From mboxrd@z Thu Jan 1 00:00:00 1970 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 06908C4167B for ; Fri, 8 Dec 2023 02:00:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1573000AbjLHCAt (ORCPT ); Thu, 7 Dec 2023 21:00:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1572983AbjLHCAq (ORCPT ); Thu, 7 Dec 2023 21:00:46 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDAB610DD for ; Thu, 7 Dec 2023 18:00:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702000851; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JJ2EPKnJQm+fAlvkL+74UAK/7dPrJSHeWEZnkUKYj2w=; b=JJl6fOKUtPa+BEVQBIAoe4DrScWqVxJ29CNABz3oDmhW8ODg+19VtR7/Cq0JHoK5ZWtLEN tEbaLoExAUW+h/+hkIUrQ6MMLvBfMQcpOWG01+eb/DLQdfVVmAvi5OJcyhvUWNVjXrJTLM fqlUbMTnzIWbLalHceyoAyn3U2wYhbU= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-662-Fz9at8PFNQ-bnMhti6X8PQ-1; Thu, 07 Dec 2023 21:00:48 -0500 X-MC-Unique: Fz9at8PFNQ-bnMhti6X8PQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D6E0C3C10153; Fri, 8 Dec 2023 02:00:47 +0000 (UTC) Received: from fedora (unknown [10.72.120.10]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 991062026D66; Fri, 8 Dec 2023 02:00:41 +0000 (UTC) Date: Fri, 8 Dec 2023 10:00:36 +0800 From: Ming Lei To: Li Feng Cc: Jens Axboe , "Michael S. Tsirkin" , Jason Wang , Paolo Bonzini , Stefan Hajnoczi , Xuan Zhuo , "open list:BLOCK LAYER" , open list , "open list:VIRTIO BLOCK AND SCSI DRIVERS" Subject: Re: [PATCH] virtio_blk: set the default scheduler to none Message-ID: References: <20231207043118.118158-1-fengli@smartx.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231207043118.118158-1-fengli@smartx.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 07, 2023 at 12:31:05PM +0800, Li Feng wrote: > 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". The test result shows you may not test HDD. backing of virtio-blk. none can lose IO merge capability more or less, so probably sequential IO perf drops in case of HDD backing. Thanks, Ming