From owner-freebsd-stable@FreeBSD.ORG Thu Sep 30 06:11:27 2010 Return-Path: Delivered-To: stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6E759106567A; Thu, 30 Sep 2010 06:11:27 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 728AB8FC18; Thu, 30 Sep 2010 06:11:26 +0000 (UTC) Received: from porto.topspin.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id JAA11957; Thu, 30 Sep 2010 09:11:23 +0300 (EEST) (envelope-from avg@icyb.net.ua) Received: from localhost.topspin.kiev.ua ([127.0.0.1]) by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1P1CMV-0007Fz-3S; Thu, 30 Sep 2010 09:11:23 +0300 Message-ID: <4CA42A0A.6090003@icyb.net.ua> Date: Thu, 30 Sep 2010 09:11:22 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.9) Gecko/20100918 Lightning/1.0b2 Thunderbird/3.1.4 MIME-Version: 1.0 To: Don Lewis References: <201009292327.o8TNRTPa077418@gw.catspoiler.org> In-Reply-To: <201009292327.o8TNRTPa077418@gw.catspoiler.org> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: stable@FreeBSD.org, sterling@camdensoftware.com, freebsd@jdc.parodius.com Subject: Re: CPU time accounting broken on 8-STABLE machine after a few hours of uptime 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, 30 Sep 2010 06:11:27 -0000 on 30/09/2010 02:27 Don Lewis said the following: > On 29 Sep, Andriy Gapon wrote: >> on 29/09/2010 11:56 Don Lewis said the following: >>> I'm using the same kernel config as the one on a slower !SMP box which >>> I'm trying to squeeze as much performance out of as possible. My kernel >>> config file contains these statements: >>> nooptions SMP >>> nodevice apic >>> >>> Testing with an SMP kernel is on my TODO list. >> >> SMP or not, it's really weird to see apic disabled nowadays. > > I tried enabling apic and got worse results. I saw ping RTTs as high as > 67 seconds. Here's the timer info with apic enabled: I didn't expect anything to change in this output with APIC enabled. > # sysctl kern.timecounter > kern.timecounter.tick: 1 > kern.timecounter.choice: TSC(800) ACPI-fast(1000) i8254(0) dummy(-1000000) > kern.timecounter.hardware: ACPI-fast > kern.timecounter.stepwarnings: 0 > kern.timecounter.tc.i8254.mask: 65535 > kern.timecounter.tc.i8254.counter: 53633 > kern.timecounter.tc.i8254.frequency: 1193182 > kern.timecounter.tc.i8254.quality: 0 > kern.timecounter.tc.ACPI-fast.mask: 16777215 > kern.timecounter.tc.ACPI-fast.counter: 7988816 > kern.timecounter.tc.ACPI-fast.frequency: 3579545 > kern.timecounter.tc.ACPI-fast.quality: 1000 > kern.timecounter.tc.TSC.mask: 4294967295 > kern.timecounter.tc.TSC.counter: 1341917999 > kern.timecounter.tc.TSC.frequency: 2500014018 > kern.timecounter.tc.TSC.quality: 800 > kern.timecounter.invariant_tsc: 0 > > Here's the verbose boot info with apic: > vmstat -i ? > I've also experimented with SMP as well as SCHED_4BSD (all previous > testing was with !SMP and SCHED_ULE). I still see occasional problems > with SCHED_4BSD and !SMP, but so far I have not seen any problems with > SCHED_ULE and SMP. Good! > I did manage to catch the problem with lock profiling enabled: > > I'm currently testing SMP some more to verify if it really avoids this > problem. OK. -- Andriy Gapon