On 2009-08-13, Wijnand Wiersma <wijn...@videre.net> wrote: > When investigating I see 80-90% of the CPU time is because of interupts. > Almost all interrupts are for the rl0 and rl1 interface. > > The interrupt load is not coupled to bandwith usage, we can use 60Mbit > without any problems. > I know rl(4) cards are crappy but I am wondering what could cause > these strange spikes? > It must be because of packets per second, but I can't find a offender.
almost certainly high PPS. you can watch the traffic with "systat ifs", maybe when you hit a high-load spike you could tcpdump and identify the actual traffic. (or setup pflow and nfdump/etc). > Are there any tweaks to mitigate the effects? > > Right after the load spikes (normally these last for 15 minutes) the > IPSEC tunnels are not in a usable state anymore. > Does anyone have a workaround for this? either of these options would probably help, but might not be (possible|practical): - use a faster cpu - change the nic; almost anything else would be better - convert the rl(4) driver to use MCLGETI - identify the cause of the packet flood and apply lart(8) http://www.xinu.nl/unix/humour/asr-manpages/lart.html
