From nobody Sun Dec 28 15:37:35 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52FD7C4167B for ; Thu, 7 Dec 2023 04:33:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229751AbjLGEc7 (ORCPT ); Wed, 6 Dec 2023 23:32:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbjLGEc5 (ORCPT ); Wed, 6 Dec 2023 23:32:57 -0500 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01BBCD54 for ; Wed, 6 Dec 2023 20:33:03 -0800 (PST) Received: by mail-oi1-x234.google.com with SMTP id 5614622812f47-3b844357f7cso439747b6e.1 for ; Wed, 06 Dec 2023 20:33:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=smartx-com.20230601.gappssmtp.com; s=20230601; t=1701923582; x=1702528382; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=f/Lf0+IIfQE0io2nHdmDYhVLqD8zUaOijlO0hMGWTXo=; b=wT5VYrmQHNPb1qQ3+Ylr9AB94gfVkmZCFtEREN9DtQks6bAY4XrND3mEdttHR1wUFc iTMAjQlS3o3LvUrt8m1x0G1eUlxaF3TpDvc1sl6Iqnv8z3Q+K/pRmBXMRfRo4+yDjRGl ghcAxp3IzknCeqJbtDbB2MlB1RyGOM2LDvqOqWYvjd5uHkHxjkfAHdLuYfLhb8hWdMS5 MTaSlG6GHaZbIC04MgNmA1u1mJJSYnxM0tRpJ+3m8orCYnGracbeMtYooR1sH/1hbjEg at7BC0WM+rm9qm5t8GXilCu/mYYtKbpy7L6s3BCL1IFgBtZvYBRa7wovb16RpUfuvPUR ELPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701923582; x=1702528382; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=f/Lf0+IIfQE0io2nHdmDYhVLqD8zUaOijlO0hMGWTXo=; b=g9ac2S121q0/w9tZ02bvzRDjuynuYrXBnnODCi4bpXbTinSEuXm40uenoz6jmIldFU 8AIj6T5w+35TT/0tDAzoDyaC0PyfcNXGIqjWONuMkRobgcdNgSxG2NPT+IbxSWkgBD3v XmKO+u5A7XnGVwj9l2OfDqferxHgbM2eJ/L01Y4JXUJ3sKt0fZzEY7R28QUEY5BCB7mH r0xsLXvt+0WrAazfJhPSMBGSpVW70/ts8br9zPueIXsIf+iYUxeJaIG6oI7uC+INh+FS WKVPsgdkHh94zyr3UPhrw3WxaciN4HFXRYq2ztnr7Vc/BXkBYbpU7EXpRY9/cBm4eniS 6uaQ== X-Gm-Message-State: AOJu0YwBq18fq/C2I2v+vqK2sztWge3g3zMeVNnd+F2Wtf772C15If0A KxVraIufMR9ABPcxoNnoayet6w== X-Google-Smtp-Source: AGHT+IHJYbFIUTZB44VBOizgu6C4ZjGpZ8ov/2VlLfUy+pzKCRy95+hHpycf+1VuZxTdnNIi7xPU9A== X-Received: by 2002:aca:1b02:0:b0:3b9:dcf0:63b9 with SMTP id b2-20020aca1b02000000b003b9dcf063b9mr615047oib.23.1701923581661; Wed, 06 Dec 2023 20:33:01 -0800 (PST) Received: from localhost.localdomain.localdomain ([8.210.91.195]) by smtp.gmail.com with ESMTPSA id v19-20020aa78513000000b006cea1e12564sm332971pfn.81.2023.12.06.20.32.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Dec 2023 20:33:01 -0800 (PST) From: Li Feng To: Jens Axboe , "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Xuan Zhuo , linux-block@vger.kernel.org (open list:BLOCK LAYER), linux-kernel@vger.kernel.org (open list), virtualization@lists.linux.dev (open list:VIRTIO BLOCK AND SCSI DRIVERS) Cc: Li Feng Subject: [PATCH] virtio_blk: set the default scheduler to none Date: Thu, 7 Dec 2023 12:31:05 +0800 Message-ID: <20231207043118.118158-1-fengli@smartx.com> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" virtio-blk is generally used in cloud computing scenarios, where the performance of virtual disks is very important. The mq-deadline scheduler has a big performance drop compared to none with single queue. In my tests, mq-deadline 4k readread iops were 270k compared to 450k for none. So here the default scheduler of virtio-blk is set to "none". Signed-off-by: Li Feng Reviewed-by: Chaitanya Kulkarni --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index d53d6aa8ee69..5183ec8e00be 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1367,7 +1367,7 @@ static int virtblk_probe(struct virtio_device *vdev) vblk->tag_set.ops =3D &virtio_mq_ops; vblk->tag_set.queue_depth =3D queue_depth; vblk->tag_set.numa_node =3D NUMA_NO_NODE; - vblk->tag_set.flags =3D BLK_MQ_F_SHOULD_MERGE; + vblk->tag_set.flags =3D BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_NO_SCHED_BY_DEFA= ULT; vblk->tag_set.cmd_size =3D sizeof(struct virtblk_req) + sizeof(struct scatterlist) * VIRTIO_BLK_INLINE_SG_CNT; --=20 2.42.0