 @@ void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg)
{
struct bfqg_stats *stats = &bfqg->stats;

blkg_stat_add(&stats->avg_queue_size_sum,
bfq_stat_add(&stats->avg_queue_size_sum,
blkg_rwstat_total(&stats->queued));
blkg_stat_add(&stats->avg_queue_size_samples, 1);
bfq_stat_add(&stats->avg_queue_size_samples, 1);
bfqg_stats_update_group_wait_time(stats);
}

Expand Down Expand Up @@ -279,13 +397,13 @@ static void bfqg_stats_reset(struct bfqg_stats *stats)
blkg_rwstat_reset(&stats->merged);
blkg_rwstat_reset(&stats->service_time);
blkg_rwstat_reset(&stats->wait_time);
blkg_stat_reset(&stats->time);
blkg_stat_reset(&stats->avg_queue_size_sum);
blkg_stat_reset(&stats->avg_queue_size_samples);
blkg_stat_reset(&stats->dequeue);
blkg_stat_reset(&stats->group_wait_time);
blkg_stat_reset(&stats->idle_time);
blkg_stat_reset(&stats->empty_time);
bfq_stat_reset(&stats->time);
bfq_stat_reset(&stats->avg_queue_size_sum);
bfq_stat_reset(&stats->avg_queue_size_samples);
bfq_stat_reset(&stats->dequeue);
bfq_stat_reset(&stats->group_wait_time);
bfq_stat_reset(&stats->idle_time);
bfq_stat_reset(&stats->empty_time);
#endif
}

Expand All @@ -300,14 +418,14 @@ static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from)
blkg_rwstat_add_aux(&to->merged, &from->merged);
blkg_rwstat_add_aux(&to->service_time, &from->service_time);
blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
blkg_stat_add_aux(&from->time, &from->time);
blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
blkg_stat_add_aux(&to->avg_queue_size_samples,
bfq_stat_add_aux(&from->time, &from->time);
bfq_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
bfq_stat_add_aux(&to->avg_queue_size_samples,
&from->avg_queue_size_samples);
blkg_stat_add_aux(&to->dequeue, &from->dequeue);
blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
blkg_stat_add_aux(&to->idle_time, &from->idle_time);
blkg_stat_add_aux(&to->empty_time, &from->empty_time);
bfq_stat_add_aux(&to->dequeue, &from->dequeue);
bfq_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
bfq_stat_add_aux(&to->idle_time, &from->idle_time);
bfq_stat_add_aux(&to->empty_time, &from->empty_time);
#endif
}

Expand Down Expand Up @@ -360,13 +478,13 @@ static void bfqg_stats_exit(struct bfqg_stats *stats)
blkg_rwstat_exit(&stats->service_time);
blkg_rwstat_exit(&stats->wait_time);
blkg_rwstat_exit(&stats->queued);
blkg_stat_exit(&stats->time);
blkg_stat_exit(&stats->avg_queue_size_sum);
blkg_stat_exit(&stats->avg_queue_size_samples);
blkg_stat_exit(&stats->dequeue);
blkg_stat_exit(&stats->group_wait_time);
blkg_stat_exit(&stats->idle_time);
blkg_stat_exit(&stats->empty_time);
bfq_stat_exit(&stats->time);
bfq_stat_exit(&stats->avg_queue_size_sum);
bfq_stat_exit(&stats->avg_queue_size_samples);
bfq_stat_exit(&stats->dequeue);
bfq_stat_exit(&stats->group_wait_time);
bfq_stat_exit(&stats->idle_time);
bfq_stat_exit(&stats->empty_time);
#endif
}

Expand All @@ -377,13 +495,13 @@ static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp)
blkg_rwstat_init(&stats->service_time, gfp) ||
blkg_rwstat_init(&stats->wait_time, gfp) ||
blkg_rwstat_init(&stats->queued, gfp) ||
blkg_stat_init(&stats->time, gfp) ||
blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
blkg_stat_init(&stats->dequeue, gfp) ||
blkg_stat_init(&stats->group_wait_time, gfp) ||
blkg_stat_init(&stats->idle_time, gfp) ||
blkg_stat_init(&stats->empty_time, gfp)) {
bfq_stat_init(&stats->time, gfp) ||
bfq_stat_init(&stats->avg_queue_size_sum, gfp) ||
bfq_stat_init(&stats->avg_queue_size_samples, gfp) ||
bfq_stat_init(&stats->dequeue, gfp) ||
bfq_stat_init(&stats->group_wait_time, gfp) ||
bfq_stat_init(&stats->idle_time, gfp) ||
bfq_stat_init(&stats->empty_time, gfp)) {
bfqg_stats_exit(stats);
return -ENOMEM;
}
Expand Down Expand Up @@ -927,7 +1045,7 @@ static int bfqg_print_rwstat(struct seq_file *sf, void *v)
static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
u64 sum = bfq_stat_recursive_sum(pd_to_blkg(pd),
&blkcg_policy_bfq, off);
return __blkg_prfill_u64(sf, pd, sum);
}
Expand Down Expand Up @@ -996,11 +1114,11 @@ static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
struct bfq_group *bfqg = pd_to_bfqg(pd);
u64 samples = blkg_stat_read(&bfqg->stats.avg_queue_size_samples);
u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples);
u64 v = 0;

