From owner-freebsd-stable@FreeBSD.ORG Fri Dec 9 15:47:53 2011 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 D4A9F106566B for ; Fri, 9 Dec 2011 15:47:53 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-ww0-f50.google.com (mail-ww0-f50.google.com [74.125.82.50]) by mx1.freebsd.org (Postfix) with ESMTP id 6D6EE8FC19 for ; Fri, 9 Dec 2011 15:47:53 +0000 (UTC) Received: by wgbdr11 with SMTP id dr11so5852886wgb.31 for ; Fri, 09 Dec 2011 07:47:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=ogXdXT+OvIhyCSB/PywP7TtwzLuY1wGXTnrEmskfjAU=; b=DvpLcNIm5B6spah4YF/NP4QfrbYPccfo9iUOHtRpjw797b/wlxuMScf1sYd98pwREH E6Ra59U0CpsdVtvPAEgxuoDKlIqzbI+nqIhk5pqmfNWMdPMXD2Nc4kZV5nM30bi1V0HP nZV1u93jV/XZJKKRlbpxfU4WlyhPsE313Igio= MIME-Version: 1.0 Received: by 10.227.197.70 with SMTP id ej6mr7160545wbb.13.1323443853790; Fri, 09 Dec 2011 07:17:33 -0800 (PST) Sender: asmrookie@gmail.com Received: by 10.216.171.8 with HTTP; Fri, 9 Dec 2011 07:17:33 -0800 (PST) In-Reply-To: <4EE1EAFE.3070408@m5p.com> References: <4EE1EAFE.3070408@m5p.com> Date: Fri, 9 Dec 2011 16:17:33 +0100 X-Google-Sender-Auth: 3AGQ34j-sSlvf3WZJ8s7C0BIYaQ Message-ID: From: Attilio Rao To: George Mitchell Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-stable@freebsd.org Subject: Re: SCHED_ULE should not be the default 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: Fri, 09 Dec 2011 15:47:53 -0000 2011/12/9 George Mitchell : > dnetc is an open-source program from http://www.distributed.net/. =C2=A0I= t > tries a brute-force approach to cracking RC4 puzzles and also computes > optimal Golomb rulers. =C2=A0It starts up one process per CPU and runs at > nice 20 and is, for all intents and purposes, 100% compute bound. > > Here is what happens on my system, running 9.0-PRERELEASE, with and > without dnetc running, with SCHED_ULE and SCHED-4BSD, when I run the > command: > > time make buildkernel KERNCONF=3DWONDERLAND > > (I get similar results on 8.x as well.) > > SCHED_4BSD, dnetc not running: > 1329.715u 123.739s 24:47.95 97.6% =C2=A0 =C2=A0 =C2=A0 6310+1987k 11233+1= 1098io 419pf+0w > > SCHED_4BSD, dnetc running: > 1329.364u 115.158s 26:14.83 91.7% =C2=A0 =C2=A0 =C2=A0 6325+1987k 10912+1= 1060io 393pf+0w > > SCHED_ULE, dnetc not running: > 1357.457u 121.526s 25:20.64 97.2% =C2=A0 =C2=A0 =C2=A0 6326+1990k 11234+1= 1149io 419pf+0w > > SCHED_ULE, dnetc running: > Still going after seven and a half hours of clock time, up to > compiling netgraph/bluetooth. =C2=A0(Completed in another five minutes > after stopping dnetc so I could write this message in a reasonable > amount of time.) > > Not everybody runs this sort of program, but there are plenty of > similar projects out there, and people who try to participate in > them will be mightily displeased with their FreeBSD systems when > they do. =C2=A0Is there some case where SCHED_ULE exhibits significantly > better performance than SCHED_4BSD? =C2=A0If not, I think SCHED-4BSD > should remain the default GENERIC configuration until this is fixed. Hi George, are you interested in exploring more the case with SCHED_ULE and dnetc? More precisely I'd be interested in KTR traces. To be even more precise: With a completely stable GENERIC configuration (or otherwise please post your kernel config) please add the following: options KTR options KTR_ENTRIES=3D262144 options KTR_COMPILE=3D(KTR_SCHED) options KTR_MASK=3D(KTR_SCHED) While you are in the middle of the slow-down (so once it is well established) please do: # sysclt debug.ktr.cpumask=3D"" In the end go with: # ktrdump -ctf > ktr-ule-problem.out and send the file to this mailing list. Thanks, Attilio --=20 Peace can only be achieved by understanding - A. Einstein