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-rw-r--r--block/blk-cgroup.c124
-rw-r--r--include/linux/blk-cgroup.h48
2 files changed, 142 insertions, 30 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index e7e93377e320..b3429be62057 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -80,8 +80,7 @@ static void blkg_free(struct blkcg_gq *blkg)
if (blkg->pd[i])
blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
- blkg_rwstat_exit(&blkg->stat_ios);
- blkg_rwstat_exit(&blkg->stat_bytes);
+ free_percpu(blkg->iostat_cpu);
percpu_ref_exit(&blkg->refcnt);
kfree(blkg);
}
@@ -146,7 +145,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
gfp_t gfp_mask)
{
struct blkcg_gq *blkg;
- int i;
+ int i, cpu;
/* alloc and init base part */
blkg = kzalloc_node(sizeof(*blkg), gfp_mask, q->node);
@@ -156,8 +155,8 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
if (percpu_ref_init(&blkg->refcnt, blkg_release, 0, gfp_mask))
goto err_free;
- if (blkg_rwstat_init(&blkg->stat_bytes, gfp_mask) ||
- blkg_rwstat_init(&blkg->stat_ios, gfp_mask))
+ blkg->iostat_cpu = alloc_percpu_gfp(struct blkg_iostat_set, gfp_mask);
+ if (!blkg->iostat_cpu)
goto err_free;
blkg->q = q;
@@ -167,6 +166,10 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
INIT_WORK(&blkg->async_bio_work, blkg_async_bio_workfn);
blkg->blkcg = blkcg;
+ u64_stats_init(&blkg->iostat.sync);
+ for_each_possible_cpu(cpu)
+ u64_stats_init(&per_cpu_ptr(blkg->iostat_cpu, cpu)->sync);
+
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
struct blkg_policy_data *pd;
@@ -393,7 +396,6 @@ struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
static void blkg_destroy(struct blkcg_gq *blkg)
{
struct blkcg *blkcg = blkg->blkcg;
- struct blkcg_gq *parent = blkg->parent;
int i;
lockdep_assert_held(&blkg->q->queue_lock);
@@ -410,11 +412,6 @@ static void blkg_destroy(struct blkcg_gq *blkg)
pol->pd_offline_fn(blkg->pd[i]);
}
- if (parent) {
- blkg_rwstat_add_aux(&parent->stat_bytes, &blkg->stat_bytes);
- blkg_rwstat_add_aux(&parent->stat_ios, &blkg->stat_ios);
- }
-
blkg->online = false;
radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
@@ -464,7 +461,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
{
struct blkcg *blkcg = css_to_blkcg(css);
struct blkcg_gq *blkg;
- int i;
+ int i, cpu;
mutex_lock(&blkcg_pol_mutex);
spin_lock_irq(&blkcg->lock);
@@ -475,8 +472,12 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
* anyway. If you get hit by a race, retry.
