From mboxrd@z Thu Jan 1 00:00:00 1970 From: Karsten Desler Subject: Re: _High_ CPU usage while routing (mostly) small UDP packets Date: Tue, 7 Dec 2004 11:21:32 +0100 Message-ID: <20041207102132.GA28588@quickstop.soohrt.org> References: <20041206224107.GA8529@soohrt.org> <20041207002012.GB30674@quickstop.soohrt.org> <1102387595.1088.48.camel@jzny.localdomain> <20041207025456.GA525@soohrt.org> <1102389533.1089.51.camel@jzny.localdomain> <20041207032438.GA7767@soohrt.org> <1102390241.1093.59.camel@jzny.localdomain> <20041207040235.GA10501@soohrt.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jamal , Bernd Eckenfels , "David S. Miller" , netdev@oss.sgi.com, linux-kernel@vger.kernel.org Return-path: To: Karsten Desler Content-Disposition: inline In-Reply-To: <20041207040235.GA10501@soohrt.org> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org Karsten Desler wrote: > * jamal wrote: > > Beats me. Make sure it boots NAPI. Also if you can turn off ITR; intel > > loves to turn on that silly feature. > > ITR was in fact activated. I think i've disabled it now > (e1000.InterruptThrottleRate=0 in the kernel cmdline). > And as I'm reading the e1000 code, there is no way to enable/disable > NAPI without a recompile. So the fact that ethtool spat out -NAPI in > the version string means that NAPI is actually used. But looking and the int/s number, I'm not so sure anymore. Is there any other way to find out? # ethtool -i eth0|grep ^vers version: 5.5.4-k2-NAPI # ethtool -i eth1|grep ^vers version: 5.5.4-k2-NAPI CPU0 CPU1 169: 5 115554253 IO-APIC-level eth0 177: 78998347 5568 IO-APIC-level eth1 # sar -I 169 5 5 11:20:05 INTR intr/s 11:20:10 169 10401.40 11:20:15 169 10579.80 11:20:20 169 10965.20 11:20:25 169 10768.20 11:20:30 169 10460.60 Average: 169 10635.04 # sar -I 177 5 5 11:18:50 INTR intr/s 11:18:55 177 4769.74 11:19:00 177 4780.80 11:19:05 177 4669.74 11:19:10 177 4724.55 11:19:15 177 4748.50 Average: 177 4738.67 Cheers, Karsten