From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261528AbVGDS16 (ORCPT ); Mon, 4 Jul 2005 14:27:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261524AbVGDS16 (ORCPT ); Mon, 4 Jul 2005 14:27:58 -0400 Received: from linuxwireless.org.ve.carpathiahost.net ([66.117.45.234]:52396 "EHLO linuxwireless.org.ve.carpathiahost.net") by vger.kernel.org with ESMTP id S261566AbVGDSYt (ORCPT ); Mon, 4 Jul 2005 14:24:49 -0400 Message-ID: <42C970D1.3090609@linuxwireless.org> Date: Mon, 04 Jul 2005 12:24:33 -0500 From: Alejandro Bonilla User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050513 Debian/1.7.8-1 X-Accept-Language: en MIME-Version: 1.0 To: Jens Axboe CC: Shawn Starr , Lenz Grimmer , Jesper Juhl , Dave Hansen , Henrik Brix Andersen , hdaps-devel@lists.sourceforge.net, LKML List Subject: Re: IBM HDAPS things are looking up References: <20050704061713.GA1444@suse.de> <20050704142723.2202.qmail@web88009.mail.re2.yahoo.com> <20050704144634.GQ1444@suse.de> In-Reply-To: <20050704144634.GQ1444@suse.de> 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 Jens Axboe wrote: > >That's madness, we can't add a kernel thread for every single little >silly thing. You don't need to stop any io, you just want to make sure >that your park request gets issued right after the current io has >finished. > > HI, For me, the heads have to park so fast. That I would be afraid of a kernel panil or something that could happen if you park the head so fast that it won't even tell the kernel it did, or because ext3 couldn't update or any crazy reason. I use a lot a project called laptop_mode, which suspend the hd until you do a request to the kernel or the HD and it spins up the HD. I think somehow, the kernel is not fast enough to do what we want, I mean, I don't see it. Imagine you are in starbucks, your laptop is over a 1.2 M table, Linus just said that a new kernel is out. So you simply download it, and now you are compiling it. But, you invited your kid to Starbucks. And while your CPU is at 100% and full throttle HD usage. Then your kid trips on the cable or simply pushes the PC out. Do you think that the kernel will STOP, HOLD and park the head in less than a second? OR on the time we need? I would say is a dammed good kernel if it would. (could RTOS, make things faster) Simply send the flames my way if you think I'm totally wrong. Which I might be. I really don't know... .Alejandro