From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 147022222B6; Mon, 8 Sep 2025 06:24:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312697; cv=none; b=ssR09aXIFbXp/jbtqIzplq0EMwJXYhkAWUeRZbE49tg3T6jCHu1aXXWxP07MM3KWpdms58FB4qM7L+wNqUiWQodwz02TrKW9ZIig0wdV6Kr2/fY60MkZIcgQdG364JlV6WUyWUrhziEmNsUxr/6ydTfv34PibqtNea5a1RZHotM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312697; c=relaxed/simple; bh=8oYUvGC6wX9Iiy7ea2U0oxPOZ4z8fV4YueFX3XnHVk0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jYVcByT82r2pww05YIjUEPKJmDlLfr5TMk9OOoNcZgBux0eY2cwUzUin2MV8qwf1iepnjh/T/oMIU/rRE4GhOk8LG6VmvoNfT4w/7sFT+aWklCPRQBvCHUKpcDhYwRcuYf+JaJ6bqqC2HgdkPLAo6n2Zag4PoZuG5OnBGrxLX/Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cKxks5clbzYQv07; Mon, 8 Sep 2025 14:24:53 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 4724B1A0AE2; Mon, 8 Sep 2025 14:24:52 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S5; Mon, 08 Sep 2025 14:24:52 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 01/10] blk-mq: remove useless checking in queue_requests_store() Date: Mon, 8 Sep 2025 14:15:24 +0800 Message-Id: <20250908061533.3062917-2-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S5 X-Coremail-Antispam: 1UD129KBjvdXoW7JrWxurW3KF13Aw47ZFy8Grg_yoWxtFg_GF yUKr9FqFsakr4xZr47Ar10qF4xCw4rJF45WFWDJas5AFyfJas3K3y8Xr1rAr47ua9rGa1r Gw1xG34xCF40vjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbkxFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUGwA2048vs2IY02 0Ec7CjxVAFwI0_JFI_Gr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04 v7MxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j 6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7 AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE 2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcV C2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2Kfnx nUUI43ZEXa7VUbn2-7UUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai blk_mq_queue_attr_visible() already checked queue_is_mq(), no need to check this again in queue_requests_store(). Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-sysfs.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index c94b8b6ab024..1ffa65feca4f 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -69,9 +69,6 @@ queue_requests_store(struct gendisk *disk, const char *pa= ge, size_t count) unsigned int memflags; struct request_queue *q =3D disk->queue; =20 - if (!queue_is_mq(q)) - return -EINVAL; - ret =3D queue_var_store(&nr, page, count); if (ret < 0) return ret; --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 146994A21; Mon, 8 Sep 2025 06:24:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312697; cv=none; b=Goo+DEZe5hVQdM4KJ17tZPzrMkjOD22QdFk9cZu0aQ/hHy48wGvQK2e3Q/KQsOPH0AU/Ls5v96j7Tvk+n9SHGLm8dXRNvm8+yWTPi0GxtQMuFdAcoBW0LLP9Pxqlg9PBTVxDJlGvjrA2lkaXNG47L2VRCr3pLE6MwBfhM1UkUZM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312697; c=relaxed/simple; bh=OPMPvWdePNHvtOptZOETQLCk6zLujuh5OBkvtrtBbqo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=CJVZsIRIercKIDTP4m6K5ZkrgdmBxPgm4ylRPJFy/Bb1nxHatqhM3jCl9mz1ClgDgA6cu+FbtQR9b7k9b+L6LIatx/iRaPuf+oL0eBAXRVIJ6iEGrhGRe4sS73nbvzkuqwxncMb2IEMc/zuEiCrHN7zM3pyse840dRUJz7Us5b0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cKxkt1jBwzYQvL4; Mon, 8 Sep 2025 14:24:54 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id B3B091A0B82; Mon, 8 Sep 2025 14:24:52 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S6; Mon, 08 Sep 2025 14:24:52 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 02/10] blk-mq: remove useless checkings in blk_mq_update_nr_requests() Date: Mon, 8 Sep 2025 14:15:25 +0800 Message-Id: <20250908061533.3062917-3-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S6 X-Coremail-Antispam: 1UD129KBjvdXoWrtw13XF4fZrW8XFyrtw17trb_yoWDKrg_uF y0kFn2qws5tr4fZw4qka1YyF18Gw1kJF4fWa4Dtr9rXr1kCFnxXrWDKr15WFsrW3yxC3Wx uw1UWw43Jw4SvjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbkxFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXwA2048vs2IY02 0Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xv wVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM2 8EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AI xVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20x vE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xv r2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04 v7MxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j 6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7 AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE 2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcV C2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2Kfnx nUUI43ZEXa7VUj5Ef7UUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai 1) queue_requests_store() is the only caller of blk_mq_update_nr_requests(), where queue is already freezed, no need to check mq_freeze_depth; 2) q->tag_set must be set for request based device, and queue_is_mq() is already checked in blk_mq_queue_attr_visible(), no need to check q->tag_set. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 9055cd624700..0fac0236a5dc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4921,21 +4921,14 @@ int blk_mq_update_nr_requests(struct request_queue = *q, unsigned int nr) { struct blk_mq_tag_set *set =3D q->tag_set; struct blk_mq_hw_ctx *hctx; - int ret; + int ret =3D 0; unsigned long i; =20 - if (WARN_ON_ONCE(!q->mq_freeze_depth)) - return -EINVAL; - - if (!set) - return -EINVAL; - if (q->nr_requests =3D=3D nr) return 0; =20 blk_mq_quiesce_queue(q); =20 - ret =3D 0; queue_for_each_hw_ctx(q, hctx, i) { if (!hctx->tags) continue; --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 6ACBD22D780; 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dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4cKxks0NxLzKHMxf; Mon, 8 Sep 2025 14:24:53 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 2792E1A0FC1; Mon, 8 Sep 2025 14:24:53 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S7; Mon, 08 Sep 2025 14:24:52 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 03/10] blk-mq: check invalid nr_requests in queue_requests_store() Date: Mon, 8 Sep 2025 14:15:26 +0800 Message-Id: <20250908061533.3062917-4-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S7 X-Coremail-Antispam: 1UD129KBjvJXoWxCF4ruw1rXr45Kr17urWfXwb_yoWrWFWkpF W3Ka12k34Fqr10vFWIyay7Jw1Skws5Kr1xGFsaqa4Yvr1jkr4xXF1Fqry8XrW0yrWkCF47 Ar4DtrW5JF1kGrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUm014x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JrWl82xGYIkIc2 x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kIc2 xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWU JVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67 kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY 6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0x vEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVj vjDU0xZFpf9x0JUHWlkUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai queue_requests_store() is the only caller of blk_mq_update_nr_requests(), and blk_mq_update_nr_requests() is the only caller of blk_mq_tag_update_depth(), however, they all have checkings for nr_requests input by user. Make code cleaner by moving all the checkings to the top function: 1) nr_requests > reserved tags; 2) if there is elevator, 4 <=3D nr_requests <=3D 2048; 3) if elevator is none, 4 <=3D nr_requests <=3D tag_set->queue_depth; Meanwhile, case 2 is the only case tags can grow and -ENOMEM might be returned. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq-tag.c | 16 +--------------- block/blk-mq.c | 8 ++------ block/blk-mq.h | 2 +- block/blk-sysfs.c | 13 +++++++++++++ 4 files changed, 17 insertions(+), 22 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 5cffa5668d0c..725210f27471 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -584,14 +584,10 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) } =20 int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tagsptr, unsigned int tdepth, - bool can_grow) + struct blk_mq_tags **tagsptr, unsigned int tdepth) { struct blk_mq_tags *tags =3D *tagsptr; =20 - if (tdepth <=3D tags->nr_reserved_tags) - return -EINVAL; - /* * If we are allowed to grow beyond the original size, allocate * a new set of tags before freeing the old one. @@ -600,16 +596,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, struct blk_mq_tag_set *set =3D hctx->queue->tag_set; struct