diff options
Diffstat (limited to 'block/blk-iolatency.c')
| -rw-r--r-- | block/blk-iolatency.c | 37 |
1 files changed, 17 insertions, 20 deletions
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c index 571fa95aafe9..778a0057193e 100644 --- a/block/blk-iolatency.c +++ b/block/blk-iolatency.c @@ -141,7 +141,7 @@ struct iolatency_grp { struct latency_stat __percpu *stats; struct latency_stat cur_stat; struct blk_iolatency *blkiolat; - struct rq_depth rq_depth; + unsigned int max_depth; struct rq_wait rq_wait; atomic64_t window_start; atomic_t scale_cookie; @@ -280,7 +280,7 @@ static void iolat_cleanup_cb(struct rq_wait *rqw, void *private_data) static bool iolat_acquire_inflight(struct rq_wait *rqw, void *private_data) { struct iolatency_grp *iolat = private_data; - return rq_wait_inc_below(rqw, iolat->rq_depth.max_depth); + return rq_wait_inc_below(rqw, iolat->max_depth); } static void __blkcg_iolatency_throttle(struct rq_qos *rqos, @@ -364,15 +364,17 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat, } /* - * Change the queue depth of the iolatency_grp. We add/subtract 1/16th of the + * Change the queue depth of the iolatency_grp. We add 1/16th of the * queue depth at a time so we don't get wild swings and hopefully dial in to - * fairer distribution of the overall queue depth. + * fairer distribution of the overall queue depth. We halve the queue depth + * at a time so we can scale down queue depth quickly from default unlimited + * to target. */ static void scale_change(struct iolatency_grp *iolat, bool up) { unsigned long qd = iolat->blkiolat->rqos.q->nr_requests; unsigned long scale = scale_amount(qd, up); - unsigned long old = iolat->rq_depth.max_depth; + unsigned long old = iolat->max_depth; if (old > qd) old = qd; @@ -384,12 +386,12 @@ static void scale_change(struct iolatency_grp *iolat, bool up) if (old < qd) { old += scale; old = min(old, qd); - iolat->rq_depth.max_depth = old; + iolat->max_depth = old; wake_up_all(&iolat->rq_wait.wait); } } else { old >>= 1; - iolat->rq_depth.max_depth = max(old, 1UL); + iolat->max_depth = max(old, 1UL); } } @@ -403,9 +405,6 @@ static void check_scale_change(struct iolatency_grp *iolat) u64 scale_lat; int direction = 0; - if (lat_to_blkg(iolat)->parent == NULL) - return; - parent = blkg_to_lat(lat_to_blkg(iolat)->parent); if (!parent) return; @@ -445,7 +444,7 @@ static void check_scale_change(struct iolatency_grp *iolat) } /* We're as low as we can go. */ - if (iolat->rq_depth.max_depth == 1 && direction < 0) { + if (iolat->max_depth == 1 && direction < 0) { blkcg_use_delay(lat_to_blkg(iolat)); return; } @@ -453,7 +452,7 @@ static void check_scale_change(struct iolatency_grp *iolat) /* We're back to the default cookie, unthrottle all the things. */ if (cur_cookie == DEFAULT_SCALE_COOKIE) { blkcg_clear_delay(lat_to_blkg(iolat)); - iolat->rq_depth.max_depth = UINT_MAX; + iolat->max_depth = UINT_MAX; wake_up_all(&iolat->rq_wait.wait); return; } @@ -508,7 +507,7 @@ static void iolatency_record_time(struct iolatency_grp *iolat, * We don't want to count issue_as_root bio's in the cgroups latency * statistics as it could skew the numbers downwards. */ - if (unlikely(issue_as_root && iolat->rq_depth.max_depth != UINT_MAX)) { + if (unlikely(issue_as_root && iolat->max_depth != UINT_MAX)) { u64 sub = iolat->min_lat_nsec; if (req_time < sub) blkcg_add_delay(lat_to_blkg(iolat), now, sub - req_time); @@ -920,7 +919,7 @@ static void iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s) } preempt_enable(); - if (iolat->rq_depth.max_depth == UINT_MAX) + if (iolat->max_depth == UINT_MAX) seq_printf(s, " missed=%llu total=%llu depth=max", (unsigned long long)stat.ps.missed, (unsigned long long)stat.ps.total); @@ -928,7 +927,7 @@ static void iolatency_ssd_stat(struct iolatency_grp *iolat, struct seq_file *s) seq_printf(s, " missed=%llu total=%llu depth=%u", (unsigned long long)stat.ps.missed, (unsigned long long)stat.ps.total, - iolat->rq_depth.max_depth); + iolat->max_depth); } static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) @@ -945,12 +944,12 @@ static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s) avg_lat = div64_u64(iolat->lat_avg, NSEC_PER_USEC); cur_win = div64_u64(iolat->cur_win_nsec, NSEC_PER_MSEC); - if (iolat->rq_depth.max_depth == UINT_MAX) + if (iolat->max_depth == UINT_MAX) seq_printf(s, " depth=max avg_lat=%llu win=%llu", avg_lat, cur_win); else seq_printf(s, " depth=%u avg_lat=%llu win=%llu", - iolat->rq_depth.max_depth, avg_lat, cur_win); + iolat->max_depth, avg_lat, cur_win); } static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp, @@ -994,9 +993,7 @@ static void iolatency_pd_init(struct blkg_policy_data *pd) latency_stat_init(iolat, &iolat->cur_stat); rq_wait_init(&iolat->rq_wait); spin_lock_init(&iolat->child_lat.lock); - iolat->rq_depth.queue_depth = blkg->q->nr_requests; - iolat->rq_depth.max_depth = UINT_MAX; - iolat->rq_depth.default_depth = iolat->rq_depth.queue_depth; + iolat->max_depth = UINT_MAX; iolat->blkiolat = blkiolat; iolat->cur_win_nsec = 100 * NSEC_PER_MSEC; atomic64_set(&iolat->window_start, now); |