Re: Bug: 2.6.15 Process accounting fails to account for small timeslice loads (still)

From: Tim Schmielau
Date: Tue Jan 30 2007 - 12:48:54 EST


On Tue, 30 Jan 2007, Tom Burns wrote:

> The bug described back in 2004 in the following message still seems to exist:
>
> http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-05/4313.html
>
> Essentially, it appears that if a process sleeps before it uses up a
> complete jiffy then no charge is made to its process accounting table.

That's not a bug, it's a feature. ;-)

More seriously, it's a design decision. The benefit of exactly correct
micro bookkeeping does not seem to warrant the extra cost in terms of cpu
cycles spent in the accounting code.

IIRC there was a patch for that some years ago, if you are interested I
will try to find it. No idea how much work it would be to port it to
current kernels, though.

Tim
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