Re: [Lse-tech] [patch 2.6.0-test1] per cpu times

From: Mike Kravetz (kravetz@us.ibm.com)
Date: Fri Jul 18 2003 - 13:18:50 EST


On Fri, Jul 18, 2003 at 06:35:42PM +0200, Erich Focht wrote:
>
> This patch brings back the per CPU user & system times which one was
> used to see in /proc/PID/cpu with 2.4 kernels. Useful for SMP and NUMA
> scheduler development, needed for reasonable output in numabench /
> numa_test.
>

On a somewhat related note ...

We (Big Blue) have a performance reporting application that
would like to know how long a task sits on a runqueue before
it is actually given the CPU. In other words, it wants to
know how long the 'runnable task' was delayed due to contention
for the CPU(s). Of course, one could get an overall feel for
this based on total runqueue length. However, this app would
really like this info on a per-task basis.

Does anyone else think this type of info would be useful?

A patch to compute/export this info should be straight forward
to implement.

-- 
Mike
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