Sorry yeah should have specified that - I forgot that FromDevice is different on Linux.
I am on FreeBSD 7.2-STABLE. Also, I am using Click v1.7.0rc1, but I compared FromDevice.u and the relevant portions of routerthread.cc to HEAD and didn't see anything different. - Ian Eddie Kohler wrote: > 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
