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 X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78CF9C433E1 for ; Mon, 1 Jun 2020 07:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA7520734 for ; Mon, 1 Jun 2020 07:50:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NQN6bqf/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726056AbgFAHuT (ORCPT ); Mon, 1 Jun 2020 03:50:19 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:27658 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725935AbgFAHuT (ORCPT ); Mon, 1 Jun 2020 03:50:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590997818; 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=IuO46ycNz8mneB+aXPJm85h+RFJWz/TY+HoUCs4wBY8=; b=NQN6bqf/niicZYal857+Jbw0LTOyT0X/vq0nBk/aMgJPRaBGb+tIXpGfMfnLXwf+DMyUVc jSP8pLGDDUKorZR/vi5IJUIL56uQO70POfwu5tCwOeq8MD6JpHSwJ4ObGk2e21xNeHHMlf qjk1NJP8rBF7z/uLmBDk3ZXW7kUg7tE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-167-5Kga0UcWNre1R3UidKM26A-1; Mon, 01 Jun 2020 03:50:13 -0400 X-MC-Unique: 5Kga0UcWNre1R3UidKM26A-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 42EB9100CCC2; Mon, 1 Jun 2020 07:50:12 +0000 (UTC) Received: from T590 (ovpn-13-152.pek2.redhat.com [10.72.13.152]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0A29C78EA8; Mon, 1 Jun 2020 07:50:01 +0000 (UTC) Date: Mon, 1 Jun 2020 15:49:57 +0800 From: Ming Lei To: Linus Walleij Cc: linux-block@vger.kernel.org, Jens Axboe , linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, Johannes Thumshirn , Christoph Hellwig , Damien Le Moal , Paolo Valente Subject: Re: [PATCH] block: Flag elevators suitable for single queue Message-ID: <20200601074957.GE1181806@T590> References: <20200528081003.238804-1-linus.walleij@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200528081003.238804-1-linus.walleij@linaro.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On Thu, May 28, 2020 at 10:10:03AM +0200, Linus Walleij wrote: > The Kyber block scheduler is not suitable for single hardware > queue devices, so add a new flag for single hardware queue > devices and add that to the deadline and BFQ schedulers > so the Kyber scheduler will not be selected for single queue > devices. The above may not be true for some single hw queue high performance HBA( such as megasas), which can get better performance from none, so it is reasonable to get better performance from kyber, see 6ce3dd6eec11 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'"), and the following link: https://lore.kernel.org/linux-block/20180710010331.27479-1-ming.lei@redhat.com/ Thanks, Ming