From: John Garry <john.garry@huawei.com>
Date: Tue, 5 Oct 2021 18:23:28 +0800
Subject: [PATCH] blk-mq: Relocate shared sbitmap resize in
blk_mq_update_nr_requests()
Git-commit: 8fa044640f128c0cd015f72cda42989a664889fc
Patch-mainline: v5.16-rc1
References: jsc#PED-1183
For shared sbitmap, if the call to blk_mq_tag_update_depth() was
successful for any hctx when hctx->sched_tags is not set, then it would be
successful for all (due to nature in which blk_mq_tag_update_depth()
fails).
As such, there is no need to call blk_mq_tag_resize_shared_sbitmap() for
each hctx. So relocate the call until after the hctx iteration under the
!q->elevator check, which is equivalent (to !hctx->sched_tags).
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/1633429419-228500-4-git-send-email-john.garry@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/blk-mq.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 03cbde75756d..240c04aaa3f8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3625,8 +3625,6 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
if (!hctx->sched_tags) {
ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
false);
- if (!ret && blk_mq_is_sbitmap_shared(set->flags))
- blk_mq_tag_resize_shared_sbitmap(set, nr);
} else {
ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
nr, true);
@@ -3644,9 +3642,13 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
}
if (!ret) {
q->nr_requests = nr;
- if (q->elevator && blk_mq_is_sbitmap_shared(set->flags))
- sbitmap_queue_resize(&q->sched_bitmap_tags,
- nr - set->reserved_tags);
+ if (blk_mq_is_sbitmap_shared(set->flags)) {
+ if (q->elevator)
+ sbitmap_queue_resize(&q->sched_bitmap_tags,
+ nr - set->reserved_tags);
+ else
+ blk_mq_tag_resize_shared_sbitmap(set, nr);
+ }
}
blk_mq_unquiesce_queue(q);
--
2.35.3