From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267922AbUHKDqV (ORCPT ); Tue, 10 Aug 2004 23:46:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267921AbUHKDqV (ORCPT ); Tue, 10 Aug 2004 23:46:21 -0400 Received: from gizmo09bw.bigpond.com ([144.140.70.19]:40160 "HELO gizmo09bw.bigpond.com") by vger.kernel.org with SMTP id S267923AbUHKDqJ (ORCPT ); Tue, 10 Aug 2004 23:46:09 -0400 Message-ID: <4119967D.3060705@bigpond.net.au> Date: Wed, 11 Aug 2004 13:46:05 +1000 From: Peter Williams User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Con Kolivas CC: spaminos-ker@yahoo.com, William Lee Irwin III , linux-kernel@vger.kernel.org Subject: Re: Scheduler fairness problem on 2.6 series (Attn: Nick Piggin and others) References: <20040811010116.GL11200@holomorphy.com> <20040811022143.4892.qmail@web13910.mail.yahoo.com> <20040811022345.GN11200@holomorphy.com> <41198859.7050807@bigpond.net.au> <411988DF.9010308@bigpond.net.au> <41199129.9080809@bigpond.net.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Con Kolivas wrote: > Peter Williams writes: > >> Peter Williams wrote: >> >>> Peter Williams wrote: >>> >>>> William Lee Irwin III wrote: >>>> >>>>> On Tue, Aug 10, 2004 at 07:21:43PM -0700, spaminos-ker@yahoo.com >>>>> wrote: >>>>> >>>>>> I am not very familiar with all the parameters, so I just kept the >>>>>> defaults >>>>>> Anything else I could try? >>>>>> Nicolas >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> No. It appeared that the SPA bits had sufficient fairness in them to >>>>> pass this test but apparently not quite enough. >>>>> >>>> >>>> The interactive bonus may interfere with fairness (the throughput >>>> bonus should actually help it for tasks with equal nice) so you >>>> could try setting max_ia_bonus to zero (and possibly increasing >>>> max_tpt_bonus). With "eb" mode this should still give good >>>> interactive response but expect interactive response to suffer a >>>> little in "pb" mode however renicing the X server to a negative >>>> value should help. >>> >>> >>> >>> I should also have mentioned that fiddling with the promotion >>> interval may help. >> >> >> Having reread your original e-mail I think that this problem is >> probably being caused by the interactive bonus mechanism classifying >> the httpd server threads as "interactive" threads and giving them a >> bonus. But for some reason the daemon is not identified as >> "interactive" meaning that it gets given a lower priority. In this >> situation if there's a large number of httpd threads (even with >> promotion) it could take quite a while for the daemon to get a look >> in. Without promotion total starvation is even a possibility. >> >> Peter >> PS For both "eb" and "pb" modes, max_io_bonus should be set to zero on >> servers (where interactive responsiveness isn't an issue). >> PPS For "sc" mode, try setting "interactive" to zero and "compute" to 1. > > > No, compute should not be set to 1 for a server. It is reserved only for > computational nodes, not regular servers. "Compute" will increase > latency which is undersirable. Sorry, my misunderstanding. Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce