Ian, What OS is this running on? Are you using pcap?
Eddie On 3/19/10 10:45 AM, Ian Rose wrote: > Hi Eddie, > > I'd be more than glad to send along my "real" config, but its really big > and uses quite a lot of custom elements that won't mean anything to you > without the source code. > > However, just for testing these changes I used: > > FromDevice(ath1, ENCAP 802_11_RADIO, PROMISC true, HEADROOM 196) -> > Discard; > > I am seeing about a 2x CPU usage difference when I use _iters_per_os = 2 > vs 64. > > - Ian > > > Eddie Kohler wrote: >> Hi Ian, >> >> (1) I would completely appreciate seeing your config, just to see if >> there's anything that might cause the extra CPU usage. BUT: >> >> (2) _iters_per_os is set that way just, I think, as a random guess. >> ANd that guess is at least 5 years old and probably more. I think it >> would be OK to set it to 2 for everyone. >> >> Eddie >> >> >> On 3/18/10 8:06 PM, Ian Rose wrote: >>> Hi all - >>> >>> In lib/routerthread.cc there is the following code: >>> >>> #if CLICK_USERLEVEL >>> _iters_per_os = 64; /* iterations per select() */ >>> #else >>> _iters_per_os = 2; /* iterations per OS schedule() */ >>> #endif >>> >>> I'm curious if there is a particular rationale behind the value 64 for >>> userlevel click. Is it simply the case that this value works pretty >>> well for most of the typical click configurations that were tested? In >>> my (admittedly brief) testing, it appears that this parameter choice >>> imposes a CPU overhead of ~3x for [some?] select-heavy applications, by >>> which I mean configs that spend most of their time calling selected() on >>> elements, rather executing tasks or timers. For example, my particular >>> app uses around 15-20% CPU with the above values, but if I change the 64 >>> to a 2, the CPU usage drops to 5-6%. >>> >>> Obviously this might simply be a case of the default parameters not >>> being particularly good for my specific situation, but I thought I'd >>> check since the performance difference seemed pretty significant. >>> >>> cheers, >>> - Ian >>> _______________________________________________ >>> click mailing list >>> [email protected] >>> https://amsterdam.lcs.mit.edu/mailman/listinfo/click _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
