From owner-freebsd-performance@FreeBSD.ORG Thu Nov 18 23:23:09 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 81F1C1065674 for ; Thu, 18 Nov 2010 23:23:09 +0000 (UTC) (envelope-from lwindschuh@googlemail.com) Received: from mail-iw0-f182.google.com (mail-iw0-f182.google.com [209.85.214.182]) by mx1.freebsd.org (Postfix) with ESMTP id 3DB608FC15 for ; Thu, 18 Nov 2010 23:23:09 +0000 (UTC) Received: by iwn39 with SMTP id 39so4267271iwn.13 for ; Thu, 18 Nov 2010 15:23:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=JdL9K6Vb6tU/OGGx3Z/xAZNJ+29LV3aUp9ZLWM5xLYI=; b=mf5gCrQGIHU+4b6yLDpM7N+Tm6jn5o/884KmgXNYb7E4dFOl0HBf9FPvDOa06Z0a5B 1KjIIXdnXEagEnd6Lh4RIuldsFCX6/IamFHdB5KlCDvsMhKfB8bK5qfmcuNA6j92y6sw Qkxiw75GFc+rrHYMeN2BL/WdLyn5ZtnZJsZbo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=i9rzyOA+pUcZWxxbfGCk9dYj3zz2utelYum5elmva9wnzlyKeYDlzCpk9XC5R2c/q7 W0z1AdT4vpFtz3Pmg8YrC0vuDuqWHykYKHs8uXbDUdAOsa4PO0IZazxhgf3oiFXixQ8B a8FBxdSdRke+fkMf8ZXLyeOkKmME2lTbrID9g= MIME-Version: 1.0 Received: by 10.231.39.198 with SMTP id h6mr1529440ibe.21.1290122588650; Thu, 18 Nov 2010 15:23:08 -0800 (PST) Received: by 10.231.192.139 with HTTP; Thu, 18 Nov 2010 15:23:08 -0800 (PST) In-Reply-To: <20101118201644.00004c3c@unknown> References: <4CE50849.106@zedat.fu-berlin.de> <4CE52177.3020306@freebsd.org> <20101118201644.00004c3c@unknown> Date: Fri, 19 Nov 2010 00:23:08 +0100 Message-ID: From: Lucius Windschuh To: Bruce Cran Content-Type: text/plain; charset=ISO-8859-1 X-Mailman-Approved-At: Thu, 18 Nov 2010 23:31:17 +0000 Cc: freebsd-performance@freebsd.org Subject: Re: TTY task group scheduling X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Nov 2010 23:23:09 -0000 2010/11/18 Bruce Cran : >Have you tried increasing kern.sched.preempt_thresh? According to >http://groups.google.com/group/mailing.freebsd.stable/browse_thread/thread/05a39f816fd8acc6/82affa9f195b747d?lnk=raot&fwc=1&pli=1 >a good value for desktop use would be 224. Hmm, I though I tried this -- but this helps indeed. :-) The browser, movie player etc. behave much better when a "make -j4 buildworld" is running on my 2-core machine in the background. Thank you. 2010/11/18 Bruce Cran : > If you're using UFS, I've found it to be quite a bottleneck when > doing parallel IO: I even ran a "svn up" in one terminal and tried to > login on another a couple of days ago only to find the motd took over 5 > seconds to appear! That may be excessive since I was running a kernel > with WITNESS and INVARIANTS, but I've found ZFS to be far better if you > want good interactivity when reading/writing to disks. This is indeed another issue, which I also encountered, but explicitly left out since I don't blame the task scheduler for that. ;) Unfortunately, I don't know how much SCHED_ULE's inability to cope with more runnable threads than cores, as Steve mentioned, accounts to the problem I observe. Time to switch back to SCHED_4BSD? *sigh* Lucius