From 7d337eef4affc5e26e0570513168c69ddbc40f92 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Thu, 21 Aug 2025 14:06:11 +0800 Subject: blk-mq: fix elevator depth_updated method Current depth_updated has some problems: 1) depth_updated() will be called for each hctx, while all elevators will update async_depth for the disk level, this is not related to hctx; 2) In blk_mq_update_nr_requests(), if previous hctx update succeed and this hctx update failed, q->nr_requests will not be updated, while async_depth is already updated with new nr_reqeuests in previous depth_updated(); 3) All elevators are using q->nr_requests to calculate async_depth now, however, q->nr_requests is still the old value when depth_updated() is called from blk_mq_update_nr_requests(); Those problems are first from error path, then mq-deadline, and recently for bfq and kyber, fix those problems by: - pass in request_queue instead of hctx; - move depth_updated() after q->nr_requests is updated in blk_mq_update_nr_requests(); - add depth_updated() call inside init_sched() method to initialize async_depth; - remove init_hctx() method for mq-deadline and bfq that is useless now; Fixes: 77f1e0a52d26 ("bfq: update internal depth state when queue depth changes") Fixes: 39823b47bbd4 ("block/mq-deadline: Fix the tag reservation code") Fixes: 42e6c6ce03fd ("lib/sbitmap: convert shallow_depth from one word to the whole sbitmap") Signed-off-by: Yu Kuai Reviewed-by: Hannes Reinecke Reviewed-by: Li Nan Reviewed-by: Nilay Shroff Link: https://lore.kernel.org/r/20250821060612.1729939-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe --- block/elevator.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/elevator.h') diff --git a/block/elevator.h b/block/elevator.h index adc5c157e17e..c4d20155065e 100644 --- a/block/elevator.h +++ b/block/elevator.h @@ -37,7 +37,7 @@ struct elevator_mq_ops { void (*exit_sched)(struct elevator_queue *); int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int); void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int); - void (*depth_updated)(struct blk_mq_hw_ctx *); + void (*depth_updated)(struct request_queue *); bool (*allow_merge)(struct request_queue *, struct request *, struct bio *); bool (*bio_merge)(struct request_queue *, struct bio *, unsigned int); -- cgit v1.2.3