From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: Serial ATA (SATA) shutdown info Date: Thu, 17 May 2007 11:18:26 +0200 Message-ID: <464C1DE2.8080501@gmail.com> References: <1179232945.16527.25.camel@quest.netsplit.com> <711b967b0705150834sdd14538x459119386c19a7ac@mail.gmail.com> <1179243992.16527.56.camel@quest.netsplit.com> <464AE0EB.9080300@gmail.com> <1179317806.16527.73.camel@quest.netsplit.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from nz-out-0506.google.com ([64.233.162.225]:63687 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754078AbXEQJS5 (ORCPT ); Thu, 17 May 2007 05:18:57 -0400 Received: by nz-out-0506.google.com with SMTP id r28so882022nza for ; Thu, 17 May 2007 02:18:55 -0700 (PDT) In-Reply-To: <1179317806.16527.73.camel@quest.netsplit.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Scott James Remnant Cc: linux-ide@vger.kernel.org, 114683@bugs.launchpad.net Scott James Remnant wrote: > On Wed, 2007-05-16 at 12:46 +0200, Tejun Heo wrote: > >>> I'll keep an eye on the thread you linked to, if we don't even need to >>> write any zeros, we're definitely happy people :-) >> Me happy too. :-) >> > Out of interest, do you know there is a hysterical need to sync() before > one calls reboot()? > > I would have thought the kernel takes care of making sure it's own data > structures are flushed to disk anyway, but I can't see the reference in > the kernel code for where it might do this. I dunno. I seem to recall there was discussion about disk driver not flushing cache or something like that years ago but I could be imagining things. With recent kernels, there's no reason for userland to do that before shutting down. Kernel always flushes caches during shutdown, but we can also afford some paranoia there as that doesn't cause any harm. -- tejun