From nobody Tue Dec 2 01:51:04 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 399B4296BBD; Fri, 21 Nov 2025 05:29:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763702955; cv=none; b=WkCtLILSMKIhTRzAACoqoIVbIUaw0z7G1Fx2x2MDNfzvzqHkRz0w3bLdyYNLj0u8z2WFH7Pj9odmPIP576VTjnC8NCI7xg7g0eO0vjJ3jygW5BcTjMBloedsIKYTKTj3zYIDDwRYHAiFbcYxFpFO8w0UD/ZiZdQDACeqz1kLgak= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763702955; c=relaxed/simple; bh=N+a3FwIQ5mSv51OIK5gStmnCljmasX2MsHpVoRqxvm0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=agKnuoB/pmrE6PvNaZjDscrPrOWeaU9ORtqMcPd4Wlb7WlpLqAv3CdbczeErl7vG2ap8HV438xmoF2TYNfp8l6VzHsAHp2fEMKhtynVPfYJLdK0hgzF4GA8ZkcquSAJDcX6EFMdo4T+7MmysMIWfxLEo5H6OJ2gmcaZlKiEvGo8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id D0A6AC116D0; Fri, 21 Nov 2025 05:29:12 +0000 (UTC) From: Yu Kuai To: axboe@kernel.dk, nilay@linux.ibm.com, bvanassche@acm.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: yukuai@fnnas.com Subject: [PATCH v6 4/8] blk-mq: add a new queue sysfs attribute async_depth Date: Fri, 21 Nov 2025 13:28:51 +0800 Message-ID: <20251121052901.1341976-5-yukuai@fnnas.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251121052901.1341976-1-yukuai@fnnas.com> References: <20251121052901.1341976-1-yukuai@fnnas.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a new field async_depth to request_queue and related APIs, this is currently not used, following patches will convert elevators to use this instead of internal async_depth. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-core.c | 1 + block/blk-mq.c | 6 ++++++ block/blk-sysfs.c | 42 ++++++++++++++++++++++++++++++++++++++++++ block/elevator.c | 1 + include/linux/blkdev.h | 1 + 5 files changed, 51 insertions(+) diff --git a/block/blk-core.c b/block/blk-core.c index 14ae73eebe0d..cc5c9ced8e6f 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -463,6 +463,7 @@ struct request_queue *blk_alloc_queue(struct queue_limi= ts *lim, int node_id) fs_reclaim_release(GFP_KERNEL); =20 q->nr_requests =3D BLKDEV_DEFAULT_RQ; + q->async_depth =3D BLKDEV_DEFAULT_RQ; =20 return q; =20 diff --git a/block/blk-mq.c b/block/blk-mq.c index 6c505ebfab65..ae6ce68f4786 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4628,6 +4628,7 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set= *set, spin_lock_init(&q->requeue_lock); =20 q->nr_requests =3D set->queue_depth; + q->async_depth =3D set->queue_depth; =20 blk_mq_init_cpu_queues(q, set->nr_hw_queues); blk_mq_map_swqueue(q); @@ -4994,6 +4995,11 @@ struct elevator_tags *blk_mq_update_nr_requests(stru= ct request_queue *q, q->elevator->et =3D et; } =20 + /* + * Preserve relative value, both nr and async_depth are at most 16 bit + * value, no need to worry about overflow. + */ + q->async_depth =3D max(q->async_depth * nr / q->nr_requests, 1); q->nr_requests =3D nr; if (q->elevator && q->elevator->type->ops.depth_updated) q->elevator->type->ops.depth_updated(q); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 8684c57498cc..5c2d29ac6570 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -127,6 +127,46 @@ queue_requests_store(struct gendisk *disk, const char = *page, size_t count) return ret; } =20 +static ssize_t queue_async_depth_show(struct gendisk *disk, char *page) +{ + guard(mutex)(&disk->queue->elevator_lock); + + return queue_var_show(disk->queue->async_depth, page); +} + +static ssize_t +queue_async_depth_store(struct gendisk *disk, const char *page, size_t cou= nt) +{ + struct request_queue *q =3D disk->queue; + unsigned int memflags; + unsigned long nr; + int ret; + + if (!queue_is_mq(q)) + return -EINVAL; + + ret =3D queue_var_store(&nr, page, count); + if (ret < 0) + return ret; + + if (nr =3D=3D 0) + return -EINVAL; + + memflags =3D blk_mq_freeze_queue(q); + scoped_guard(mutex, &q->elevator_lock) { + if (q->elevator) { + q->async_depth =3D min(q->nr_requests, nr); + if (q->elevator->type->ops.depth_updated) + q->elevator->type->ops.depth_updated(q); + } else { + ret =3D -EINVAL; + } + } + blk_mq_unfreeze_queue(q, memflags); + + return ret; +} + static ssize_t queue_ra_show(struct gendisk *disk, char *page) { ssize_t ret; @@ -532,6 +572,7 @@ static struct queue_sysfs_entry _prefix##_entry =3D { \ } =20 QUEUE_RW_ENTRY(queue_requests, "nr_requests"); +QUEUE_RW_ENTRY(queue_async_depth, "async_depth"); QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb"); QUEUE_LIM_RW_ENTRY(queue_max_sectors, "max_sectors_kb"); QUEUE_LIM_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb"); @@ -754,6 +795,7 @@ static struct attribute *blk_mq_queue_attrs[] =3D { */ &elv_iosched_entry.attr, &queue_requests_entry.attr, + &queue_async_depth_entry.attr, #ifdef CONFIG_BLK_WBT &queue_wb_lat_entry.attr, #endif diff --git a/block/elevator.c b/block/elevator.c index 5b37ef44f52d..5ff21075a84a 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -589,6 +589,7 @@ static int elevator_switch(struct request_queue *q, str= uct elv_change_ctx *ctx) blk_queue_flag_clear(QUEUE_FLAG_SQ_SCHED, q); q->elevator =3D NULL; q->nr_requests =3D q->tag_set->queue_depth; + q->async_depth =3D q->tag_set->queue_depth; } blk_add_trace_msg(q, "elv switch: %s", ctx->name); =20 diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index cdc68c41fa96..edddf17f8304 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -552,6 +552,7 @@ struct request_queue { * queue settings */ unsigned int nr_requests; /* Max # of requests */ + unsigned int async_depth; /* Max # of async requests */ =20 #ifdef CONFIG_BLK_INLINE_ENCRYPTION struct blk_crypto_profile *crypto_profile; --=20 2.51.0