On 08/08/2013 10:06 PM, Rafał Miłecki wrote: > Hey, > > I was doing some tests of ethernet performance on Broadcom's SoCs and > I may need your advise on that. > > As you know transfers between separated VLANs aren't really nice for > the CPU. Linux has to receive packets, pass them through the firewall > and them send to the target VLAN. I'm aware we can't expect full speed > in that case, but I'm a little worried by the performance anyway. > > I did some tests using "iperf" for various transfers. > 1) Between two machines in the same VLAN: 710Mb/s > 2) Between separated VLANs (WAN to LAN): 90Mb/s > 3) Machine to router (iperf -s on OpenWrt): 180Mb/s
I have seen similar results with different devices, but I think the CPU of the BCM4706 should be pretty fast compared to the older SoCs. > That 90Mb/s speed it pretty slow, there are Internet providers with a > faster connections in their offer. So I really would like to improve > that. I know Broadcom managed to get much faster transfers with their > firmware, so it's definitely do-able. Broadcom hacked the network stack to offload some parts to some special hardware. > Do you have any suggestions on achieving that? I was doing above test > with some BCM4706 router, in "top" I noticed "sirq" eating 99% of the > CPU (similar report: https://dev.openwrt.org/ticket/7356). > > Should I play with some profiler? > /proc/profile (and readprofile user space tool) doesn't support > profiling modules :( You can compile bgmac into the kernel, the results you get should be the same as you would get for the module. You just have to change target/linux/brcm47xx/config-3.10 . > I didn't play much time with oprofile yet, unfortunately it's new > profiling method doesn't support MIPS > (http://oprofile.sourceforge.net/doc/perf_events.html) - so I have to > play with legacy profiling method. Felix did some profiling on ath9k and mac80211, but I do not know If he did that on mips or x86. @Felix could you please tell us something about profiling in OpenWrt on Mips? > Anyway, maybe you have some suggestions that will help me focus my > efforts on the right direction? Hauke _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