blk_mq_tags *new; =20 - if (!can_grow) - return -EINVAL; - - /* - * We need some sort of upper limit, set it high enough that - * no valid use cases should require more. - */ - if (tdepth > MAX_SCHED_RQ) - return -EINVAL; - /* * Only the sbitmap needs resizing since we allocated the max * initially. diff --git a/block/blk-mq.c b/block/blk-mq.c index 0fac0236a5dc..d7540b8e7471 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4924,9 +4924,6 @@ int blk_mq_update_nr_requests(struct request_queue *q= , unsigned int nr) int ret =3D 0; unsigned long i; =20 - if (q->nr_requests =3D=3D nr) - return 0; - blk_mq_quiesce_queue(q); =20 queue_for_each_hw_ctx(q, hctx, i) { @@ -4938,10 +4935,9 @@ int blk_mq_update_nr_requests(struct request_queue *= q, unsigned int nr) */ if (hctx->sched_tags) { ret =3D blk_mq_tag_update_depth(hctx, &hctx->sched_tags, - nr, true); + nr); } else { - ret =3D blk_mq_tag_update_depth(hctx, &hctx->tags, nr, - false); + ret =3D blk_mq_tag_update_depth(hctx, &hctx->tags, nr); } if (ret) goto out; diff --git a/block/blk-mq.h b/block/blk-mq.h index affb2e14b56e..2b3ade60c90b 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -171,7 +171,7 @@ void blk_mq_put_tag(struct blk_mq_tags *tags, struct bl= k_mq_ctx *ctx, unsigned int tag); void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags= ); int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tags, unsigned int depth, bool can_grow); + struct blk_mq_tags **tags, unsigned int depth); void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set, unsigned int size); void blk_mq_tag_update_sched_shared_tags(struct request_queue *q); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 1ffa65feca4f..f99519f7a820 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -75,12 +75,25 @@ queue_requests_store(struct gendisk *disk, const char *= page, size_t count) =20 memflags =3D blk_mq_freeze_queue(q); mutex_lock(&q->elevator_lock); + + if (nr =3D=3D q->nr_requests) + goto unlock; + if (nr < BLKDEV_MIN_RQ) nr =3D BLKDEV_MIN_RQ; 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charset="utf-8" From: Yu Kuai request_queue->nr_requests can be changed by: a) switching elevator by update nr_hw_queues b) switching elevator by elevator sysfs attribute c) configue queue sysfs attribute nr_requests Current lock order is: 1) update_nr_hwq_lock, case a,b 2) freeze_queue 3) elevator_lock, cas a,b,c And update nr_requests is seriablized by elevator_lock() already, however, in the case c), we'll have to allocate new sched_tags if nr_requests grow, and do this with elevator_lock held and queue freezed has the risk of deadlock. Hence use update_nr_hwq_lock instead, make it possible to allocate memory if tags grow, meanwhile also prevent nr_requests to be changed concurrently. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-sysfs.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index f99519f7a820..7ea15bf68b4b 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -68,13 +68,14 @@ queue_requests_store(struct gendisk *disk, const char *= page, size_t count) int ret, err; unsigned int memflags; struct request_queue *q =3D disk->queue; + struct blk_mq_tag_set *set =3D q->tag_set; =20 ret =3D queue_var_store(&nr, page, count); if (ret < 0) return ret; =20 - memflags =3D blk_mq_freeze_queue(q); - mutex_lock(&q->elevator_lock); + /* serialize updating nr_requests with switching elevator */ + down_write(&set->update_nr_hwq_lock); =20 if (nr =3D=3D q->nr_requests) goto unlock; @@ -89,13 +90,18 @@ queue_requests_store(struct gendisk *disk, const char *= page, size_t count) goto unlock; } =20 + memflags =3D blk_mq_freeze_queue(q); + mutex_lock(&q->elevator_lock); + err =3D blk_mq_update_nr_requests(disk->queue, nr); 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Mon, 08 Sep 2025 14:24:53 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 05/10] blk-mq: cleanup shared tags case in blk_mq_update_nr_requests() Date: Mon, 8 Sep 2025 14:15:28 +0800 Message-Id: <20250908061533.3062917-6-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S9 X-Coremail-Antispam: 1UD129KBjvJXoWxAr18ZFWDZryUAFWUtFWDurg_yoW5Jw1rpF Waka13K3sYqr12vFWav39xXw4Ygrsagr1SkrsxtryFqr12kF4xGr4rWrn5XFW8trZ5AFsI vF4DJFWUXr18W37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai For shared tags case, all hctx->shared_tags/tags are the same, it doesn't make sense to call into blk_mq_tag_update_depth() multiple times for the same tags. