From owner-freebsd-arch@FreeBSD.ORG Mon Apr 6 20:38:29 2015 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 0FB07975; Mon, 6 Apr 2015 20:38:29 +0000 (UTC) Received: from mail-ig0-x236.google.com (mail-ig0-x236.google.com [IPv6:2607:f8b0:4001:c05::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C9313130; Mon, 6 Apr 2015 20:38:28 +0000 (UTC) Received: by igblo3 with SMTP id lo3so30763073igb.1; Mon, 06 Apr 2015 13:38:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=+NJ750icqisf56XHqN/ugpJj/xADn7OHiQ5472wc9TI=; b=tpEwcFMCgCVAsn9JhtJr+xCopCQBVCKESGfNSuJltt+lDiuODS1cdoiAtXImy7lvJR xIDpiWQ7aWG1Y/7lxngrDDsh/pQBUOJwahb+MjRe1eTJOtLcKflRgZfBmQjS2ammOK29 Yu1KCoPxrH2SUqeMxPxxr9cq3nwoArQPLt2gtBn2CSj2WAXewUluCNSAQS0dNiApcM0o Uep3Y4BjdqYcKxmf3sW3ZhgPePA+FEUtQgOJ1oAxJ/57vO7W2Wj4WoICCZPetkzBFZ+N EPYsFM2jYMGWyYk+KVLtbKXuGAZgl4cCmiQYlWjRCwpLljgQSG3pWdNAJDDU0rzOuyEJ bgUQ== MIME-Version: 1.0 X-Received: by 10.43.163.129 with SMTP id mo1mr10312028icc.61.1428352708213; Mon, 06 Apr 2015 13:38:28 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.17.194 with HTTP; Mon, 6 Apr 2015 13:38:28 -0700 (PDT) In-Reply-To: <1858440.dQ4AvDcZf7@ralph.baldwin.cx> References: <1858440.dQ4AvDcZf7@ralph.baldwin.cx> Date: Mon, 6 Apr 2015 13:38:28 -0700 X-Google-Sender-Auth: G3IQqydW80K-_si1QdHIZTV4cxM Message-ID: Subject: Re: x86: finding interrupts that aren't being accounted for? From: Adrian Chadd To: John Baldwin Content-Type: text/plain; charset=UTF-8 Cc: "freebsd-arch@freebsd.org" X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Apr 2015 20:38:29 -0000 On 6 April 2015 at 12:18, John Baldwin wrote: > On Monday, April 06, 2015 12:21:29 AM Adrian Chadd wrote: >> Hi, >> >> I have an .. odd problem on a Lenovo X230. >> >> I just threw in a very old wifi card (Intel 3945) into the expresscard >> (pcie) slot. Now, we don't have any pcie-hp support in -HEAD just yet, >> but i wasn't expecting the system to crawl to a halt. >> >> When I unplug it, everything returns to normal. >> >> Other cards don't do this. >> >> So, I figured it may be interrupt spam - but vmstat -ia shows no >> interrupts going crazy. >> >> pmcstat -S CPU_CLK_UNHALTED_CORE -T -w 5 doesn't register anything >> either - only a handful of background samples. >> >> However, /counter/ mode pmc tells a different story - pmcstat -s >> CPU_CLK_UNHALTED_CORE -w 1 shows all four cores going at 110% when the >> card is inserted, with brief periods of idle. Once I remove the card, >> the counters go back down to zero. >> >> My working theory is: something is chewing CPU and it's likely >> interrupts, but if it is, it's something far, far earlier than the x86 >> interrupt C code, which counts interrupts and spurious events. >> >> So - has anyone diagnosed this stuff on FreeBSD/x86 before? I was kind >> of hoping we'd at least get accurate statistics about spurious >> interrupts, and if we don't, I'd like to understand why. >> >> Thanks! > > SMM? Perhaps SMM doesn't hide itself from PMC counters (but it can hide itself > from samples). > > If it is SMM there's not really anything you can do about it. Try getting a > KTR_SCHED trace and looking at it in schedgraph. When I've seen SMM isuses in > the past it shows up as hole in the graph where nothing happens in the system. > > In your case you could perhaps be getting PCI errors that are triggering the > SMM handler. Perhaps compare pciconf -le before and after to see if there are > any changes. Hm, ok. Can we extract PCIe errors yet? -adrian