From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965013AbXDAUHl (ORCPT ); Sun, 1 Apr 2007 16:07:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964917AbXDAUHl (ORCPT ); Sun, 1 Apr 2007 16:07:41 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:36570 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964873AbXDAUHj (ORCPT ); Sun, 1 Apr 2007 16:07:39 -0400 Message-ID: <461010F9.7040706@us.ibm.com> Date: Sun, 01 Apr 2007 13:07:21 -0700 From: Nivedita Singhvi User-Agent: Thunderbird 1.5.0.10 (X11/20070221) MIME-Version: 1.0 To: Dave Sperry CC: linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org, netdev Subject: Re: Poor UDP performance using 2.6.21-rc5-rt5 References: <461004CE.1030009@ieee.org> In-Reply-To: <461004CE.1030009@ieee.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Sperry wrote: > Hi (adding netdev to cc list) > I have a dual core Opteron machine that exhibits poor UDP performance > (RT consumes more than 2X cpu) with the 2.6.21-rc5-rt5 as compared to > 2.6.21-rc5. Top shows the IRQ handler consuming a lot of CPU. Dave, any chance you've got oprofile working on the -rt5? And I'm assuming nothing very different in the stats or errors through both runs? thanks, Nivedita > The mother board is a Supermicro H8DME-2 with one dual core Opteron > installed. The networking is provided by the on board nVidia MCP55Pro chip. > > The RT test is done using netperf 2.4.3 with the server on an IBM LS20 > blade running RHEL4U2 and the Supermicro running netperf under RHEL5 > with 2.6.21-rc5-rt5. > The Non-RT test was done on the exact same setup except 2.6.21-rc5-rt5 > was loaded on the SuperMicro board. > > Cyclesoak was used to measure CPU utilization in all cases. > > > > Here are the RT results > ########################################################3 > ## 2.6.21-rc5-rt5 > ####################################################### > $ !netper > netperf -l 100 -H 192.168.70.11 -t UDP_STREAM -- -m 1025 > UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to > 192.168.70.11 (192.168.70.11) port 0 AF_INET > Socket Message Elapsed Messages > Size Size Time Okay Errors Throughput > bytes bytes secs # # 10^6bits/sec > > 126976 1025 100.00 8676376 0 711.46 > 135168 100.00 8676376 711.46 > > ########## cyclesoak during test > $ ./cyclesoak > using 2 CPUs > System load: -0.1% > System load: 40.5% > System load: 51.6% > System load: 51.5% > System load: 50.9% > System load: 50.7% > System load: 50.8% > System load: 50.7% > System load: 50.6% > > ######## top during test > top - 13:26:48 up 8 min, 4 users, load average: 1.74, 0.46, 0.15 > Tasks: 149 total, 4 running, 145 sleeping, 0 stopped, 0 zombie > Cpu(s): 0.7%us, 16.8%sy, 50.6%ni, 0.0%id, 0.0%wa, 25.6%hi, 6.3%si, > 0.0%st > Mem: 2035444k total, 465888k used, 1569556k free, 28840k buffers > Swap: 3068372k total, 0k used, 3068372k free, 318668k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 3865 eadi 39 19 6804 1164 108 R 100 0.1 0:38.25 cyclesoak > 2715 root -51 -5 0 0 0 S 51 0.0 0:09.52 IRQ-8406 > 3867 eadi 25 0 6440 632 480 R 34 0.0 0:06.03 > netperf 19 root -51 0 0 0 0 S 13 0.0 > 0:02.33 softirq-net-tx/ > 3866 eadi 39 19 6804 1164 108 R 1 0.1 0:20.47 cyclesoak > 3167 root 25 0 29888 1180 888 S 0 0.1 0:00.93 automount > 3861 eadi 15 0 12712 1076 788 R 0 0.1 0:00.19 top > 1 root 18 0 10308 668 552 S 0 0.0 0:00.67 init > 2 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/0 > 3 root RT 0 0 0 0 S 0 0.0 0:00.00 posix_cpu_timer > 4 root -51 0 0 0 0 S 0 0.0 0:00.00 softirq-high/0 > 5 root -51 0 0 0 0 S 0 0.0 0:00.00 softirq-timer/0 > 6 root -51 0 0 0 0 S 0 0.0 0:00.00 softirq-net-tx/ > 7 root -51 0 0 0 0 S 0 0.0 0:00.00 softirq-net-rx/ > 8 root -51 0 0 0 0 S 0 0.0 0:00.00 softirq-block/0 > > ######################## > The baseline results: > RHEL5 with 2.6.21-rc5 kernel > ############################## > > $ netperf -l 100 -H 192.168.70.11 -t UDP_STREAM -- -m 1025 > > UDP UNIDIRECTIONAL SEND TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to > 192.168.70.11 (192.168.70.11) port 0 AF_INET > Socket Message Elapsed Messages > Size Size Time Okay Errors Throughput > bytes bytes secs # # 10^6bits/sec > > 126976 1025 100.00 11405485 0 935.24 > 135168 100.00 11405485 935.24 > > ####################################### > $ ./cyclesoak > using 2 CPUs > System load: 7.6% > System load: 29.6% > System load: 29.6% > System load: 28.9% > System load: 24.9% > System load: 25.0% > System load: 24.8% > System load: 24.9% > > ####################################### > top:top - 13:52:22 up 10 min, 6 users, load average: 1.46, 0.43, 0.17 > Tasks: 118 total, 4 running, 114 sleeping, 0 stopped, 0 zombie > Cpu(s): 0.5%us, 9.8%sy, 75.7%ni, 0.0%id, 0.0%wa, 5.8%hi, 8.1%si, > 0.0%st > Mem: 2057200k total, 459128k used, 1598072k free, 29020k buffers > Swap: 3068372k total, 0k used, 3068372k free, 318968k cached > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 3882 eadi 39 19 6804 1164 108 R 100 0.1 0:52.11 cyclesoak > 3881 eadi 39 19 6804 1164 108 R 65 0.1 0:38.47 cyclesoak > 3883 eadi 15 0 6436 632 480 R 35 0.0 0:18.26 netperf > 3879 eadi 15 0 12580 1052 788 R 0 0.1 0:00.15 top > 1 root 18 0 10308 664 552 S 0 0.0 0:00.48 init > 2 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/0 > 3 root 34 19 0 0 0 S 0 0.0 0:00.01 ksoftirqd/0 > 4 root RT 0 0 0 0 S 0 0.0 0:00.00 watchdog/0 > 5 root RT 0 0 0 0 S 0 0.0 0:00.00 migration/1 > 6 root 34 19 0 0 0 S 0 0.0 0:00.00 ksoftirqd/1 > > Any thoughts on how to fix this? > > Thanks, > -Dave > > > > > > > > > > > > - > To unsubscribe from this list: send the line "unsubscribe > linux-rt-users" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html