*/
hlist_for_each_entry(blkg, &blkcg->blkg_list, blkcg_node) {
- blkg_rwstat_reset(&blkg->stat_bytes);
- blkg_rwstat_reset(&blkg->stat_ios);
+ for_each_possible_cpu(cpu) {
+ struct blkg_iostat_set *bis =
+ per_cpu_ptr(blkg->iostat_cpu, cpu);
+ memset(bis, 0, sizeof(*bis));
+ }
+ memset(&blkg->iostat, 0, sizeof(blkg->iostat));
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
@@ -840,16 +841,18 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
struct blkcg *blkcg = css_to_blkcg(seq_css(sf));
struct blkcg_gq *blkg;
+ cgroup_rstat_flush(blkcg->css.cgroup);
rcu_read_lock();
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ struct blkg_iostat_set *bis = &blkg->iostat;
const char *dname;
char *buf;
- struct blkg_rwstat_sample rwstat;
u64 rbytes, wbytes, rios, wios, dbytes, dios;
size_t size = seq_get_buf(sf, &buf), off = 0;
int i;
bool has_stats = false;
+ unsigned seq;
spin_lock_irq(&blkg->q->queue_lock);
@@ -868,17 +871,16 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
*/
off += scnprintf(buf+off, size-off, "%s ", dname);
- blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_bytes), &rwstat);
- rbytes = rwstat.cnt[BLKG_RWSTAT_READ];
- wbytes = rwstat.cnt[BLKG_RWSTAT_WRITE];
- dbytes = rwstat.cnt[BLKG_RWSTAT_DISCARD];
+ do {
+ seq = u64_stats_fetch_begin(&bis->sync);
- blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_ios), &rwstat);
- rios = rwstat.cnt[BLKG_RWSTAT_READ];
- wios = rwstat.cnt[BLKG_RWSTAT_WRITE];
- dios = rwstat.cnt[BLKG_RWSTAT_DISCARD];
+ rbytes = bis->cur.bytes[BLKG_IOSTAT_READ];
+ wbytes = bis->cur.bytes[BLKG_IOSTAT_WRITE];
+ dbytes = bis->cur.bytes[BLKG_IOSTAT_DISCARD];
+ rios = bis->cur.ios[BLKG_IOSTAT_READ];
+ wios = bis->cur.ios[BLKG_IOSTAT_WRITE];
+ dios = bis->cur.ios[BLKG_IOSTAT_DISCARD];
+ } while (u64_stats_fetch_retry(&bis->sync, seq));
if (rbytes || wbytes || rios || wios) {
has_stats = true;
@@ -1214,6 +1216,77 @@ static int blkcg_can_attach(struct cgroup_taskset *tset)
return ret;
}
+static void blkg_iostat_set(struct blkg_iostat *dst, struct blkg_iostat *src)
+{
+ int i;
+
+ for (i = 0; i < BLKG_IOSTAT_NR; i++) {
+ dst->bytes[i] = src->bytes[i];
+ dst->ios[i] = src->ios[i];
+ }
+}
+
+static void blkg_iostat_add(struct blkg_iostat *dst, struct blkg_iostat *src)
+{
+ int i;
+
+ for (i = 0; i < BLKG_IOSTAT_NR; i++) {
+ dst->bytes[i] += src->bytes[i];
+ dst->ios[i] += src->ios[i];
+ }
+}
+
+static void blkg_iostat_sub(struct blkg_iostat *dst, struct blkg_iostat *src)
+{
+ int i;
+
+ for (i = 0; i < BLKG_IOSTAT_NR; i++) {
+ dst->bytes[i] -= src->bytes[i];
+ dst->ios[i] -= src->ios[i];
+ }
+}
+
+static void blkcg_rstat_flush(struct cgroup_subsys_state *css, int cpu)
+{
+ struct blkcg *blkcg = css_to_blkcg(css);
+ struct blkcg_gq *blkg;
+
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
+ struct blkcg_gq *parent = blkg->parent;
+ struct blkg_iostat_set *bisc = per_cpu_ptr(blkg->iostat_cpu, cpu);
+ struct blkg_iostat cur, delta;
+ unsigned seq;
+
+ /* fetch the current per-cpu values */
+ do {
+ seq = u64_stats_fetch_begin(&bisc->sync);
+ blkg_iostat_set(&cur, &bisc->cur);
+ } while (u64_stats_fetch_retry(&bisc->sync, seq));
+
+ /* propagate percpu delta to global */
+ u64_stats_update_begin(&blkg->iostat.sync);
