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 the bio is flagged with BIO_CGROUP_ACCT 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))
+ if (!bio_flagged(bio, BIO_CGROUP_ACCT)) {
+ bio_set_flag(bio, BIO_CGROUP_ACCT);
bis->cur.bytes[rwd] += bio->bi_iter.bi_size;
+ }
bis->cur.ios[rwd]++;
u64_stats_update_end(&bis->sync);
static inline void blkcg_use_delay(struct blkcg_gq *blkg)
{
+ if (WARN_ON_ONCE(atomic_read(&blkg->use_delay) < 0))
+ return;
if (atomic_add_return(1, &blkg->use_delay) == 1)
atomic_inc(&blkg->blkcg->css.cgroup->congestion_count);
}
{
int old = atomic_read(&blkg->use_delay);
+ if (WARN_ON_ONCE(old < 0))
+ return 0;
if (old == 0)
return 0;
return 1;
}
+/**
+ * blkcg_set_delay - Enable allocator delay mechanism with the specified delay amount
+ * @blkg: target blkg
+ * @delay: delay duration in nsecs
+ *
+ * When enabled with this function, the delay is not decayed and must be
+ * explicitly cleared with blkcg_clear_delay(). Must not be mixed with
+ * blkcg_[un]use_delay() and blkcg_add_delay() usages.
+ */
+static inline void blkcg_set_delay(struct blkcg_gq *blkg, u64 delay)
+{
+ int old = atomic_read(&blkg->use_delay);
+
+ /* We only want 1 person setting the congestion count for this blkg. */
+ if (!old && atomic_cmpxchg(&blkg->use_delay, old, -1) == old)
+ atomic_inc(&blkg->blkcg->css.cgroup->congestion_count);
+
+ atomic64_set(&blkg->delay_nsec, delay);
+}
+
+/**
+ * blkcg_clear_delay - Disable allocator delay mechanism
+ * @blkg: target blkg
+ *
+ * Disable use_delay mechanism. See blkcg_set_delay().
+ */
static inline void blkcg_clear_delay(struct blkcg_gq *blkg)
{
int old = atomic_read(&blkg->use_delay);
- if (!old)
- return;
+
/* We only want 1 person clearing the congestion count for this blkg. */
- while (old) {
- int cur = atomic_cmpxchg(&blkg->use_delay, old, 0);
- if (cur == old) {
- atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
- break;
- }
- old = cur;
- }
+ if (old && atomic_cmpxchg(&blkg->use_delay, old, 0) == old)
+ atomic_dec(&blkg->blkcg->css.cgroup->congestion_count);
}
void blkcg_add_delay(struct blkcg_gq *blkg, u64 now, u64 delta);