diff options
| author | Shaohua Li <shli@fb.com> | 2017-05-17 13:07:25 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-05-22 14:47:12 -0600 |
| commit | 4cff729f62d1bd433178f1ffe09db5718835e925 (patch) | |
| tree | 72eeb164fa318bc34b72ab8a3102e1591a54eb65 /block/blk-throttle.c | |
| parent | 5b81fc3cc625e857275573cb4240bbab553f919c (diff) | |
| download | lwn-4cff729f62d1bd433178f1ffe09db5718835e925.tar.gz lwn-4cff729f62d1bd433178f1ffe09db5718835e925.zip | |
blk-throttle: output some debug info in trace
These info are important to understand what's happening and help debug.
Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-throttle.c')
| -rw-r--r-- | block/blk-throttle.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 16174f8cb0a1..1f8d62f5e808 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1748,12 +1748,18 @@ static bool throtl_tg_is_idle(struct throtl_grp *tg) * - IO latency is largely below threshold */ unsigned long time = jiffies_to_usecs(4 * tg->td->throtl_slice); + bool ret; time = min_t(unsigned long, MAX_IDLE_TIME, time); - return (ktime_get_ns() >> 10) - tg->last_finish_time > time || + ret = (ktime_get_ns() >> 10) - tg->last_finish_time > time || tg->avg_idletime > tg->idletime_threshold || (tg->latency_target && tg->bio_cnt && tg->bad_bio_cnt * 5 < tg->bio_cnt); + throtl_log(&tg->service_queue, + "avg_idle=%ld, idle_threshold=%ld, bad_bio=%d, total_bio=%d, is_idle=%d, scale=%d", + tg->avg_idletime, tg->idletime_threshold, tg->bad_bio_cnt, + tg->bio_cnt, ret, tg->td->scale); + return ret; } static bool throtl_tg_can_upgrade(struct throtl_grp *tg) @@ -1849,6 +1855,7 @@ static void throtl_upgrade_state(struct throtl_data *td) struct cgroup_subsys_state *pos_css; struct blkcg_gq *blkg; + throtl_log(&td->service_queue, "upgrade to max"); td->limit_index = LIMIT_MAX; td->low_upgrade_time = jiffies; td->scale = 0; @@ -1871,6 +1878,7 @@ static void throtl_downgrade_state(struct throtl_data *td, int new) { td->scale /= 2; + throtl_log(&td->service_queue, "downgrade, scale %d", td->scale); if (td->scale) { td->low_upgrade_time = jiffies - td->scale * td->throtl_slice; return; @@ -2044,6 +2052,11 @@ static void throtl_update_latency_buckets(struct throtl_data *td) td->avg_buckets[i].valid = true; last_latency = td->avg_buckets[i].latency; } + + for (i = 0; i < LATENCY_BUCKET_SIZE; i++) + throtl_log(&td->service_queue, + "Latency bucket %d: latency=%ld, valid=%d", i, + td->avg_buckets[i].latency, td->avg_buckets[i].valid); } #else static inline void throtl_update_latency_buckets(struct throtl_data *td) |