[Click] click optimize efficiency
Yongheng Qi
jetever at gmail.com
Mon Dec 7 07:29:30 EST 2009
this is the oprofile result, when I test, the top cpu is 100%:
samples % app name symbol name
297294 53.8607 vmlinux r4k_wait
22324 4.0444 vmlinux half_md4_transform
19912 3.6075 ath_hal.ko ar5416GetPendingInterrupts
18076 3.2748 ath_hal.ko ar5416SetInterrupts
8409 1.5235 ath_hal.ko ar5416GetTsf64
7193 1.3032 vmlinux do_ade
6897 1.2495 vmlinux handle_adel_int
6692 1.2124 ath_hal.ko ath_hal_reg_write
6608 1.1972 ath_dev.ko ath_rx_tasklet
6065 1.0988 merakiclick.ko IPFilter::push(int, Packet*)
5334 0.9664 merakiclick.ko SR2GatewaySelector::best_
gateway()
5219 0.9455 ath_hal.ko ar5416ProcTxDesc
4274 0.7743 ath_pci.ko ath_tx_startraw
3271 0.5926 vmlinux __local_bh_enable
2861 0.5183 ath_dev.ko ath_check_uapsdtriggers
2746 0.4975 ath_hal.ko ar5416Set11nRateScenario
2594 0.4700 ath_dev.ko ath_tx_complete_buf
2570 0.4656 vmlinux r4k_dma_cache_inv
2553 0.4625 merakiclick.ko SR2Forwarder::encap(Packet*,
Vector<IPAddress>, int)
2459 0.4455 merakiclick.ko WifiEncap::simple_action(Packet*)
2392 0.4334 merakiclick.ko packet_notifier_hook
2009/12/7 Yongheng Qi <jetever at gmail.com>
> Dear everyone：
>
> I don't success use oprofile on my system. but I try enable the linux
> profile: this is the high cpu loading profile info:
>
> root at OpenWrt:/etc# readprofile -m System.map | sort -nr | head -10
> 36396 *unknown*
> 22185 total 0.0121
> 5202 __copy_user 7.4314
> 1847 do_ade 2.3559
> 1716 r4k_wait 143.0000
> 1590 handle_adel_int 28.3929
> 799 r4k_dma_cache_wback_inv 4.5398
> 756 __do_softirq 3.6346
> 705 do_dsemulret 3.8315
> 640 ag71xx_poll 0.6324
>
> I think the "unknown" is click mode. accordint to before testing, click
> performece no problem. now use cpu more is r4k_wait and handle_adel_int .
>
> I don't know who use it.
>
> 2009/12/1 Yongheng Qi <jetever at gmail.com>
>
> By the way, I used kernel version is 2.6.26.5
>>
>> On 12/1/09, Yongheng Qi <jetever at gmail.com> wrote:
>> > 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 <cliff at meraki.com>
>> >
>> >> 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 <jetever at gmail.com>
>> 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 <cliff at meraki.com>
>> >>>
>> >>>> 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 <jetever at gmail.com>
>> >>>> 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
>> >
>>
>> --
>> Sent from my mobile device
>>
>> Yongheng Qi
>>
>> Mobile: +86 1390 119 7481
>>
>
>
>
> --
> Yongheng Qi
>
> Mobile: +86 1390 119 7481
>
--
Yongheng Qi
Mobile: +86 1390 119 7481
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