From eed3ecc991c90a4a0ce32ea2b35378dc351f012b Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Fri, 16 Sep 2022 15:19:40 +0800 Subject: [PATCH] block, bfq: do not idle if only one group is activated Now that root group is counted into 'num_groups_with_pending_reqs', 'num_groups_with_pending_reqs > 0' is always true in bfq_asymmetric_scenario(). Thus change the condition to '> 1'. On the other hand, this change can enable concurrent sync io if only one group is activated. Signed-off-by: Yu Kuai Reviewed-by: Jan Kara Acked-by: Paolo Valente Link: https://lore.kernel.org/r/20220916071942.214222-5-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe --- block/bfq-iosched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index d5febdb..850becc 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -820,7 +820,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) * much easier to maintain the needed state: * 1) all active queues have the same weight, * 2) all active queues belong to the same I/O-priority class, - * 3) there are no active groups. + * 3) there is at most one active group. * In particular, the last condition is always true if hierarchical * support or the cgroups interface are not enabled, thus no state * needs to be maintained in this case. @@ -852,7 +852,7 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, return varied_queue_weights || multiple_classes_busy #ifdef CONFIG_BFQ_GROUP_IOSCHED - || bfqd->num_groups_with_pending_reqs > 0 + || bfqd->num_groups_with_pending_reqs > 1 #endif ; } -- 2.7.4