Release 4.17 block/blk-stat.c
/*
* Block stat tracking code
*
* Copyright (C) 2016 Jens Axboe
*/
#include <linux/kernel.h>
#include <linux/rculist.h>
#include <linux/blk-mq.h>
#include "blk-stat.h"
#include "blk-mq.h"
#include "blk.h"
struct blk_queue_stats {
struct list_head callbacks;
spinlock_t lock;
bool enable_accounting;
};
static void blk_stat_init(struct blk_rq_stat *stat)
{
stat->min = -1ULL;
stat->max = stat->nr_samples = stat->mean = 0;
stat->batch = 0;
}
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/* src is a per-cpu stat, mean isn't initialized */
static void blk_stat_sum(struct blk_rq_stat *dst, struct blk_rq_stat *src)
{
if (!src->nr_samples)
return;
dst->min = min(dst->min, src->min);
dst->max = max(dst->max, src->max);
dst->mean = div_u64(src->batch + dst->mean * dst->nr_samples,
dst->nr_samples + src->nr_samples);
dst->nr_samples += src->nr_samples;
}
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Jens Axboe | 87 | 97.75% | 1 | 50.00% |
Shaohua Li | 2 | 2.25% | 1 | 50.00% |
Total | 89 | 100.00% | 2 | 100.00% |
static void __blk_stat_add(struct blk_rq_stat *stat, u64 value)
{
stat->min = min(stat->min, value);
stat->max = max(stat->max, value);
stat->batch += value;
stat->nr_samples++;
}
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Omar Sandoval | 44 | 86.27% | 1 | 33.33% |
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Shaohua Li | 1 | 1.96% | 1 | 33.33% |
Total | 51 | 100.00% | 3 | 100.00% |
void blk_stat_add(struct request *rq)
{
struct request_queue *q = rq->q;
struct blk_stat_callback *cb;
struct blk_rq_stat *stat;
int bucket;
u64 now, value;
now = __blk_stat_time(ktime_to_ns(ktime_get()));
if (now < blk_stat_time(&rq->issue_stat))
return;
value = now - blk_stat_time(&rq->issue_stat);
blk_throtl_stat_add(rq, value);
rcu_read_lock();
list_for_each_entry_rcu(cb, &q->stats->callbacks, list) {
if (!blk_stat_is_active(cb))
continue;
bucket = cb->bucket_fn(rq);
if (bucket < 0)
continue;
stat = &get_cpu_ptr(cb->cpu_stat)[bucket];
__blk_stat_add(stat, value);
put_cpu_ptr(cb->cpu_stat);
}
rcu_read_unlock();
}
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Omar Sandoval | 82 | 55.41% | 1 | 14.29% |
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Stephen Bates | 7 | 4.73% | 1 | 14.29% |
Total | 148 | 100.00% | 7 | 100.00% |
static void blk_stat_timer_fn(struct timer_list *t)
{
struct blk_stat_callback *cb = from_timer(cb, t, timer);
unsigned int bucket;
int cpu;
for (bucket = 0; bucket < cb->buckets; bucket++)
blk_stat_init(&cb->stat[bucket]);
for_each_online_cpu(cpu) {
struct blk_rq_stat *cpu_stat;
cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
for (bucket = 0; bucket < cb->buckets; bucket++) {
blk_stat_sum(&cb->stat[bucket], &cpu_stat[bucket]);
blk_stat_init(&cpu_stat[bucket]);
}
}
cb->timer_fn(cb);
}
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Omar Sandoval | 77 | 59.23% | 1 | 25.00% |
Jens Axboe | 41 | 31.54% | 2 | 50.00% |
Kees Cook | 12 | 9.23% | 1 | 25.00% |
Total | 130 | 100.00% | 4 | 100.00% |
struct blk_stat_callback *
blk_stat_alloc_callback(void (*timer_fn)(struct blk_stat_callback *),
int (*bucket_fn)(const struct request *),
unsigned int buckets, void *data)
{
struct blk_stat_callback *cb;
cb = kmalloc(sizeof(*cb), GFP_KERNEL);
if (!cb)
return NULL;
cb->stat = kmalloc_array(buckets, sizeof(struct blk_rq_stat),
GFP_KERNEL);
if (!cb->stat) {
kfree(cb);
return NULL;
}
cb->cpu_stat = __alloc_percpu(buckets * sizeof(struct blk_rq_stat),
__alignof__(struct blk_rq_stat));
if (!cb->cpu_stat) {
kfree(cb->stat);
kfree(cb);
return NULL;
}
cb->timer_fn = timer_fn;
cb->bucket_fn = bucket_fn;
cb->data = data;
cb->buckets = buckets;
timer_setup(&cb->timer, blk_stat_timer_fn, 0);
return cb;
}
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Omar Sandoval | 112 | 61.54% | 1 | 25.00% |
