Re: [TEST RESULT]massive_intr.c -- cfs/vanilla/sd-0.40

From: Ingo Molnar
Date: Sat Apr 14 2007 - 08:03:28 EST



* surya.prabhakar@xxxxxxxxx <surya.prabhakar@xxxxxxxxx> wrote:

> Hi Ingo,
> Did a test with massive_intr.c on a standard linux desktop.
> for vanilla, con's Sd-0.40 and cfs.

thanks!

> [surya@bluegenie tests]$ ./massive_intr 10 10
> 002435 00000120
> 002439 00000120
> 002441 00000120
> 002434 00000120
> 002436 00000120
> 002440 00000120
> 002432 00000120
> 002437 00000120
> 002433 00000120
> 002438 00000120
>
> Felt it is too much fair, will try another pass ;)

hehe :)

> [surya@bluegenie tests]$ ./massive_intr 10 10
> 002961 00000121
> 002965 00000120
> 002964 00000121
> 002959 00000120
> 002956 00000121
> 002963 00000121
> 002960 00000121
> 002962 00000121
> 002958 00000122
> 002957 00000122

btw., other schedulers might work better with some more test-time: i'd
suggest to use 60 seconds (./massive_intr 10 60) [or maybe more, using
more threads] to see long-term fairness effects.

> [...] Will be trying out ringtest in the next round.

cool. ringtest.c is intended to be used the following way: start it, it
will generate a 99% busy system (but it is using a ring of 100 tasks,
where each tasks runs for 100 msecs then sleeps for 1 msec, so every
task gets a turn every 10 seconds). If you add a pure CPU hog to the
system, for example an infinite shell loop:

while :; do :; done &

then a 'fair' scheduler would give roughly 50% of CPU time to the CPU
hog (and the ringtest.c tasks take up the other 50%).

Ingo
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