From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753188AbdDJX6A (ORCPT ); Mon, 10 Apr 2017 19:58:00 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:57636 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751648AbdDJX56 (ORCPT ); Mon, 10 Apr 2017 19:57:58 -0400 Message-ID: <1491868675.2473.22.camel@HansenPartnership.com> Subject: Re: Race to power off harming SATA SSDs From: James Bottomley To: Tejun Heo , Henrique de Moraes Holschuh Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, Hans de Goede Date: Mon, 10 Apr 2017 16:57:55 -0700 In-Reply-To: <20170410235206.GA28603@wtj.duckdns.org> References: <20170410232118.GA4816@khazad-dum.debian.net> <20170410235206.GA28603@wtj.duckdns.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2017-04-11 at 08:52 +0900, Tejun Heo wrote: [...] > > Any comments? Any clues on how to make the delay "smarter" to > > trigger only once during platform shutdown, but still trigger per > > -device when doing per-device hotswapping ? > > So, if this is actually an issue, sure, we can try to work around; > however, can we first confirm that this has any other consequences > than a SMART counter being bumped up? I'm not sure how meaningful > that is in itself. Seconded; especially as the proposed patch is way too invasive: we run single threaded on shutdown and making every disk wait 1s is going to drive enterprises crazy. I'm with Tejun: If the device replies GOOD to SYNCHRONIZE CACHE, that means we're entitled to assume all written data is safely on non-volatile media and any "essential housekeeping" can be redone if the power goes away. James