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq-tag.c | 7 ------- block/blk-mq.c | 43 ++++++++++++++++++++++--------------------- 2 files changed, 22 insertions(+), 28 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 725210f27471..aed84c5d5c2b 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -596,13 +596,6 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, struct blk_mq_tag_set *set =3D hctx->queue->tag_set; struct blk_mq_tags *new; =20 - /* - * Only the sbitmap needs resizing since we allocated the max - * initially. - */ - if (blk_mq_is_shared_tags(set->flags)) - return 0; - new =3D blk_mq_alloc_map_and_rqs(set, hctx->queue_num, tdepth); if (!new) return -ENOMEM; diff --git a/block/blk-mq.c b/block/blk-mq.c index d7540b8e7471..1ff6370f7314 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4926,34 +4926,35 @@ int blk_mq_update_nr_requests(struct request_queue = *q, unsigned int nr) =20 blk_mq_quiesce_queue(q); =20 - queue_for_each_hw_ctx(q, hctx, i) { - if (!hctx->tags) - continue; - /* - * If we're using an MQ scheduler, just update the scheduler - * queue depth. This is similar to what the old code would do. - */ - if (hctx->sched_tags) { - ret =3D blk_mq_tag_update_depth(hctx, &hctx->sched_tags, - nr); - } else { - ret =3D blk_mq_tag_update_depth(hctx, &hctx->tags, nr); - } - if (ret) - goto out; - } - - q->nr_requests =3D nr; - if (q->elevator && q->elevator->type->ops.depth_updated) - q->elevator->type->ops.depth_updated(q); - if (blk_mq_is_shared_tags(set->flags)) { if (q->elevator) blk_mq_tag_update_sched_shared_tags(q); else blk_mq_tag_resize_shared_tags(set, nr); + } else { + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->tags) + continue; + /* + * If we're using an MQ scheduler, just update the + * scheduler queue depth. This is similar to what the + * old code would do. + */ + if (hctx->sched_tags) + ret =3D blk_mq_tag_update_depth(hctx, + &hctx->sched_tags, nr); + else + ret =3D blk_mq_tag_update_depth(hctx, + &hctx->tags, nr); + if (ret) + goto out; + } } =20 + q->nr_requests =3D nr; + if (q->elevator && q->elevator->type->ops.depth_updated) + q->elevator->type->ops.depth_updated(q); + out: blk_mq_unquiesce_queue(q); =20 --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 55F98205AB6; Mon, 8 Sep 2025 06:24:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312698; cv=none; b=TwDutLM2negLauurqlbayJ10spUd8OQ4MIn9swCHwWxqE3LJ3QDWPM5iFYQJtwn31Gckse747cZkMB2rQiT/28cAcdqOQub5xdf5G3Dk8zGBbZp6kFNYHg2Ey/Bi9aO6f4KUCOkgTyC8aiA2gZtsqz6AKE+G9pnEZ1cqzeNVwMk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757312698; c=relaxed/simple; bh=mDZ3JD4XHVeayc9Xq8+hmEkFkkUXiSHZRZP49atSPdE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=UI/NtKMHlR0/3ZXBIThi1DqWS8+M2rRq/nAo1qgx9h2QHW0c1oiw92j2JX1fDRHf1Bv6ycteaCKGKZcqD1s7qbpvsOj8F3Qbc5GWY/P1rFb8ps31qvKcjpKxLg6GTlI4/q2RYoohKPqiXA65FYoDELIxExgtkXf6jw7OvM/S6g0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cKxkv71PSzYQvLn; Mon, 8 Sep 2025 14:24:55 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 75D621A1360; Mon, 8 Sep 2025 14:24:54 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S10; Mon, 08 Sep 2025 14:24:54 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 06/10] blk-mq: split bitmap grow and resize case in blk_mq_update_nr_requests() Date: Mon, 8 Sep 2025 14:15:29 +0800 Message-Id: <20250908061533.3062917-7-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S10 X-Coremail-Antispam: 1UD129KBjvJXoW7ZrWkXF18Ww4rJw4fGrW3ZFb_yoW8Xw4fpF Waga1ak3sYqr15ZFWIq34DX3Z0gFs3tF1ftr4xtFyFgr10gr4agr4Igr9xXFy8trZ5C3yS krs8tryvyr1UXrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai No functional changes are intended, make code cleaner and prepare to fix the grow case in following patches. Signed-off-by: Yu Kuai --- block/blk-mq.