Re: Slowdown on high-load machines with 3000 sockets

Christian Schmid
2005-03-05T16:46:48Z

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Attached is another traffic-image. This one is with 2.6.10 and a 3/1 split, preemtive kernel, so all
defaults.

The first part is where I throttled the whole thing to 100 MBit in order to build up a traffic-jam ;)

When I released it, it jumped up immediately but suddenly it goes down (each pixel is one second)
Playing around with min_free_kbytes didnt help. Where it goes up again I set lower_zone_protection
to 1024000 and where it goes down I set it to 0 again and where it goes up the last time... guess..

Well I was only able to test this with 3500 sockets. I will try to jam up tomorrow to reach 5000
sockets to see if that is really the reason.

Nick Piggin wrote:
> Christian Schmid wrote:
>
>> This issue has been tracked down more. This bug does NOT appear if I
>> disable preemtive kernel.
>> Maybe this helps.
>>
>
> Yes, it may help - can you boot with profile=schedule and get
> the results for say, a 30 second period while the application
> is experiencing problems?
>
> So:
>
> start application
> wait till it hits slowdown
> readprofile -r ; sleep 30 ; readprofile > schedprof.out
>
> and send schedprof.out, please?
>
> Thanks,
> Nick
>
>
>

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