+ blkg_iostat_set(&delta, &cur);
+ blkg_iostat_sub(&delta, &bisc->last);
+ blkg_iostat_add(&blkg->iostat.cur, &delta);
+ blkg_iostat_add(&bisc->last, &delta);
+ u64_stats_update_end(&blkg->iostat.sync);
+
+ /* propagate global delta to parent */
+ if (parent) {
+ u64_stats_update_begin(&parent->iostat.sync);
+ blkg_iostat_set(&delta, &blkg->iostat.cur);
+ blkg_iostat_sub(&delta, &blkg->iostat.last);
+ blkg_iostat_add(&parent->iostat.cur, &delta);
+ blkg_iostat_add(&blkg->iostat.last, &delta);
+ u64_stats_update_end(&parent->iostat.sync);
+ }
+ }
+
+ rcu_read_unlock();
+}
+
static void blkcg_bind(struct cgroup_subsys_state *root_css)
{
int i;
@@ -1246,6 +1319,7 @@ struct cgroup_subsys io_cgrp_subsys = {
.css_offline = blkcg_css_offline,
.css_free = blkcg_css_free,
.can_attach = blkcg_can_attach,
+ .css_rstat_flush = blkcg_rstat_flush,
.bind = blkcg_bind,
.dfl_cftypes = blkcg_files,
.legacy_cftypes = blkcg_legacy_files,
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 914ce55fa8c2..867ab391e409 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -15,7 +15,9 @@
*/
#include <linux/cgroup.h>
+#include <linux/percpu.h>
#include <linux/percpu_counter.h>
+#include <linux/u64_stats_sync.h>
#include <linux/seq_file.h>
#include <linux/radix-tree.h>
#include <linux/blkdev.h>
@@ -31,6 +33,14 @@
#ifdef CONFIG_BLK_CGROUP
+enum blkg_iostat_type {
+ BLKG_IOSTAT_READ,
+ BLKG_IOSTAT_WRITE,
+ BLKG_IOSTAT_DISCARD,
+
+ BLKG_IOSTAT_NR,
+};
+
enum blkg_rwstat_type {
BLKG_RWSTAT_READ,
BLKG_RWSTAT_WRITE,
@@ -61,6 +71,17 @@ struct blkcg {
#endif
};
+struct blkg_iostat {
+ u64 bytes[BLKG_IOSTAT_NR];
+ u64 ios[BLKG_IOSTAT_NR];
+};
+
+struct blkg_iostat_set {
+ struct u64_stats_sync sync;
+ struct blkg_iostat cur;
+ struct blkg_iostat last;
+};
+
/*
* blkg_[rw]stat->aux_cnt is excluded for local stats but included for
* recursive. Used to carry stats of dead children.
@@ -127,8 +148,8 @@ struct blkcg_gq {
/* is this blkg online? protected by both blkcg and q locks */
bool online;
- struct blkg_rwstat stat_bytes;
- struct blkg_rwstat stat_ios;
+ struct blkg_iostat_set __percpu *iostat_cpu;
+ struct blkg_iostat_set iostat;
struct blkg_policy_data *pd[BLKCG_MAX_POLS];
@@ -740,15 +761,32 @@ static inline bool blkcg_bio_issue_check(struct request_queue *q,
throtl = blk_throtl_bio(q, blkg, bio);
if (!throtl) {
+ struct blkg_iostat_set *bis;
+ int rwd, cpu;
+
+ if (op_is_discard(bio->bi_opf))
+ rwd = BLKG_IOSTAT_DISCARD;
+ else if (op_is_write(bio->bi_opf))
+ rwd = BLKG_IOSTAT_WRITE;
+ else
+ rwd = BLKG_IOSTAT_READ;
+
+ cpu = get_cpu();
+ bis = per_cpu_ptr(blkg->iostat_cpu, cpu);
+ u64_stats_update_begin(&bis->sync);
+
/*
* If the bio is flagged with BIO_QUEUE_ENTERED it means this
* is a split bio and we would have already accounted for the
* size of the bio.
*/
if (!bio_flagged(bio, BIO_QUEUE_ENTERED))
- blkg_rwstat_add(&blkg->stat_bytes, bio->bi_opf,
- bio->bi_iter.bi_size);
- blkg_rwstat_add(&blkg->stat_ios, bio->bi_opf, 1);
+ bis->cur.bytes[rwd] += bio->bi_iter.bi_size;
+ bis->cur.ios[rwd]++;
+
+ u64_stats_update_end(&bis->sync);
+ cgroup_rstat_updated(blkg->blkcg->css.cgroup, cpu);
+ put_cpu();
}
blkcg_bio_issue_init(bio);
generated by cgit (git 2.34.1) at 2024-06-09 20:18:19 +0000