From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422969AbXDRMqz (ORCPT ); Wed, 18 Apr 2007 08:46:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422971AbXDRMqz (ORCPT ); Wed, 18 Apr 2007 08:46:55 -0400 Received: from nz-out-0506.google.com ([64.233.162.238]:48639 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422969AbXDRMqy (ORCPT ); Wed, 18 Apr 2007 08:46:54 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=sVuqNkfW8NyLuMRE3t6JxBc4OQ71/eNKwZK3OI5ZeDS4u6yd8r5Tix44sW1hq44T/ylwjIrI/FGD5naBqYMo3I4weAVO+D5kwbemJn3u2ss9wK7xf97lR9XdZ9A9OX7dGYn2nBjuyauDT/xdZkWzGlubFsEikDKchkm3U9yoIeE= Message-ID: <46261337.3010406@gmail.com> Date: Wed, 18 Apr 2007 21:46:47 +0900 From: Tejun Heo User-Agent: Icedove 1.5.0.10 (X11/20070307) MIME-Version: 1.0 To: Alan Cox CC: 7eggert@gmx.de, Chuck Ebbert , emisca , Jan Engelhardt , Bartlomiej Zolnierkiewicz , linux-kernel , linux-ide@vger.kernel.org, Adrian Bunk , Andrew Morton Subject: Re: Loud "pop" coming from hard drive on reboot References: <88SeR-5Sf-15@gated-at.bofh.it> <88Sov-662-3@gated-at.bofh.it> <88SHV-6uL-29@gated-at.bofh.it> <8agVk-3wc-81@gated-at.bofh.it> <8b3IR-4mE-25@gated-at.bofh.it> <8b3SA-4z3-5@gated-at.bofh.it> <8b42g-51N-15@gated-at.bofh.it> <8bbdm-7iS-27@gated-at.bofh.it> <46260981.1040109@gmail.com> <20070418132904.3322ba5f@the-village.bc.nu> In-Reply-To: <20070418132904.3322ba5f@the-village.bc.nu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: >> Not that simple. Most disks don't spin up on SYNCHRONIZE_CACHE if its >> cache is clean. Sadly some disks actually spin up when it receives spin >> down command while spun down to immediately spin down again, so we would >> be fixing problem for some number of disks while breaking others. :-( > > Snoop the last command sent to the drive, that tells you if you can skip > the cache flush ? Thought about that and querying power state before doing shutdown sequence but things get somewhat ugly because shutdown sequence is driven from sd->shutdown(). We'll have to snoop both sync and shutdown commands and check whether the system is shutting down. Also, I felt very uneasy about faking successful completion to SYNCHRONIZE_CACHE. I dunno. It's already too late for 2.6.21. I was hoping we could get distros to update shutdown utilities in not-too-distant future but I have no experience with that. Is that just a wishful thinking? -- tejun