if (samples) {
v = blkg_stat_read(&bfqg->stats.avg_queue_size_sum);
v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum);
v = div64_u64(v, samples);
}
__blkg_prfill_u64(sf, pd, v);
Expand Down
19 changes: 12 additions & 7 deletions block/bfq-iosched.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -777,6 +777,11 @@ enum bfqq_expiration {
BFQQE_PREEMPTED /* preemption in progress */
};

struct bfq_stat {
struct percpu_counter cpu_cnt;
atomic64_t aux_cnt;
};

struct bfqg_stats {
#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
/* number of ios merged */
Expand All @@ -788,19 +793,19 @@ struct bfqg_stats {
/* number of IOs queued up */
struct blkg_rwstat queued;
/* total disk time and nr sectors dispatched by this group */
struct blkg_stat time;
struct bfq_stat time;
/* sum of number of ios queued across all samples */
struct blkg_stat avg_queue_size_sum;
struct bfq_stat avg_queue_size_sum;
/* count of samples taken for average */
struct blkg_stat avg_queue_size_samples;
struct bfq_stat avg_queue_size_samples;
/* how many times this group has been removed from service tree */
struct blkg_stat dequeue;
struct bfq_stat dequeue;
/* total time spent waiting for it to be assigned a timeslice. */
struct blkg_stat group_wait_time;
struct bfq_stat group_wait_time;
/* time spent idling for this blkcg_gq */
struct blkg_stat idle_time;
struct bfq_stat idle_time;
/* total time with empty current active q with other requests queued */
struct blkg_stat empty_time;
struct bfq_stat empty_time;
/* fields after this shouldn't be cleared on stat reset */
u64 start_group_wait_time;
u64 start_idle_time;
Expand Down
56 changes: 0 additions & 56 deletions block/blk-cgroup.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -572,20 +572,6 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
}
EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat);

/**
* blkg_prfill_stat - prfill callback for blkg_stat
* @sf: seq_file to print to
* @pd: policy private data of interest
* @off: offset to the blkg_stat in @pd
*
* prfill callback for printing a blkg_stat.
*/
u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off)
{
return __blkg_prfill_u64(sf, pd, blkg_stat_read((void *)pd + off));
}
EXPORT_SYMBOL_GPL(blkg_prfill_stat);

/**
* blkg_prfill_rwstat - prfill callback for blkg_rwstat
* @sf: seq_file to print to
Expand Down Expand Up @@ -687,48 +673,6 @@ int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v)
}
EXPORT_SYMBOL_GPL(blkg_print_stat_ios_recursive);

/**
* blkg_stat_recursive_sum - collect hierarchical blkg_stat
* @blkg: blkg of interest
* @pol: blkcg_policy which contains the blkg_stat
* @off: offset to the blkg_stat in blkg_policy_data or @blkg
*
* Collect the blkg_stat specified by @blkg, @pol and @off and all its
* online descendants and their aux counts. The caller must be holding the
* queue lock for online tests.
*
* If @pol is NULL, blkg_stat is at @off bytes into @blkg; otherwise, it is
* at @off bytes into @blkg's blkg_policy_data of the policy.
*/
u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
struct blkcg_policy *pol, int off)
{
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
u64 sum = 0;

lockdep_assert_held(&blkg->q->queue_lock);

rcu_read_lock();
blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
struct blkg_stat *stat;

if (!pos_blkg->online)
continue;

if (pol)
stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
else
stat = (void *)blkg + off;

sum += blkg_stat_read(stat) + atomic64_read(&stat->aux_cnt);
}
rcu_read_unlock();

return sum;
}
EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);

/**
* blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
* @blkg: blkg of interest
Expand Down
Loading

0 comments on commit c0ce79d

Please sign in to comment.