2013/8/14 Hauke Mehrtens <ha...@hauke-m.de>: > 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 >> >> 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. >> >> 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 :( >> 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. >> >> Anyway, maybe you have some suggestions that will help me focus my >> efforts on the right direction? >> > Hi Rafał, > > have you tried to use more compiler optimizations? Currently the brcm47x > target is optimized for MIPS r1 CPUs and not for the 74K (MIPS r2) CPU > which is used in the BCM4706.
MIPS32r1 vs MIPS32r2 should provide a very minimal performance boost, there is something else going on here. Such a CPU should be able to achieve at least Fast Ethernet speeds and does not even seem to do it. Stupid question, is the link between the switch and the CPU really linking at Gigabit speeds? -- Florian _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
