block: Replace struct rq_depth with unsigned int in struct iolatency_grp

We only need a max queue depth for every iolatency to limit the inflight io
number. Replace struct rq_depth with unsigned int to simplfy "struct
iolatency_grp" and save memory.

Signed-off-by: Kemeng Shi <shikemeng@huawei.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20221018111240.22612-4-shikemeng@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 2c574f9..778a005 100644 (file)
--- 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,
@@ -374,7 +374,7 @@ 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;
@@ -386,12 +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);
        }
 }
 
@@ -444,7 +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;
        }
@@ -452,7 +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;
        }
@@ -507,7 +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);
@@ -919,7 +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);
@@ -927,7 +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)
@@ -944,12 +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,
@@ -993,9 +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);