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| author | Paolo Valente <paolo.valente@linaro.org> | 2019-01-29 12:06:29 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2019-01-31 12:50:23 -0700 |
| commit | 73d58118498b14e4d2f2391105459b997b586ddc (patch) | |
| tree | 71e72676425a3eaa6e6ebe582ce27994d1eafbf2 /block/bfq-wf2q.c | |
| parent | 03e565e4204c6cf8687d995de5cafd0341503b4e (diff) | |
| download | linux-73d58118498b14e4d2f2391105459b997b586ddc.tar.bz2 | |
block, bfq: consider also ioprio classes in symmetry detection
In asymmetric scenarios, i.e., when some bfq_queue or bfq_group needs to
be guaranteed a different bandwidth than other bfq_queues or bfq_groups,
these service guaranteed can be provided only by plugging I/O dispatch,
completely or partially, when the queue in service remains temporarily
empty. A case where asymmetry is particularly strong is when some active
bfq_queues belong to a higher-priority class than some other active
bfq_queues. Unfortunately, this important case is not considered at all
in the code for detecting asymmetric scenarios. This commit adds the
missing logic.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/bfq-wf2q.c')
| -rw-r--r-- | block/bfq-wf2q.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index 72adbbe975d5..ce37d709a34f 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -44,6 +44,12 @@ static unsigned int bfq_class_idx(struct bfq_entity *entity) BFQ_DEFAULT_GRP_CLASS - 1; } +unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd) +{ + return bfqd->busy_queues[0] + bfqd->busy_queues[1] + + bfqd->busy_queues[2]; +} + static struct bfq_entity *bfq_lookup_next_entity(struct bfq_sched_data *sd, bool expiration); @@ -1513,7 +1519,7 @@ struct bfq_queue *bfq_get_next_queue(struct bfq_data *bfqd) struct bfq_sched_data *sd; struct bfq_queue *bfqq; - if (bfqd->busy_queues == 0) + if (bfq_tot_busy_queues(bfqd) == 0) return NULL; /* @@ -1665,7 +1671,7 @@ void bfq_del_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_clear_bfqq_busy(bfqq); - bfqd->busy_queues--; + bfqd->busy_queues[bfqq->ioprio_class - 1]--; if (!bfqq->dispatched) bfq_weights_tree_remove(bfqd, bfqq); @@ -1688,7 +1694,7 @@ void bfq_add_bfqq_busy(struct bfq_data *bfqd, struct bfq_queue *bfqq) bfq_activate_bfqq(bfqd, bfqq); bfq_mark_bfqq_busy(bfqq); - bfqd->busy_queues++; + bfqd->busy_queues[bfqq->ioprio_class - 1]++; if (!bfqq->dispatched) if (bfqq->wr_coeff == 1) |