diff options
| author |   Jan Kara <jack@suse.cz> | 2021-11-25 14:36:40 +0100 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2021-11-29 06:39:31 -0700 |
| commit | 1eb17f5e15b73669df635fb07df2853cb1244a69 (patch) | |
| tree | 2ee1262e2fcdda982a1109cf027190554c9bdcca /block/bfq-iosched.c | |
| parent | bfq: Provide helper to generate bfqq name (diff) | |
| download | linux-dev-1eb17f5e15b73669df635fb07df2853cb1244a69.tar.xz linux-dev-1eb17f5e15b73669df635fb07df2853cb1244a69.zip | |
bfq: Log waker detections
Waker - wakee relationships are important in deciding whether one queue
can preempt the other one. Print information about detected waker-wakee
relationships so that scheduling decisions can be better understood from
block traces.
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211125133645.27483-7-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-iosched.c')
| -rw-r--r-- | block/bfq-iosched.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 83a2225e407b..69144003a694 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2127,6 +2127,8 @@ static void bfq_update_io_intensity(struct bfq_queue *bfqq, u64 now_ns) static void bfq_check_waker(struct bfq_data *bfqd, struct bfq_queue *bfqq, u64 now_ns) { + char waker_name[MAX_BFQQ_NAME_LENGTH]; + if (!bfqd->last_completed_rq_bfqq || bfqd->last_completed_rq_bfqq == bfqq || bfq_bfqq_has_short_ttime(bfqq) || @@ -2154,12 +2156,18 @@ static void bfq_check_waker(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfqd->last_completed_rq_bfqq; bfqq->num_waker_detections = 1; bfqq->waker_detection_started = now_ns; + bfq_bfqq_name(bfqq->tentative_waker_bfqq, waker_name, + MAX_BFQQ_NAME_LENGTH); + bfq_log_bfqq(bfqd, bfqq, "set tenative waker %s", waker_name); } else /* Same tentative waker queue detected again */ bfqq->num_waker_detections++; if (bfqq->num_waker_detections == 3) { bfqq->waker_bfqq = bfqd->last_completed_rq_bfqq; bfqq->tentative_waker_bfqq = NULL; + bfq_bfqq_name(bfqq->waker_bfqq, waker_name, + MAX_BFQQ_NAME_LENGTH); + bfq_log_bfqq(bfqd, bfqq, "set waker %s", waker_name); /* * If the waker queue disappears, then |