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 1ff6370f7314..82fa81036115 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4931,21 +4931,25 @@ int blk_mq_update_nr_requests(struct request_queue = *q, unsigned int nr) blk_mq_tag_update_sched_shared_tags(q); else blk_mq_tag_resize_shared_tags(set, nr); - } else { + } else if (!q->elevator) { queue_for_each_hw_ctx(q, hctx, i) { if (!hctx->tags) continue; - /* - * If we're using an MQ scheduler, just update the - * scheduler queue depth. This is similar to what the - * old code would do. - */ - if (hctx->sched_tags) - ret =3D blk_mq_tag_update_depth(hctx, - &hctx->sched_tags, nr); - else - ret =3D blk_mq_tag_update_depth(hctx, - &hctx->tags, nr); + sbitmap_queue_resize(&hctx->tags->bitmap_tags, + nr - hctx->tags->nr_reserved_tags); + } + } else if (nr <=3D q->elevator->et->nr_requests) { + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->sched_tags) + continue; + sbitmap_queue_resize(&hctx->sched_tags->bitmap_tags, + nr - hctx->sched_tags->nr_reserved_tags); + } + } else { + queue_for_each_hw_ctx(q, hctx, i) { + if (!hctx->sched_tags) + continue; + blk_mq_tag_update_depth(hctx, &hctx->sched_tags, nr); if (ret) goto out; } --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 6AB581A262A; Mon, 8 Sep 2025 06:40:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757313657; cv=none; b=itH4L6kjrr+LrJgA+ydfYU26r9kUA395bbzNYM6L1O+0rNszaHfNYyvlm/hEmnyy1ugkdVcon/1IljtjUlZOX1/yeCa5tOsz/Exfzy4MUBDWCgik0fLq0V6M3Kn9abP3iixXq6UUfdfERDtQKvx2/PuM2/JFxRde0QjWLN9ua8M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757313657; c=relaxed/simple; bh=por5FVkETrw0t+twqGZClVMpdCkS3aLmnlAefWWwm/k=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jEa4BG8pFo41VfgthJEzpqaLvGuN5dg5hBHnH4Z/JRsvgK4KqMaqqP2/dVMvYTTVOpNKFJ51NJr7bus765SMslSlzWPDiiOrFvHgvPgQUztjQALzQII1ifqswGHOQfLx4Zf/E8NHqsY519UKm4o/IKtm1oPZQnQMYx/c49mUOVo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4cKxkt5gdgzKHMxf; Mon, 8 Sep 2025 14:24:54 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id DEC181A1B4C; Mon, 8 Sep 2025 14:24:54 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S11; Mon, 08 Sep 2025 14:24:54 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 07/10] blk-mq-sched: add new parameter nr_requests in blk_mq_alloc_sched_tags() Date: Mon, 8 Sep 2025 14:15:30 +0800 Message-Id: <20250908061533.3062917-8-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S11 X-Coremail-Antispam: 1UD129KBjvJXoWxJw1kXF1rWryftFWrZryDGFg_yoWrGr4fpF 45XanFk34Yqr1kXay2yw4xXr13tws29FyxGr4ft34Fyr1q9rs3XF10gr47XrW0yrZ3AFsF yr1Dtay5WrsFg3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai This helper only support to allocate the default number of requests, add a new parameter to support specific number of requests. Prepare to fix potential deadlock in the case nr_requests grow. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq-sched.c | 14 +++++--------- block/blk-mq-sched.h | 2 +- block/blk-mq.h | 11 +++++++++++ block/elevator.c | 3 ++- 4 files changed, 19 insertions(+), 11 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index e2ce4a28e6c9..d06bb137a743 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -454,7 +454,7 @@ void blk_mq_free_sched_tags_batch(struct xarray *et_tab= le, } =20 struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, - unsigned int nr_hw_queues) + unsigned int nr_hw_queues, unsigned int nr_requests) { unsigned int nr_tags; int i; @@ -470,13 +470,8 @@ struct elevator_tags *blk_mq_alloc_sched_tags(struct b= lk_mq_tag_set *set, nr_tags * sizeof(struct blk_mq_tags *), gfp); if (!et) return NULL; - /* - * Default to double of smaller one between hw queue_depth and - * 128, since we don't split into sync/async like the old code - * did. Additionally, this is a per-hw queue depth. - */ - et->nr_requests =3D 2 * min_t(unsigned int, set->queue_depth, - BLKDEV_DEFAULT_RQ); + + et->nr_requests =3D nr_requests; et->nr_hw_queues =3D nr_hw_queues; =20 if (blk_mq_is_shared_tags(set->flags)) { @@ -521,7 +516,8 @@ int blk_mq_alloc_sched_tags_batch(struct xarray *et_tab= le, * concurrently. */ if (q->elevator) { - et =3D blk_mq_alloc_sched_tags(set, nr_hw_queues); + et =3D blk_mq_alloc_sched_tags(set, nr_hw_queues, + blk_mq_default_nr_requests(set)); if (!et) goto out_unwind; if (xa_insert(et_table, q->id, et, gfp)) diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index