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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 D7A04C433E0 for ; Thu, 18 Jun 2020 12:31:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B061220707 for ; Thu, 18 Jun 2020 12:31:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=octiron.net header.i=@octiron.net header.b="UxoWk3h3"; dkim=pass (2048-bit key) header.d=octiron.net header.i=@octiron.net header.b="x8aZ/Cuc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727022AbgFRMb5 (ORCPT ); Thu, 18 Jun 2020 08:31:57 -0400 Received: from papylos.uuid.uk ([185.34.62.16]:39844 "EHLO papylos.uuid.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726982AbgFRMb4 (ORCPT ); Thu, 18 Jun 2020 08:31:56 -0400 X-Greylist: delayed 378 seconds by postgrey-1.27 at vger.kernel.org; Thu, 18 Jun 2020 08:31:55 EDT DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=octiron.net ; s=20180214; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: 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=B+4Gs/0j/CESrZMyfibpjnqye8gtYFkuSwBCEo4B4VU=; b=UxoWk3h38JdZskTb8k+g1JvlSX J5meE/UfbOPHdvXFp37nuu03bS2qMZvlCfKTubNavPntxMInBBDpGlIPj8dUY4cmIDi1swo1koauR WNrHn7VZYfILoctfwqGfoEolGDj9BGipBbCSLbYZiqXNIIc0Zj3xPJXIrmRuAvYOg0PM0KmgWpuhP 0SVZLXWj/QaIB3kVDfpgP2WvC1sJyRfK7TwBauFz+C6XoB2C2dEhH/k7+EcTSP+q8tbaV3tpkTp3F k+ZPRU7PxOaWQkJbtLZgXP06q+6RyK3hcStGxkT5U2cY2TWtACQq1A3BSWYe6Q75JFh2ra/zyfEIy rngaYrCQ==; Received: by papylos.uuid.uk with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jltbe-0002ue-PS; Thu, 18 Jun 2020 13:25:29 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=octiron.net ; s=20180214; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject; bh=B+4Gs/0j/CESrZMyfibpjnqye8gtYFkuSwBCEo4B4VU=; b=x8aZ/CucIHuoSAuaPxrBMUKSLr KJK8ZF8FACElj/AlLKrUtED2J1vemTCikrWSh5nFeyf/w7eK/i+WMGcflRSk+lHGQ/HMDG9inpQSR i1SS25kjnbQutg8MG2eIZI6NPVJu/3pR2/mNWe6cYfrG2UgQ3biYMkgvzo4vq2FpSXzhUA1eSX3la oRKtFhpHjFvr9kNkmn7ZOHharZILBuU7GfCnse+UrfxBj+Wpco/NBNSEAxTt3/FHk2QcTYbbu5XV5 TF4cVtmZFPK2Fjw9G2q1YRwN19VMFZ2B8Hd1TT7rDyJpOYLtd0vmy3Y2dCpjVBehw01Z20zo6b8P1 9zmrx4FA==; Received: by tsort.uuid.uk with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1jltba-0005r9-6N; Thu, 18 Jun 2020 13:25:18 +0100 Subject: Re: [PATCH] scsi: sd: stop SSD (non-rotational) disks before reboot To: Christoph Hellwig Cc: "James E.J. Bottomley" , "Martin K. Petersen" , Jonathan Corbet , Linux Kernel Mailing List , linux-scsi@vger.kernel.org, linux-doc@vger.kernel.org References: <499138c8-b6d5-ef4a-2780-4f750ed337d3@0882a8b5-c6c3-11e9-b005-00805fc181fe> <20200618072138.GA11778@infradead.org> From: Simon Arlott Message-ID: <9877e7de-d573-694b-2b75-95192756684b@0882a8b5-c6c3-11e9-b005-00805fc181fe> Date: Thu, 18 Jun 2020 13:25:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200618072138.GA11778@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 18/06/2020 08:21, Christoph Hellwig wrote: > On Wed, Jun 17, 2020 at 07:49:57PM +0100, Simon Arlott wrote: >> Avoiding a stop of the disk on a reboot is appropriate for HDDs because >> they're likely to continue to be powered (and should not be told to spin >> down only to spin up again) but the default behaviour for SSDs should >> be changed to stop them before the reboot. > > I don't think that is true in general. At least for most current server > class and older desktop and laptop class systems they use the same > format factors and enclosures, although they are slightly divering now. > > So I think this needs to be quirked based on the platform and/or > enclosure. Are you referring to the behaviour for handling HDDs or SSDs? For HDDs, the default "1" option could mean "automatic" and apply to rotational disks when power loss is expected. For SSDs, I don't think an extra stop should ever be an issue. -- Simon Arlott