Re: Instantaneous snapshot of CPU schedule

From: Alan Cox
Date: Tue Oct 27 2009 - 06:35:16 EST


On Tue, 27 Oct 2009 13:14:34 +0530 (IST)
J K Rai <jk.anurag@xxxxxxxxx> wrote:

> Hello
>
> Is there any utility using which we can take current (instantaneous) snapshot of process schedule on the linux based system from user land. Like use a system call or command to know what is running on each of the cpus 0..n-1 (assuming n cpus in the system). Output could be like tuple (pid, cpu_no).
>
> If such utility does not exist then kindly throw some light / ideas so that it could be implemented.

I'm not sure it would be terribly useful. You know what is running on at
least one of the processors - your snapshot tool. So for uniprocessor its
100% useless, for dual processor 50% useless.

It would also be incredibly expensive to serialize everything on the
system just to take a measurement.
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