fe83187f41db..8e21a6b1415d 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -24,7 +24,7 @@ void blk_mq_exit_sched(struct request_queue *q, struct el= evator_queue *e); void blk_mq_sched_free_rqs(struct request_queue *q); =20 struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, - unsigned int nr_hw_queues); + unsigned int nr_hw_queues, unsigned int nr_requests); int blk_mq_alloc_sched_tags_batch(struct xarray *et_table, struct blk_mq_tag_set *set, unsigned int nr_hw_queues); void blk_mq_free_sched_tags(struct elevator_tags *et, diff --git a/block/blk-mq.h b/block/blk-mq.h index 2b3ade60c90b..731f4578d9a8 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -109,6 +109,17 @@ static inline struct blk_mq_hw_ctx *blk_mq_map_queue(b= lk_opf_t opf, return ctx->hctxs[blk_mq_get_hctx_type(opf)]; } =20 +/* + * Default to double of smaller one between hw queue_depth and + * 128, since we don't split into sync/async like the old code + * did. Additionally, this is a per-hw queue depth. + */ +static inline unsigned int blk_mq_default_nr_requests( + struct blk_mq_tag_set *set) +{ + return 2 * min_t(unsigned int, set->queue_depth, BLKDEV_DEFAULT_RQ); +} + /* * sysfs helpers */ diff --git a/block/elevator.c b/block/elevator.c index fe96c6f4753c..e2ebfbf107b3 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -669,7 +669,8 @@ static int elevator_change(struct request_queue *q, str= uct elv_change_ctx *ctx) lockdep_assert_held(&set->update_nr_hwq_lock); =20 if (strncmp(ctx->name, "none", 4)) { - ctx->et =3D blk_mq_alloc_sched_tags(set, set->nr_hw_queues); + ctx->et =3D blk_mq_alloc_sched_tags(set, set->nr_hw_queues, + blk_mq_default_nr_requests(set)); if (!ctx->et) return -ENOMEM; } --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 1B721239E7F; 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dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4cKxky67F3zYQvMn; Mon, 8 Sep 2025 14:24:58 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 595511A1C46; Mon, 8 Sep 2025 14:24:57 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S12; Mon, 08 Sep 2025 14:24:55 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 08/10] blk-mq: fix potential deadlock while nr_requests grown Date: Mon, 8 Sep 2025 14:15:31 +0800 Message-Id: <20250908061533.3062917-9-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S12 X-Coremail-Antispam: 1UD129KBjvJXoWxAF13uFWkZrW7JFykCw1Utrb_yoWrAFW3pF W5Ja12k3ySqr18XrW8Aw47XwnxKws2gr1xGrWSy34S9rnrKrs7Z3W8GFy8XrW0yrWkCFsr Ar4DJrZ8uF97W37anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai Allocate and free sched_tags while queue is freezed can deadlock[1], this is a long term problem, hence allocate memory before freezing queue and free memory after queue is unfreezed. [1] https://lore.kernel.org/all/0659ea8d-a463-47c8-9180-43c719e106eb@linux.= ibm.com/ Fixes: e3a2b3f931f5 ("blk-mq: allow changing of queue depth through sysfs") Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq.c | 22 ++++++++++------------ block/blk-mq.h | 5 ++++- block/blk-sysfs.c | 25 +++++++++++++++++-------- 3 files changed, 31 insertions(+), 21 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 82fa81036115..d85afbb9f031 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4917,11 +4917,13 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) } EXPORT_SYMBOL(blk_mq_free_tag_set); =20 -int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) +struct elevator_tags *blk_mq_update_nr_requests(struct request_queue *q, + struct elevator_tags *et, + unsigned int nr) { struct blk_mq_tag_set *set =3D q->tag_set; + struct elevator_tags *old_et =3D NULL; struct blk_mq_hw_ctx *hctx; - int ret =3D 0; unsigned long i; =20 blk_mq_quiesce_queue(q); @@ -4946,23 +4948,19 @@ int blk_mq_update_nr_requests(struct request_queue = *q, unsigned int nr) nr - hctx->sched_tags->nr_reserved_tags); } } else { - queue_for_each_hw_ctx(q, hctx, i) { - if (!hctx->sched_tags) - continue; - blk_mq_tag_update_depth(hctx, &hctx->sched_tags, nr); - if (ret) - goto out; - } + queue_for_each_hw_ctx(q, hctx, i) + hctx->sched_tags =3D et->tags[i]; + + old_et =3D q->elevator->et; + q->elevator->et =3D et; } =20 q->nr_requests =3D nr; if (q->elevator && q->elevator->type->ops.depth_updated) q->elevator->type->ops.depth_updated(q); =20 -out: blk_mq_unquiesce_queue(q); - - return ret; + return old_et; } =20 /* diff --git a/block/blk-mq.h b/block/blk-mq.h index 731f4578d9a8..6c9d03625ba1 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -6,6 +6,7 @@ #include "blk-stat.h" =20 struct blk_mq_tag_set; +struct elevator_tags; =20 struct blk_mq_ctxs { struct kobject kobj; @@ -45,7 +46,9 @@ void blk_mq_submit_bio(struct bio *bio); int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_b= atch *iob, unsigned int flags); void blk_mq_exit_queue(struct request_queue *q); -int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr); +struct elevator_tags *blk_mq_update_nr_requests(struct request_queue *q, + struct elevator_tags *tags, + unsigned int nr); void blk_mq_wake_waiters(struct request_queue *q); bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head = *, bool); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 7ea15bf68b4b..a0a7ebad378f 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -64,11 +64,12 @@ static ssize_t queue_requests_show(struct gendisk *disk= , char *page) static ssize_t queue_requests_store(struct gendisk *disk, const char *page, size_t count) { - unsigned long nr; - int ret, err; - unsigned int memflags; struct request_queue *q =3D disk->queue; struct blk_mq_tag_set *set =3D q->tag_set; + struct elevator_tags *et =3D NULL; + unsigned int memflags; + unsigned long nr; + int ret; =20 ret =3D queue_var_store(&nr, page, count); if (ret < 0) @@ -90,16 +91,24 @@ queue_requests_store(struct gendisk *disk, const char *= page, size_t count) goto unlock; } =20 + if (q->elevator && nr > q->elevator->et->nr_requests) { + /* allocate memory before freezing queue to prevent deadlock */ + et =3D blk_mq_alloc_sched_tags(set, q->nr_hw_queues, nr); + if (!et) { + ret =3D -ENOMEM; + goto unlock; + } + } + memflags =3D blk_mq_freeze_queue(q); mutex_lock(&q->elevator_lock); - - err =3D blk_mq_update_nr_requests(disk->queue, nr); - if (err) - ret =3D err; - + et =3D blk_mq_update_nr_requests(q, et, nr); mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); =20 + if (et) + blk_mq_free_sched_tags(et, set); + unlock: up_write(&set->update_nr_hwq_lock); return ret; --=20 2.39.2 From nobody Fri Oct 3 02:16:59 2025 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 6ABE71D5CD1; Mon, 8 Sep 2025 06:40:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4cKxkx51FPzKHN3F; Mon, 8 Sep 2025 14:24:57 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id C423D1A1005; Mon, 8 Sep 2025 14:24:57 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S13; Mon, 08 Sep 2025 14:24:57 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 09/10] blk-mq: remove blk_mq_tag_update_depth() Date: Mon, 8 Sep 2025 14:15:32 +0800 Message-Id: <20250908061533.3062917-10-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S13 X-Coremail-Antispam: 1UD129KBjvJXoW7Ar4xtF15Zr1xWr1rtryxKrg_yoW8trW5pF W3Ja1DK3yYqr1q9FWDtay7Aw1Fgw4vgr18Ka9aq34Fqr1jkr4xXF1kXr1kA3y0yrWkCr43 ArWqgryrJF1DJrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUma14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCw CI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsG vfC2KfnxnUUI43ZEXa7VUbPC7UUUUUU== X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai This helper is not used now. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- block/blk-mq-tag.c | 32 -------------------------------- block/blk-mq.h | 2 -- 2 files changed, 34 deletions(-) diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index aed84c5d5c2b..cbb93a653cef 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -583,38 +583,6 @@ void blk_mq_free_tags(struct blk_mq_tags *tags) kfree(tags); } =20 -int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tagsptr, unsigned int tdepth) -{ - struct blk_mq_tags *tags =3D *tagsptr; - - /* - * If we are allowed to grow beyond the original size, allocate - * a new set of tags before freeing the old one. - */ - if (tdepth > tags->nr_tags) { - struct blk_mq_tag_set *set =3D hctx->queue->tag_set; - struct blk_mq_tags *new; - - new =3D blk_mq_alloc_map_and_rqs(set, hctx->queue_num, tdepth); - if (!new) - return -ENOMEM; - - blk_mq_free_map_and_rqs(set, *tagsptr, hctx->queue_num); - hctx->queue->elevator->et->tags[hctx->queue_num] =3D new; - *tagsptr =3D new; - } else { - /* - * Don't need (or can't) update reserved tags here, they - * remain static and should never need resizing. - */ - sbitmap_queue_resize(&tags->bitmap_tags, - tdepth - tags->nr_reserved_tags); - } - - return 0; -} - void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set, unsigned in= t size) { struct blk_mq_tags *tags =3D set->shared_tags; diff --git a/block/blk-mq.h b/block/blk-mq.h index 6c9d03625ba1..af09eb617d11 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -184,8 +184,6 @@ unsigned long blk_mq_get_tags(struct blk_mq_alloc_data = *data, int nr_tags, void blk_mq_put_tag(struct blk_mq_tags *tags, struct blk_mq_ctx *ctx, unsigned int tag); void blk_mq_put_tags(struct blk_mq_tags *tags, int *tag_array, int nr_tags= ); -int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, - struct blk_mq_tags **tags, unsigned int depth); void blk_mq_tag_resize_shared_tags(struct blk_mq_tag_set *set, unsigned int size); void blk_mq_tag_update_sched_shared_tags(struct request_queue *q); 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smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4cKxky12KNzKHN4Q; Mon, 8 Sep 2025 14:24:58 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 3BDA41A10EC; Mon, 8 Sep 2025 14:24:58 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.104.67]) by APP4 (Coremail) with SMTP id gCh0CgD3QY6xdr5oCGEjBw--.62066S14; Mon, 08 Sep 2025 14:24:58 +0800 (CST) From: Yu Kuai To: nilay@linux.ibm.com, ming.lei@redhat.com, axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com, yangerkun@huawei.com, johnny.chenyi@huawei.com Subject: [PATCH for-6.18/block 10/10] blk-mq: fix stale nr_requests documentation Date: Mon, 8 Sep 2025 14:15:33 +0800 Message-Id: <20250908061533.3062917-11-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20250908061533.3062917-1-yukuai1@huaweicloud.com> References: <20250908061533.3062917-1-yukuai1@huaweicloud.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 X-CM-TRANSID: gCh0CgD3QY6xdr5oCGEjBw--.62066S14 X-Coremail-Antispam: 1UD129KBjvJXoW7KFWDCryfKr15Zw1xKFWfZrb_yoW8Xw1Dp3 yft39Fgwn5Zw18Wr10yay8tF13Aa95Aw43Jr4DKF1rtr98Awn29Fs2qr1rXF4xZrZ7AFWU urZ29r98Aa1qva7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmS14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkE bVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67 AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI 42IY6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF 4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBI daVFxhVjvjDU0xZFpf9x0JUQFxUUUUUU= X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Content-Type: text/plain; charset="utf-8" From: Yu Kuai The nr_requests documentation is still the removed single queue, remove it and update to current blk-mq. Signed-off-by: Yu Kuai Reviewed-by: Nilay Shroff --- Documentation/ABI/stable/sysfs-block | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stabl= e/sysfs-block index 0ddffc9133d0..0ed10aeff86b 100644 --- a/Documentation/ABI/stable/sysfs-block +++ b/Documentation/ABI/stable/sysfs-block @@ -603,16 +603,10 @@ Date: July 2003 Contact: linux-block@vger.kernel.org Description: [RW] This controls how many requests may be allocated in the - block layer for read or write requests. Note that the total - allocated number may be twice this amount, since it applies only - to reads or writes (not the accumulated sum). - - To avoid priority inversion through request starvation, a - request queue maintains a separate request pool per each cgroup - when CONFIG_BLK_CGROUP is enabled, and this parameter applies to - each such per-block-cgroup request pool. IOW, if there are N - block cgroups, each request queue may have up to N request - pools, each independently regulated by nr_requests. + block layer. Noted this value only represents the quantity for a + single blk_mq_tags instance. The actual number for the entire + device depends on the hardware queue count, whether elevator is + enabled, and whether tags are shared. =20 =20 What: /sys/block//queue/nr_zones --=20 2.39.2