From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267914AbUHKDb2 (ORCPT ); Tue, 10 Aug 2004 23:31:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267915AbUHKDb1 (ORCPT ); Tue, 10 Aug 2004 23:31:27 -0400 Received: from mail011.syd.optusnet.com.au ([211.29.132.65]:14285 "EHLO mail011.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S267914AbUHKDbZ (ORCPT ); Tue, 10 Aug 2004 23:31:25 -0400 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> Message-ID: X-Mailer: http://www.courier-mta.org/cone/ From: Con Kolivas To: Peter Williams 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) Date: Wed, 11 Aug 2004 13:31:16 +1000 Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="US-ASCII" Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. Cheers, Con