From: Pablo Bitton <pablo.bit...@gmail.com> Date: Mon, Mar 2, 2009 at 11:52 AM Subject: Re: DM6446 Ethernet MAC performance To: "Subrahmanya, Chaithrika" <chaithr...@ti.com>
Hi, I've found that the issue below can be demonstrated by compiling the following two revisions: http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git;a=commit;h=73af72ed66644dc3703b0bfd74285f30f1fe408f - before PHY refactoring http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git;a=commit;h=b2cbe2f96aa420efcd312a1de8f7fd8e511b2a55 - after PHY refactoring Build commands used: $ make distclean $ make davinci_dm644x_evm_defconfig $ make uImage The kernels above were loaded to the same EVM, using the same network setup - and had the following performace: 73af72ed66644dc3703b0bfd74285f30f1fe408f - 72Mbit/s (upload) b2cbe2f96aa420efcd312a1de8f7fd8e511b2a55 - 21Mbit/s (upload) This experiment was repeated several times, so probably network congestion is not the reason for performance degradation seen. Regards, Pablo. On Wed, Feb 25, 2009 at 7:44 PM, Pablo Bitton <pablo.bit...@gmail.com> wrote: > My host is Ubuntu 8.04, running over VMware, connected to DVEVM by 2 switches. > > I agree that this setup may cause network congestion. > However, I've ran iperf over DVEVM and the host several times - and > the results were pretty much the same. > > The only thing that made the throughput to change dramatically was > switching back and forth between 2.6.29-rc4 and 2.6.28-rc6. > > How should I debug this issue? > Are there any recommended profiling tools for kernel's network performance? > > Thanks in advance. > > On Tue, Feb 24, 2009 at 1:39 PM, Subrahmanya, Chaithrika > <chaithr...@ti.com> wrote: >>> Hi to all, >>> >>> I've tested Linux kernel 2.6.29-rc4-davinci1 >>> (http://git.kernel.org/?p=linux/kernel/git/khilman/linux- >>> davinci.git;a=commit;h=582ad6bcceb7c8f0c828e71e810fd40fed7af6c3) >>> for Ethernet performance. >>> Kernel was compiled was done by CodeSourcery 2008q3 (gcc 4.3.2) using >>> davinci_evm_dm644x_defconfig. >>> >>> After booting, iperf v2.0.4 was run on the target (DVEVM board) and on >>> the host PC (Ubuntu 8.04) for ten seconds (using default settings): >>> target -> target (over localhost): 190Mbit/s >>> host (connecting to) -> target: 31Mbit/s >>> target (connecting to) -> host: 71Mbit/s >>> >>> Do the values above make sense? Can anyone confirm them? >> >> The PHY layer should not cause any decrease in the performance as it >> is used only to access the PHY using the MII. Please provide some more >> details like the connection setup used- whether it was on a network >> or back to back. The network dynamics will alter the performance. >> >> Regards, >> Chaithrika >> >>> >>> Thanks in advance. >>> >>> P.S. >>> When running the same test on 2.6.28-rc6 (from >>> http://git.kernel.org/?p=linux/kernel/git/khilman/linux-davinci.git), >>> before PHY was refactored out from davinci_emac, the results were >>> better: >>> host (connecting to) -> target: 73Mbit/s >>> target (connecting to) -> host: 57Mbit/s >>> >>> _______________________________________________ >>> Davinci-linux-open-source mailing list >>> Davinci-linux-open-source@linux.davincidsp.com >>> http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source > _______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
