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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 E3F4BC3A5A2 for ; Tue, 3 Sep 2019 08:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2E5B21883 for ; Tue, 3 Sep 2019 08:57:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="CozME/+E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728454AbfICI5N (ORCPT ); Tue, 3 Sep 2019 04:57:13 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:38118 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725888AbfICI5N (ORCPT ); Tue, 3 Sep 2019 04:57:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=vhIsHUff9nU1D0d7I/0vbBMLDwIosKafjBP+GTnctBE=; b=CozME/+E09j/GSpLys/Hxsim9 Epi3cTXZ+yYNNzMBCGIHkkrxs9PxurM10jZAlhjq0I350SDEWumTKT7pHxM3XOS7+lWmzJ9YwVuQR jPNpX8bnyj3Mbv28ha9dZjGj9eLH6dccolqdaJW5crPxtU0vjJoLv5SJ1f7guIonlnLDvO0I61t17 233bLzWrRKiAKLZibgVlsTAB5RfLvk6sg8hPIFBowoxrk3HH27gIs1ugGX8jhpDyRZl+iwGg7UHQD PcL7FjSGSAN2mCYPsXlTxDoPUb8LJ+nw9wJRFLBk6r6iBcqJ0NQfWH+MtP3TxPUG1Iw0/mT4dIkRE YmPStPnlA==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1i54ci-0007nq-OA; Tue, 03 Sep 2019 08:57:12 +0000 Date: Tue, 3 Sep 2019 01:57:12 -0700 From: Christoph Hellwig To: Damien Le Moal Cc: linux-block@vger.kernel.org, Jens Axboe , linux-scsi@vger.kernel.org, "Martin K . Petersen" Subject: Re: [PATCH v2 4/7] block: Improve default elevator selection Message-ID: <20190903085712.GD23783@infradead.org> References: <20190828022947.23364-1-damien.lemoal@wdc.com> <20190828022947.23364-5-damien.lemoal@wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190828022947.23364-5-damien.lemoal@wdc.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Aug 28, 2019 at 11:29:44AM +0900, Damien Le Moal wrote: > For block devices that do not specify required features, preserve the > current default elevator selection (mq-deadline for single queue > devices, none for multi-queue devices). However, for devices specifying > required features (e.g. zoned block devices ELEVATOR_F_ZBD_SEQ_WRITE > feature), select the first available elevator providing the required > features. > > In all cases, default to "none" if no elevator is available or if the > initialization of the default elevator fails. > > Signed-off-by: Damien Le Moal Looks good, Reviewed-by: Christoph Hellwig