From owner-freebsd-current@FreeBSD.ORG Tue Jul 20 17:15:59 2010 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 06F37106567F for ; Tue, 20 Jul 2010 17:15:59 +0000 (UTC) (envelope-from dan@dan.emsphone.com) Received: from email1.allantgroup.com (email1.emsphone.com [199.67.51.115]) by mx1.freebsd.org (Postfix) with ESMTP id A05C38FC14 for ; Tue, 20 Jul 2010 17:15:58 +0000 (UTC) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by email1.allantgroup.com (8.14.0/8.14.0) with ESMTP id o6KHFuwS075974 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 20 Jul 2010 12:15:57 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (smmsp@localhost [127.0.0.1]) by dan.emsphone.com (8.14.4/8.14.4) with ESMTP id o6KHFuPs099108 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 20 Jul 2010 12:15:56 -0500 (CDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.14.4/8.14.3/Submit) id o6KGk0pV028213; Tue, 20 Jul 2010 11:46:00 -0500 (CDT) (envelope-from dan) Date: Tue, 20 Jul 2010 11:46:00 -0500 From: Dan Nelson To: Doug Barton Message-ID: <20100720164600.GA85770@dan.emsphone.com> References: <20100717192128.GM2381@deviant.kiev.zoral.com.ua> <20100718103003.GO2381@deviant.kiev.zoral.com.ua> <4C43541C.3060101@FreeBSD.org> <20100718194109.GU2381@deviant.kiev.zoral.com.ua> <4C435CBE.50500@FreeBSD.org> <20100718202338.GI5485@dan.emsphone.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-OS: FreeBSD 8.1-PRERELEASE User-Agent: Mutt/1.5.20 (2009-06-14) X-Virus-Scanned: clamav-milter 0.96 at email1.allantgroup.com X-Virus-Status: Clean X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.0.2 (email1.allantgroup.com [199.67.51.78]); Tue, 20 Jul 2010 12:15:57 -0500 (CDT) X-Scanned-By: MIMEDefang 2.45 Cc: Kostik Belousov , freebsd-current@freebsd.org, Rui Paulo Subject: Re: Why is intr taking up so much cpu? 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: Tue, 20 Jul 2010 17:15:59 -0000 In the last episode (Jul 19), Doug Barton said: > On Sun, 18 Jul 2010, Dan Nelson wrote: > > You can also use dtrace to get a count of callouts and their time spent. > > Run this for a few seconds then hit ^C: > > Okey dokey, here you go: > > http://people.freebsd.org/~dougb/normal-dtrace.txt > http://people.freebsd.org/~dougb/bad-dtrace.txt I don't see any real difference between those two runs, so maybe it's not a callout eating your CPU. How about running this for a few seconds, which will print all the stack traces seen during the sampling period: dtrace -n 'profile:::profile-276hz { @pc[stack()]=count(); }' On an otherwise idle system, you should see most of the counts in cpu_idle, with the remainder clustered in whatever code is eating your CPU. -- Dan Nelson dnelson@allantgroup.com