Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270034AbTGLXxx (ORCPT ); Sat, 12 Jul 2003 19:53:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270036AbTGLXxx (ORCPT ); Sat, 12 Jul 2003 19:53:53 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:6382 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S270034AbTGLXxw (ORCPT ); Sat, 12 Jul 2003 19:53:52 -0400 Date: Sun, 13 Jul 2003 02:08:32 +0200 From: Jens Axboe To: Andrew Morton Cc: Dave Jones , mroos@linux.ee, linux-kernel@vger.kernel.org Subject: Re: 2.5 'what to expect' Message-ID: <20030713000832.GT843@suse.de> References: <20030711140219.GB16433@suse.de> <20030712202352.GA7741@suse.de> <20030712151511.107c1f59.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030712151511.107c1f59.akpm@osdl.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1844 Lines: 50 On Sat, Jul 12 2003, Andrew Morton wrote: > Dave Jones wrote: > > > > .. > > > > Something seems amiss. The deprecated elvtune interface is the old -r/-w/-b command line. > > I was lead to believe a new elvtune appeared which supports an option > > for changing the elevator under 2.5, however a quick google doesn't turn > > up any such patched elvtune, so I'm somewhat puzzled. > > No, we planned to do the selection via sysfs rather than ioctl. Right > > > Maybe just suggest the sysfs interface at once and not mention > > > elvtune? > > > > Changing the elevator type per device via sysfs does seem to make > > sense, however /sys/block//queue/iosched/ doesn't yield > > anything that would suggest this is possible (yet). I think Jens > > has patches for this? > > But it never happened. There are all sorts of nasties wrt actually Well the code exists. > making the switch. Some related to request queueing, some to sysfs > itself. I don't recall any request queueing problems, it's pretty straight forward to lock the queue down and prevent any new requests from entering. sysfs problems is the only issue, and before Al does his magic on that stuff, the patch just doesn't make sense. So it hasn't been posted publically. With the sysfs disabled, I can switch io schedulers on the fly quite easily. > So yes, we should have runtime selection, and maybe sometime we will, > but the lowness of the return-to-effort ratio means it won't happen > soon. Depends. If the sysfs stuff doesn't get fixed, then no it wont happen. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/