From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bay0-omc1-s39.bay0.hotmail.com (bay0-omc1-s39.bay0.hotmail.com [65.54.246.111]) by ozlabs.org (Postfix) with ESMTP id A2C31DDE2C for ; Sat, 10 Feb 2007 01:16:46 +1100 (EST) Message-ID: In-Reply-To: <689CB232690D8D4E97DA6C76DA098E6C0360F790@XCO-EXCHVS1.xlnx.xilinx.com> From: "Ming Liu" To: rick.moleres@xilinx.com Subject: RE: Speed of plb_temac 3.00 on ML403 Date: Fri, 09 Feb 2007 14:16:43 +0000 Mime-Version: 1.0 Content-Type: text/plain; charset=gb2312; format=flowed Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Dear Rick, Again the problem of TEMAC speed. Hopefully you can give me some suggestion on that. >With a 300Mhz system we saw about 730Mbps Tx with TCP on 2.4.20 >(MontaVista Linux) and about 550Mbps Tx with TCP on 2.6.10 (MontaVista >again) - using netperf w/ TCP_SENDFILE option. We didn't investigate the >difference between 2.4 and 2.6. Now with my system(plb_temac and hard_temac v3.00 with all features enabled to improve the performance, Linux 2.6.10, 300Mhz ppc, netperf), I can achieve AT MOST 213.8Mbps for TCP TX and 277.4Mbps for TCP RX, when jumbo-frame is enabled as 8500. For UDP it is 350Mbps for TX, also 8500 jumbo-frame is enabled. So it looks that my results are still much less than yours from Xilinx(550Mbps TCP TX). So I am trying to find the bottleneck and improve the performance. When I use netperf to transfer data, I noticed that the CPU utilization is almost 100%. So I suspect that CPU is the bottleneck. However other friends said the PLB structure is the bottleneck, because when the CPU is lowered to 100Mhz, the performance will not change much, but if the PLB frquency is lowered, it will. Then they conclude that with the PLB structure, the CPU will wait a long time to load and store data from DDR. So PLB is the criminal. Then come some questions. 1. Is your result from the GSRD structure or just the normal PLB_TEMAC? Will the GSRD achieve a better performance than the normal PLB_TEMAC? 2. Which on earch is the bottleneck for the network performance, CPU or PLB structure? Is that possible for PLB to achieve a much higher throughput? 3. Because your result is based on Montavista Linux. Is there any difference between MontaVista Linux and the general open-source linux kernel which could lead to different performance? I know that many persons including me are struggling to improve the performance of PLB_TEMAC on ML403. So please give us some hints and suggestions with your experience and research. Thanks so much for your work. BR Ming _________________________________________________________________ 与联机的朋友进行交流，请使用 MSN Messenger: http://messenger.msn.com/cn