From owner-freebsd-arch@FreeBSD.ORG Mon Apr 6 07:21:30 2015 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 51FC2D69 for ; Mon, 6 Apr 2015 07:21:30 +0000 (UTC) Received: from mail-ie0-x231.google.com (mail-ie0-x231.google.com [IPv6:2607:f8b0:4001:c03::231]) (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 1AF81F12 for ; Mon, 6 Apr 2015 07:21:30 +0000 (UTC) Received: by iedfl3 with SMTP id fl3so18053894ied.1 for ; Mon, 06 Apr 2015 00:21:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:date:message-id:subject:from:to:content-type; bh=Ygj1Iwr3IGd094X+E0yNJm3zpCcLcfcXCVBXRagVHj0=; b=Or/06cSWt79TIj/p4eP7bvmxa0nzRshxOzhuXjRLnV1hoj3qbB10kXlWi7QTkHQ53+ k68WvlI+n983NHMg/0c7/Pvd3LcD4HqyME9ux0ikucKlQkWjU2TgHwEeW2MowCEiuYah ffS1i6J8us9fN8KIPK90hBQEpLRrBeF7cMbBhgniw+8LyBm1Jdk46S75iRmKaF0k+1MY UHwR5vYju+qxfHFXDiZytFDZkR0CUrJ6YzYYnGwFFdmebRJCi3OV2SherDkorToVJyvf ElT4FFzkoagjFVWSaDx+6QeIgDMFC1E3xQ2EA5NM9FQt1UuRaTkw4ILxSjU1e7/o7JFe l1Yw== MIME-Version: 1.0 X-Received: by 10.50.107.7 with SMTP id gy7mr21131544igb.49.1428304889582; Mon, 06 Apr 2015 00:21:29 -0700 (PDT) Sender: adrian.chadd@gmail.com Received: by 10.36.17.194 with HTTP; Mon, 6 Apr 2015 00:21:29 -0700 (PDT) Date: Mon, 6 Apr 2015 00:21:29 -0700 X-Google-Sender-Auth: cAupZCPDefq6O_xhicWASYZkSVI Message-ID: Subject: x86: finding interrupts that aren't being accounted for? From: Adrian Chadd To: "freebsd-arch@freebsd.org" Content-Type: text/plain; charset=UTF-8 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 07:21:30 -0000 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! -adrian