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authorShaohua Li <shli@fb.com>2017-05-17 13:07:25 -0700
committerJens Axboe <axboe@fb.com>2017-05-22 14:47:12 -0600
commit4cff729f62d1bd433178f1ffe09db5718835e925 (patch)
tree72eeb164fa318bc34b72ab8a3102e1591a54eb65 /block/blk-throttle.c
parent5b81fc3cc625e857275573cb4240bbab553f919c (diff)
downloadlinux-0-day-4cff729f62d1bd433178f1ffe09db5718835e925.tar.gz
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.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 16174f8..1f8d62f 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)