From owner-freebsd-performance@FreeBSD.ORG Fri Nov 19 00:35:28 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 97DBE1065673 for ; Fri, 19 Nov 2010 00:35:28 +0000 (UTC) (envelope-from onemda@gmail.com) Received: from mail-wy0-f182.google.com (mail-wy0-f182.google.com [74.125.82.182]) by mx1.freebsd.org (Postfix) with ESMTP id 2C0658FC0A for ; Fri, 19 Nov 2010 00:35:27 +0000 (UTC) Received: by wyb35 with SMTP id 35so3065287wyb.13 for ; Thu, 18 Nov 2010 16:35:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type; bh=I1SiLxkyEUtVIDzOHSFXQDWIuwtVGBwbn0xo4qGU+oA=; b=WLoEBOXZJLA0zLvphfqUr7R7VSf3M37mG3qqbA8GcdlHOQ5YzlXHN8OpVvOwl7Imw/ rvk4m8bV8L9dtXfBfnMRF6KVbsHkBORgL552zZxlAEhdD1ztpvTxmtqFmtv653FDepqy TioEqvdFwzTb+YRegPrrW9y98Ak0h8NSUI9qg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=Ffj/WED8pmupiXTHG+PI+mXDFGBOuhAIMW0efLvqTpQx4zbh3Et6oMXdaP4dh+kRfC gmUP7WxmHYgnCumED40nAt+hdfFV56xBrsYQnoGGDx5laVPB4SgbKQqsC/n33AHnUYR8 bQVgEQ0RWlcQkWk33XzoTH54z/kKHvYeihKqE= Received: by 10.216.238.130 with SMTP id a2mr232254wer.77.1290125107416; Thu, 18 Nov 2010 16:05:07 -0800 (PST) MIME-Version: 1.0 Received: by 10.216.234.82 with HTTP; Thu, 18 Nov 2010 16:04:47 -0800 (PST) In-Reply-To: References: <4CE50849.106@zedat.fu-berlin.de> <4CE52177.3020306@freebsd.org> <20101118201644.00004c3c@unknown> From: Paul B Mahol Date: Fri, 19 Nov 2010 00:04:47 +0000 Message-ID: To: Lucius Windschuh Content-Type: text/plain; charset=ISO-8859-1 Cc: Bruce Cran , 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: Fri, 19 Nov 2010 00:35:28 -0000 On Thu, Nov 18, 2010 at 11:23 PM, Lucius Windschuh wrote: > 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* OT: Compare building kernel on tmpfs vs ufs on mdX vs ufs on usb stick and guess what is faster and does not cause non interactive mouse movement.