Dear Cliff and friends: Today, I test the click efficiency without driver, it's work very well. your point is right, thanks.
but both ethernet and wireless lead to cpu high loading. so I trace the element ToDevice code: ret = _dev->hard_start_xmit(skb1, _dev); this line send packet throuth driver. if don't excute this line. the cpu load is normal. if excute this line, only ToDevice(eth0) will have high cpu loading. I test ToDevice(ath0) too, the issue like ToDevice(eth0) too. I don't know click ToDevice use hard_start_xmit. why have the strange problem? the hard_start_xmit in the kernel is diffient with dev_queue_xmit. I guess in the ToDevice use interrupt have some conflict with kernel. how to solve the problem? Thanks 2009/11/30 Cliff Frey <[email protected]> > IRQ time is likely time spent in interrupt handlers... most likely your > drivers (ethernet and wireless) both install interrupt handlers. This is > _not_ time spent in click. This is time spent in your drivers. > > Softirq time is generally time spent in tasklets, either explicit tasklets > used by drivers or by rx_poll functions. Again, this is time spent in your > driver, not in click. > > If you want to choose what to optimize, then you must do what I suggested > in the first email, and measure the performance of each part of your system > individually. You could replace FromDevice with InfiniteSource and ToDevice > with (Counter -> Discard) and see what byte/packet rate click can achieve on > its own. > > You could run > > InfiniteSource -> Counter -> ToDevice > > And see how many packets/bytes per second your drivers are capable of > sending. > > Either way, I feel like your measurements indicate that it is not a click > performance problem, but in fact a driver performance problem. > > Good luck, > > Cliff > > > On Sun, Nov 29, 2009 at 5:01 AM, Yongheng Qi <[email protected]> wrote: > >> Dear Cliff >> >> My system use FromDevice get packet from wireless and ethernet driver. you >> mean FromDeivce used interrupt is irq but not the softirq? >> >> I can't distinguish between irq and softirq at driver , FromDevice and >> ToDevice. >> >> 2009/11/29 Cliff Frey <[email protected]> >> >>> 56% softirq implies to me that 56% of the time is spent in the packet >>> receive functions in your ethernet or wireless driver.... as click should >>> not be running at softirq context. 15% irq means that 15% of the time is >>> actually in interrupt handlers, again that is likely your wireless and/or >>> ethernet drivers. So I don't think that your performance problem is in >>> kclick itself. Probably you could get 10% better performance if you were >>> able to get rid of many many click elements in your data path... but I >>> really think that you should be looking at your ethernet/wireless drivers >>> instead. >>> >>> >>> As I said in my earlier email, you need to break down your problem into >>> smaller pieces before you can blame kclick for the performance. You could >>> also enable CONFIG_PROFILE in linux, which could give you insight into how >>> much time your drivers are spending on what lines of code... but it is a >>> fair amount of work. In addition, with some work you can get linux to also >>> profile your kernel modules... for instance: >>> http://lkml.indiana.edu/hypermail/linux/kernel/0405.1/1115.html >>> >>> Good luck. >>> >>> Cliff >>> >>> >>> On Sat, Nov 28, 2009 at 12:50 AM, Yongheng Qi <[email protected]> wrote: >>> >>>> I tested the NotifierQueue, the instance is the same as before. >>>> >>>> anyone have ideas? Thanks. >>>> >>>> This is the top result: >>>> >>>> Mem: 20540K used, 106700K free, 0K shrd, 0K buff, 6656K cached >>>> CPU: 0% usr 27% sys 0% nice 0% idle 0% io 15% irq 56% softirq >>>> Load average: 0.95 0.88 0.50 >>>> PID PPID USER STAT VSZ %MEM %CPU COMMAND >>>> 777 2 root RW 0 0% 99% [kclick] >>>> 807 691 root R 1960 2% 0% top >>>> 682 664 root S 1992 2% 0% /usr/sbin/dropbear -p 22 >>>> 691 682 root S 1972 2% 0% -ash >>>> >>>> >>> >> >> >> -- >> Yongheng Qi >> >> Mobile: +86 1390 119 7481 >> > > -- Yongheng Qi Mobile: +86 1390 119 7481 _______________________________________________ click mailing list [email protected] https://amsterdam.lcs.mit.edu/mailman/listinfo/click
