[PATCH 2/4] block, bfq: avoid moving bfqq to it's parent bfqg
From: Yu Kuai <hidden>
Date: 2021-12-21 03:10:04
Also in:
linux-block, lkml
Subsystem:
bfq i/o scheduler, block layer, control group - block io controller (blkio), the rest · Maintainers:
Yu Kuai, Jens Axboe, Tejun Heo, Josef Bacik, Linus Torvalds
Moving bfqq to it's parent bfqg is pointless. Signed-off-by: Yu Kuai <redacted> --- block/bfq-cgroup.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 24a5c5329bcd..0f62546a72d4 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c@@ -645,6 +645,11 @@ 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 = bfq_group(bfqq); + + /* No point to move bfqq to the same group */ + if (old_parent == bfqg) + return; /* * Get extra reference to prevent bfqq from being freed in
@@ -666,7 +671,7 @@ 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)
--
2.31.1