From c5e4cb0fcbbaa5ad853818c4a2383e9bd147fad6 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Sat, 29 Jan 2022 09:59:23 +0800 Subject: block, bfq: avoid moving bfqq to it's parent bfqg Moving bfqq to it's parent bfqg is pointless. Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20220129015924.3958918-3-yukuai3@huawei.com Signed-off-by: Jens Axboe --- block/bfq-cgroup.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 24a5c5329bcd..9783c1156159 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -645,6 +645,14 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, struct bfq_group *bfqg) { struct bfq_entity *entity = &bfqq->entity; + struct bfq_group *old_parent = bfqq_group(bfqq); + + /* + * No point to move bfqq to the same group, which can happen when + * root group is offlined + */ + if (old_parent == bfqg) + return; /* * Get extra reference to prevent bfqq from being freed in @@ -666,7 +674,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_deactivate_bfqq(bfqd, bfqq, false, false); else if (entity->on_st_or_in_serv) bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); - bfqg_and_blkg_put(bfqq_group(bfqq)); + bfqg_and_blkg_put(old_parent); if (entity->parent && entity->parent->last_bfqq_created == bfqq) -- cgit v1.2.3