From owner-freebsd-stable@FreeBSD.ORG Thu Sep 2 10:46:17 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A15CA10656CB; Thu, 2 Sep 2010 10:46:17 +0000 (UTC) (envelope-from jan.grant@bristol.ac.uk) Received: from dirj.bris.ac.uk (dirj.bris.ac.uk [137.222.10.78]) by mx1.freebsd.org (Postfix) with ESMTP id 5EB3B8FC16; Thu, 2 Sep 2010 10:46:17 +0000 (UTC) Received: from mail.ilrt.bris.ac.uk ([137.222.16.62]) by dirj.bris.ac.uk with esmtp (Exim 4.69) (envelope-from ) id 1Or7J7-0003Cw-Am; Thu, 02 Sep 2010 11:46:16 +0100 Received: from cse-jg.cse.bris.ac.uk ([137.222.12.37]:61066) by mail.ilrt.bris.ac.uk with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.63) (envelope-from ) id 1Or7Iy-0006RD-DF; Thu, 02 Sep 2010 11:46:04 +0100 Date: Thu, 2 Sep 2010 11:46:04 +0100 (BST) From: jan.grant@bristol.ac.uk X-X-Sender: cmjg@tribble.ilrt.bris.ac.uk To: Andriy Gapon In-Reply-To: <4C7F7C0F.8080004@icyb.net.ua> Message-ID: References: <4C7F7C0F.8080004@icyb.net.ua> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-ILRT-MailScanner: Found to be clean X-ILRT-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-3.411, required 5, autolearn=not spam, ALL_TRUSTED -1.80, AWL 0.99, BAYES_00 -2.60) X-ILRT-MailScanner-From: jan.grant@bristol.ac.uk X-Spam-Status: No X-Spam-Score: -2.8 X-Spam-Level: -- Cc: freebsd-stable@freebsd.org, Ivan Voras Subject: Re: Tuning the scheduler? Desktop with a CPU-intensive task becomes rapidly unusable. X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Sep 2010 10:46:17 -0000 On Thu, 2 Sep 2010, Andriy Gapon wrote: > on 02/09/2010 12:08 jan.grant@bristol.ac.uk said the following: > > On Wed, 1 Sep 2010, Ivan Voras wrote: > > > >> On 09/01/10 15:08, jan.grant@bristol.ac.uk wrote: > >>> I'm running -STABLE with a kde-derived desktop. This setup (which is > >>> pretty standard) is providing abysmal interactive performance on an > >>> eight-core machine whenever I try to do anything CPU-intensive (such as > >>> building a port). > >>> > >>> Basically, trying to build anything from ports rapidly renders everything > >>> else so "non-interactive" in the eyes of the scheduler that, for instance, > >>> switching between virtual desktops (I have six of them in reasonably > >>> frequent use) takes about a minute of painful waiting on redraws to > >>> complete. > >> > >> Are you sure this is about the scheduler or maybe bad X11 drivers? > > > > Not 100%, but mostly convinced; I've just started looking at this. It's my > > first stab at what might be going on. X11 performance is usually pretty > > snappy. There's no paging pressure at all. > > From my experience: > 1. system with Athlon II X2 250 CPU and onboard AMD graphics - no issues with > interaction between buildworld and GUI with all KDE4 effects enabled (OpenGL). > 2. system with comparable Core2 Duo CPU and onboard Intel graphics (G33) - > enabling OpenGL desktop effects in KDE4 leads to the consequences like what you > describe. With all GUI bells and whistles disabled the system behaves quite > like the AMD system. All desktop effects are disabled. The graphics are from an nVidia GeForce 8500 GT (G86) with the X.org driver. (It's not _just_ desktop behaviour that's affected, though: the box runs a number of small headless [interactive] server processes which also appear to get rapidly starved of CPU time.) The behaviour isn't visible with the 4bsd scheduler; "stuff" generally remains snappy and responsive. I'll keep poking around and see if I can get to the bottom of it. -- jan grant, ISYS, University of Bristol. http://www.bris.ac.uk/ Tel +44 (0)117 3317661 http://ioctl.org/jan/ Rereleasing dolphins into the wild since 1998.