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| author | Paolo Valente <paolo.valente@linaro.org> | 2021-06-19 16:09:42 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-06-21 15:03:41 -0600 |
| commit | 511a2699237611b062df7798476bf3a1392910b9 (patch) | |
| tree | 52387142d1f1dee29676e7233aafc6c531fff768 /block | |
| parent | 76a8040817b4b9c69b53f9b326987fa891b4082a (diff) | |
| download | linux-stable-511a2699237611b062df7798476bf3a1392910b9.tar.gz linux-stable-511a2699237611b062df7798476bf3a1392910b9.tar.bz2 linux-stable-511a2699237611b062df7798476bf3a1392910b9.zip | |
block, bfq: let also stably merged queues enjoy weight raising
Merged bfq_queues are kept out of weight-raising (low-latency)
mechanisms. The reason is that these queues are usually created for
non-interactive and non-soft-real-time tasks. Yet this is not the case
for stably-merged queues. These queues are merged just because they
are created shortly after each other. So they may easily serve the I/O
of an interactive or soft-real time application, if the application
happens to spawn multiple processes.
To address this issue, this commits lets also stably-merged queued
enjoy weight raising.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Link: https://lore.kernel.org/r/20210619140948.98712-2-paolo.valente@linaro.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/bfq-iosched.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index acd1f881273e..da2363f12e53 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1729,10 +1729,23 @@ static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd, bfqq->entity.new_weight == 40; *interactive = !in_burst && idle_for_long_time && bfqq->entity.new_weight == 40; + /* + * Merged bfq_queues are kept out of weight-raising + * (low-latency) mechanisms. The reason is that these queues + * are usually created for non-interactive and + * non-soft-real-time tasks. Yet this is not the case for + * stably-merged queues. These queues are merged just because + * they are created shortly after each other. So they may + * easily serve the I/O of an interactive or soft-real time + * application, if the application happens to spawn multiple + * processes. So let also stably-merged queued enjoy weight + * raising. + */ wr_or_deserves_wr = bfqd->low_latency && (bfqq->wr_coeff > 1 || (bfq_bfqq_sync(bfqq) && - bfqq->bic && (*interactive || soft_rt))); + (bfqq->bic || RQ_BIC(rq)->stably_merged) && + (*interactive || soft_rt))); /* * Using the last flag, update budget and check whether bfqq |