From owner-freebsd-current@FreeBSD.ORG Fri Aug 31 19:54:52 2007 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0704416A418 for ; Fri, 31 Aug 2007 19:54:52 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.bluestop.org (muon.bluestop.org [80.68.94.188]) by mx1.freebsd.org (Postfix) with ESMTP id 9AE8D13C45D for ; Fri, 31 Aug 2007 19:54:51 +0000 (UTC) (envelope-from bruce@cran.org.uk) Received: from muon.draftnet (dyn-62-56-105-44.dslaccess.co.uk [62.56.105.44]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by muon.bluestop.org (Postfix) with ESMTP id 986AA3000D for ; Fri, 31 Aug 2007 20:50:15 +0100 (BST) Message-ID: <46D8719A.1070109@cran.org.uk> Date: Fri, 31 Aug 2007 20:52:58 +0100 From: Bruce Cran User-Agent: Thunderbird 2.0.0.6 (X11/20070809) MIME-Version: 1.0 To: current@freebsd.org References: <46D83351.9000407@cran.org.uk> In-Reply-To: <46D83351.9000407@cran.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Subject: Re: High interrupt load on VIA C3 machine 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: Fri, 31 Aug 2007 19:54:52 -0000 Bruce Cran wrote: > I recently upgraded to 7-CURRENT on my VIA EPIA router, and have found > that there's a constant interrupt load of around 15%. My dmesg > reports the CPU as: > > CPU: VIA C3 Nehemiah+RNG+AES (533.36-MHz 686-class CPU) > Origin = "CentaurHauls" Id = 0x698 Stepping = 8 > > Features=0x381b93f > > real memory = 132055040 (125 MB) > avail memory = 119701504 (114 MB) > > uname -a: > FreeBSD router.draftnet 7.0-CURRENT FreeBSD 7.0-CURRENT #4: Fri Aug 31 > 07:04:22 BST 2007 > brucec@router.draftnet:/usr/obj/usr/src/sys/ROUTER i386 > > The first few lines of top -S are: > last pid: 1394; load averages: 0.08, 0.12, > 0.21 > up 0+01:59:10 16:13:59 > 57 processes: 3 running, 39 sleeping, 15 waiting > CPU states: 3.1% user, 0.0% nice, 4.8% system, 17.0% interrupt, > 75.1% idle > Mem: 7360K Active, 6116K Inact, 12M Wired, 48K Cache, 9504K Buf, 90M Free > Swap: 2048M Total, 2048M Free > > PID USERNAME THR PRI NICE SIZE RES STATE TIME WCPU COMMAND > 11 root 1 171 ki31 0K 8K RUN 100:01 81.98% idle > 12 root 1 -32 - 0K 8K WAIT 12:31 7.96% swi4: > clock sio > 1394 brucec 1 46 0 3512K 1744K RUN 0:01 4.98% top > 586 root 1 44 0 5016K 2516K RUN 2:39 0.00% ppp > 1044 root 1 44 0 3176K 980K select 0:51 0.00% powerd > 28 root 1 -68 - 0K 8K WAIT 0:45 0.00% irq11: > vr0 dc3 > 30 root 1 -68 - 0K 8K WAIT 0:32 0.00% irq12: dc1 > > While there's a high interrupt load, vmstat -i doesn't show anything > wrong: > > interrupt total rate > irq0: clk 718003 99 > irq4: sio0 897 0 > irq5: dc0 31 0 > irq8: rtc 919064 127 > irq10: dc2 uhci0+ 31 0 > irq11: vr0 dc3 63548 8 > irq12: dc1 62120 8 > irq14: ata0 1555 0 > irq15: ata1 581 0 > Total 1765830 245 > > I had thought of using hwpmc to find out what was happening, but > unfortunately VIA CPUs aren't supported yet. Is there another way I > can find out what's going on? This appears to be an issue with powerd/cpufreq - disabling powerd reduces the interrupt load to a couple of percent at most, and the clock interrupt task now only accumulates CPU time very slowly (previously it was using 7% CPU all the time). -- Bruce Cran