From owner-freebsd-current@FreeBSD.ORG Mon Jun 1 08:30:22 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BC6571065678; Mon, 1 Jun 2009 08:30:22 +0000 (UTC) (envelope-from ohartman@mail.zedat.fu-berlin.de) Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) by mx1.freebsd.org (Postfix) with ESMTP id 47F358FC21; Mon, 1 Jun 2009 08:30:22 +0000 (UTC) (envelope-from ohartman@mail.zedat.fu-berlin.de) Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost1.zedat.fu-berlin.de (Exim 4.69) with esmtp (envelope-from ) id <1MB2uT-0004Og-BY>; Mon, 01 Jun 2009 10:30:21 +0200 Received: from e178015162.adsl.alicedsl.de ([85.178.15.162] helo=thor.walstatt.dyndns.org) by inpost2.zedat.fu-berlin.de (Exim 4.69) with esmtpsa (envelope-from ) id <1MB2uT-0002ra-8e>; Mon, 01 Jun 2009 10:30:21 +0200 Message-ID: <4A23919F.8050905@mail.zedat.fu-berlin.de> Date: Mon, 01 Jun 2009 10:30:23 +0200 From: "O. Hartmann" User-Agent: Thunderbird 2.0.0.21 (X11/20090410) MIME-Version: 1.0 To: Kip Macy References: <951233.95131.qm@web39108.mail.mud.yahoo.com> <3c1674c90905302055g542cfadarf201cc273639977d@mail.gmail.com> In-Reply-To: <3c1674c90905302055g542cfadarf201cc273639977d@mail.gmail.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Originating-IP: 85.178.15.162 X-Mailman-Approved-At: Mon, 01 Jun 2009 11:23:39 +0000 Cc: attilio@freebsd.org, bf , freebsd-current@freebsd.org Subject: Re: signifanctly slowdown of FreeBSD 8.0-CURRENT/amd64 X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Jun 2009 08:30:23 -0000 Kip Macy wrote: >> I'm running the r193133 amd64 with a custom kernel and all debugging off >> on an AMD Athlon64 3400+ single-core, and I haven't noticed any significant >> slowing, although I haven't been doing any systematic benchmarking. >> >> What would be the penalties of running an SMP -CURRENT kernel on >> single-core hardware with no hyperthreading? Can anyone quantify the >> typical added overhead? Or, counterintuitively, would an SMP kernel >> be better in some ways? >> >> > > He is trying to diagnose if the problem was introduced by enabling > adaptive spinning on sx locks. They're only enabled on SMP kernels. > > Cheers, > Kip > Well, no SMP on UP AMD CPUs without SMT means no usage of the sx locks. As far as I know, the sx locks were introduced a couple of days ago, weren't they? To avoid any kind of misunderstanding, there is no permanent 'slowdown', it occurs especially whenever the system's compiler builds world or a kernel or heavy I/O activities occur. It seems my boxes, especially the UP box, is freezing, no reaction on X11. Well, first time I thought it is related to UP, low memory or especially new drm code used with X11 for acceleration, but I also realized those 'slowdown-incidents' on boxes with multicores, 8 or more GB of RAM and no X11 installed and running. This performance impact in situations whenever building a world is significant. We did not change the compiler, it is still the old gcc 4.2, so I do not expect an impact from new high-memory and cpu-consuming optimization routines. I do not even benchmark my boxes day for day, but I usually do a set of the same work on those boxes used for scientific work, so while building world even on SMP boxes and working after installation with the same software set reveals some weirdness in some points. I thought this is due some use-uninterruptable debugging switches, some wrote the malloc code is about to change and so on so I was wondering if there is something temporarely going on at the moment where some hints could prevent me from building a world within this testing phase. Just speculation. Greetings, Oliver