Re: Useful fork info? WAS Re: [BENCHMARK] fork_load module tested

[Ingo Molnar]

On Thu, 26 Sep 2002, Con Kolivas wrote:

> fork_load:
> Kernel                  Time            CPU             Ratio
> 2.4.19                  97.11           67%             1.33
> 2.4.19-ck7              72.34           92%             0.99
> 2.5.38                  75.32           92%             1.03
> 2.5.38-mm2              74.99           92%             1.03
> 
> 2.4.19: Children forked: 32750
> 2.4.19-ck7: Children forked: 6477
> 2.5.38: Children forked: 5545
> 2.5.38-mm2: Children forked: 5351
> 
> You can see clearly repeatedly forking a new process significantly slows
> down compile time for 2.4.19 but not the O(1) based kernels. However,
> the number of processes that are forked is significantly reduced.

shouldnt the CPU load be 100% for such a test? If it isnt then perhaps
some other thing factors in. VM load? And i dont understand how a faster
kernel forks less children in the end. Perhaps the test is hitting some
sort of resource limit which has a different default in 2.5?

	Ingo