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Stephen Bates | 20 | 10.99% | 1 | 25.00% |
Kees Cook | 2 | 1.10% | 1 | 25.00% |
Total | 182 | 100.00% | 4 | 100.00% |
EXPORT_SYMBOL_GPL(blk_stat_alloc_callback);
void blk_stat_add_callback(struct request_queue *q,
struct blk_stat_callback *cb)
{
unsigned int bucket;
int cpu;
for_each_possible_cpu(cpu) {
struct blk_rq_stat *cpu_stat;
cpu_stat = per_cpu_ptr(cb->cpu_stat, cpu);
for (bucket = 0; bucket < cb->buckets; bucket++)
blk_stat_init(&cpu_stat[bucket]);
}
spin_lock(&q->stats->lock);
list_add_tail_rcu(&cb->list, &q->stats->callbacks);
blk_queue_flag_set(QUEUE_FLAG_STATS, q);
spin_unlock(&q->stats->lock);
}
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Omar Sandoval | 89 | 80.91% | 1 | 33.33% |
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Bart Van Assche | 1 | 0.91% | 1 | 33.33% |
Total | 110 | 100.00% | 3 | 100.00% |
EXPORT_SYMBOL_GPL(blk_stat_add_callback);
void blk_stat_remove_callback(struct request_queue *q,
struct blk_stat_callback *cb)
{
spin_lock(&q->stats->lock);
list_del_rcu(&cb->list);
if (list_empty(&q->stats->callbacks) && !q->stats->enable_accounting)
blk_queue_flag_clear(QUEUE_FLAG_STATS, q);
spin_unlock(&q->stats->lock);
del_timer_sync(&cb->timer);
}
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Person | Tokens | Prop | Commits | CommitProp |
Omar Sandoval | 37 | 48.05% | 1 | 25.00% |
Jens Axboe | 32 | 41.56% | 1 | 25.00% |
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Bart Van Assche | 1 | 1.30% | 1 | 25.00% |
Total | 77 | 100.00% | 4 | 100.00% |
EXPORT_SYMBOL_GPL(blk_stat_remove_callback);
static void blk_stat_free_callback_rcu(struct rcu_head *head)
{
struct blk_stat_callback *cb;
cb = container_of(head, struct blk_stat_callback, rcu);
free_percpu(cb->cpu_stat);
kfree(cb->stat);
kfree(cb);
}
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Jens Axboe | 24 | 51.06% | 1 | 50.00% |
Omar Sandoval | 23 | 48.94% | 1 | 50.00% |
Total | 47 | 100.00% | 2 | 100.00% |
void blk_stat_free_callback(struct blk_stat_callback *cb)
{
if (cb)
call_rcu(&cb->rcu, blk_stat_free_callback_rcu);
}
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Omar Sandoval | 14 | 58.33% | 1 | 33.33% |
Jens Axboe | 10 | 41.67% | 2 | 66.67% |
Total | 24 | 100.00% | 3 | 100.00% |
EXPORT_SYMBOL_GPL(blk_stat_free_callback);
void blk_stat_enable_accounting(struct request_queue *q)
{
spin_lock(&q->stats->lock);
q->stats->enable_accounting = true;
blk_queue_flag_set(QUEUE_FLAG_STATS, q);
spin_unlock(&q->stats->lock);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Shaohua Li | 44 | 97.78% | 1 | 50.00% |
Bart Van Assche | 1 | 2.22% | 1 | 50.00% |
Total | 45 | 100.00% | 2 | 100.00% |
struct blk_queue_stats *blk_alloc_queue_stats(void)
{
struct blk_queue_stats *stats;
stats = kmalloc(sizeof(*stats), GFP_KERNEL);
if (!stats)
return NULL;
INIT_LIST_HEAD(&stats->callbacks);
spin_lock_init(&stats->lock);
stats->enable_accounting = false;
return stats;
}
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Omar Sandoval | 44 | 73.33% | 1 | 33.33% |
Jens Axboe | 10 | 16.67% | 1 | 33.33% |
Shaohua Li | 6 | 10.00% | 1 | 33.33% |
Total | 60 | 100.00% | 3 | 100.00% |
void blk_free_queue_stats(struct blk_queue_stats *stats)
{
if (!stats)
return;
WARN_ON(!list_empty(&stats->callbacks));
kfree(stats);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Omar Sandoval | 17 | 51.52% | 1 | 50.00% |
Jens Axboe | 16 | 48.48% | 1 | 50.00% |
Total | 33 | 100.00% | 2 | 100.00% |
Overall Contributors
Person | Tokens | Prop | Commits | CommitProp |
Omar Sandoval | 609 | 55.92% | 1 | 10.00% |
Jens Axboe | 361 | 33.15% | 4 | 40.00% |
Shaohua Li | 75 | 6.89% | 2 | 20.00% |
Stephen Bates | 27 | 2.48% | 1 | 10.00% |
Kees Cook | 14 | 1.29% | 1 | 10.00% |
Bart Van Assche | 3 | 0.28% | 1 | 10.00% |
Total | 1089 | 100.00% | 10 | 100.00% |
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