From 73d58118498b14e4d2f2391105459b997b586ddc Mon Sep 17 00:00:00 2001 From: Paolo Valente Date: Tue, 29 Jan 2019 12:06:29 +0100 Subject: 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 Signed-off-by: Jens Axboe --- block/bfq-iosched.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'block/bfq-iosched.h') diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h index 0b02bf302de0..30be669be465 100644 --- a/block/bfq-iosched.h +++ b/block/bfq-iosched.h @@ -501,10 +501,11 @@ struct bfq_data { unsigned int num_groups_with_pending_reqs; /* - * Number of bfq_queues containing requests (including the - * queue in service, even if it is idling). + * Per-class (RT, BE, IDLE) number of bfq_queues containing + * requests (including the queue in service, even if it is + * idling). */ - int busy_queues; + unsigned int busy_queues[3]; /* number of weight-raised busy @bfq_queues */ int wr_busy_queues; /* number of queued requests */ @@ -974,6 +975,7 @@ extern struct blkcg_policy blkcg_policy_bfq; struct bfq_group *bfq_bfqq_to_bfqg(struct bfq_queue *bfqq); struct bfq_queue *bfq_entity_to_bfqq(struct bfq_entity *entity); +unsigned int bfq_tot_busy_queues(struct bfq_data *bfqd); struct bfq_service_tree *bfq_entity_service_tree(struct bfq_entity *entity); struct bfq_entity *bfq_entity_of(struct rb_node *node); unsigned short bfq_ioprio_to_weight(int ioprio); -- cgit v1.2.3-70-g09d2