From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261437AbUL2W4H (ORCPT ); Wed, 29 Dec 2004 17:56:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261436AbUL2W4G (ORCPT ); Wed, 29 Dec 2004 17:56:06 -0500 Received: from mail16.syd.optusnet.com.au ([211.29.132.197]:26344 "EHLO mail16.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S261437AbUL2WzB (ORCPT ); Wed, 29 Dec 2004 17:55:01 -0500 Message-ID: <41D33603.9060501@kolivas.org> Date: Thu, 30 Dec 2004 09:56:03 +1100 From: Con Kolivas User-Agent: Mozilla Thunderbird 1.0 (X11/20041206) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Paolo Ciarrocchi Cc: Maciej Soltysiak , linux-kernel@vger.kernel.org Subject: Re: Trying out SCHED_BATCH References: <41CD51E6.1070105@kolivas.org> <04ef01c4ede2$ff4a7cc0$0e25fe0a@pysiak> <41D31373.1090801@kolivas.org> <4d8e3fd304122914466b42c632@mail.gmail.com> In-Reply-To: <4d8e3fd304122914466b42c632@mail.gmail.com> 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 Paolo Ciarrocchi wrote: > On Thu, 30 Dec 2004 07:28:35 +1100, Con Kolivas wrote: > >>Maciej Soltysiak wrote: >> >>>Hi >>> >>>Con wrote: >>> >>> >>>>Only the staircase scheduler currently has an implementation of >>>>sched_batch and you need 2 more patches on top of the staircase patch >>>>for it to work. >>> >>>Hmm, Is it feasable to write a sched_batch policy for the current linux >>>schedulers? >> >>Yes. >> >>The proper way to make a sched_batch implementation is more >>comprehensive than what is made for staircase to prevent a deadlock >>based on a batch task getting an important lock in the kernel and not >>being able to release it due to a sched_normal task being higher >>priority than it that is actually trying to get the lock. There is code >>in the staircase version to prevent this from happening but probably not >>complete enough in design to prevent everything. However it works and I >>haven't had any reports of lockups since I implemented the extra checking. >> >>Would you like me to create a version like that? I don't have the time >>to try and make a more comprehensive solution and follow the debugging >>of such a beast. >> >> >>>I mean, if there are people that want it bad, maybe it would be nice to >>>be able >>>to use a version of sched_batch that would work without the staircase >>>scheduler. >>>It is still experimental, right? >> >>No it's not experimental. It is very stable and used in production systems. > > > Are you gointo to push to Linus/Andrew ? Staircase? I'm still in pain from the last time I tried to push it in a more palatable form via the plugsched architecture which took me a long time to do. I don't have the fortitude to go through that again in a hurry. Cheers, Con