From owner-freebsd-net@FreeBSD.ORG Sat Sep 12 09:07:56 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D25BF1065670 for ; Sat, 12 Sep 2009 09:07:56 +0000 (UTC) (envelope-from rihad@mail.ru) Received: from mx73.mail.ru (mx73.mail.ru [94.100.176.87]) by mx1.freebsd.org (Postfix) with ESMTP id 8F57B8FC15 for ; Sat, 12 Sep 2009 09:07:56 +0000 (UTC) Received: from mx48.mail.ru (mx48.mail.ru [94.100.176.62]) by mx73.mail.ru (mPOP.Fallback_MX) with ESMTP id D79F6650207 for ; Sat, 12 Sep 2009 11:27:20 +0400 (MSD) Received: from [217.25.27.27] (port=63228 helo=[217.25.27.27]) by mx48.mail.ru with asmtp id 1MmN0w-0002H2-00 for freebsd-net@freebsd.org; Sat, 12 Sep 2009 11:27:18 +0400 Message-ID: <4AAB4D56.30207@mail.ru> Date: Sat, 12 Sep 2009 12:27:18 +0500 From: rihad User-Agent: Mozilla-Thunderbird 2.0.0.22 (X11/20090706) MIME-Version: 1.0 To: freebsd-net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam: Not detected X-Mras: Ok Subject: [POLLING] strange interrupt/system load X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: "rihad@mail.ru >> rihad" List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Sep 2009 09:07:56 -0000 The box experiences ~230 mbit/s traffic flow through it. I've doubled some sysctls after reading polling(4): kern.polling.each_burst=10 # was: 5 kern.polling.burst_max=350 # was: 150 FreeBSD 7.2-RELEASE-p3 amd64 HZ=1000 Now for the fun part. With kern.polling.idle_poll = 1 top shows: CPU: 0.0% user, 0.0% nice, 26.9% system, 3.1% interrupt, 70.0% idle ~8000 interrupts/s total according to systat -vmstat: 1999 cpu0: time 2000 cpu1: time 1999 cpu2: time 1999 cpu3: time With kern.polling.idle_poll = 0 top shows: CPU: 0.0% user, 0.0% nice, 0.0% system, 13.9% interrupt, 86.0% idle Still the same ~8000 clock interrupts/s. Under both scenarios polling is enabled on both em0 and em1 through ifconfig. 1) Why is the interrupt load relatively high with polling enabled? 2) How come 13.9% interrupts are not also in the first scenario if their total rate is the same (~8000)? Thanks.