> 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. >
I am looking into this issue, will get back to you with my findings. I have not observed any large difference in performance numbers when I tested it earlier (for UDP). In fact there was some improvement for some cases. Thanks, Chaithrika > 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_______________________________________________ Davinci-linux-open-source mailing list Davinci-linux-open-source@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
