From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261691AbULFXbV (ORCPT ); Mon, 6 Dec 2004 18:31:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261703AbULFXbU (ORCPT ); Mon, 6 Dec 2004 18:31:20 -0500 Received: from mail.aei.ca ([206.123.6.14]:11717 "EHLO aeimail.aei.ca") by vger.kernel.org with ESMTP id S261700AbULFXan (ORCPT ); Mon, 6 Dec 2004 18:30:43 -0500 From: Ed Tomlinson Organization: me To: Jens Axboe Subject: Re: [PATCH] Time sliced CFQ #3 Date: Mon, 6 Dec 2004 18:30:33 -0500 User-Agent: KMail/1.7.1 Cc: Linux Kernel References: <20041204104921.GC10449@suse.de> <41B45134.4040005@gmx.de> <20041206132749.GX10498@suse.de> In-Reply-To: <20041206132749.GX10498@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200412061830.33418.edt@aei.ca> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens, This works here. Hope you keep patching against mainline. I`ve decided to track it till 2.6.10 comes out... Thanks, Ed On Monday 06 December 2004 08:27, Jens Axboe wrote: > On Mon, Dec 06 2004, Prakash K. Cheemplavam wrote: > > Jens Axboe schrieb: > > >On Mon, Dec 06 2004, Prakash K. Cheemplavam wrote: > > > > > >>Hi, > > >> > > >>this one crapped out on me, while having heavy disk activity. (updating > > >>gentoo portage tree - rebuilding metadata of it). Unfortunately I > > >>couldn't save the oops, as I had no hd access anymore and X would freeze > > >>a little later...(and I don't want to risk my data a second time...) > > > > > > > > >Did you save anything at all? Just the function of the EIP would be > > >better than nothing. > > > > Nope, sorry. I hoped it would be in the logs, but it seems as new cfq > > went havoc, hd access went dead. And I was a bit too nervous about my > > data so that I didn't write it down by hand... > > It is really rare for the io scheduler to cause serious data screwups, > thankfully. Often what will happen is that it will crash, but with > everything written fine up to that point. So it's similar to a power > loss, but the drive should get it's cache out on its own. > > > >Well hard to say anything qualified without an oops :/ > > > > > >I'll try with PREEMPT here. > > > > If you are not able to reproduce, I will try it again on a spare > > partition... Should access to zip drive stil be possible if hd's > > io-scheduler is dead? > > Depends on where it died, really. But the chances are probably slim. > > If you feel like giving it another go, I've uploaded a new patch here: > > http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3/cfq-time-slices-6.gz > > Changes: > > - Increase async_rq slice significantly (from 8 to 128) > > - Fix accounting bug that prevented non-fs requests from working > correctly. Things like cdrecord and cdda rippers would hang. > > - Add logic to check whether a given process is potentially runnable or > not. We don't arm the slice idle timer if the process has exited or is > not either running or about to be running. > > - TCQ fix: don't idle drive until last request comes in. > > - Fix a stall with exiting task holding the active queue. This should > fix Helges problems, I hope. > > - Restore ->nr_requests on io scheduler switch > > - Kill ->pid from io_context, this seems to have been added with 'as' > but never used by anyone. > >