Re: scheduler vs hardware? (was Re: another i7 (linux) bug?)

From: Mike Galbraith
Date: Fri Jan 22 2010 - 02:19:33 EST


> if I run a cpu intensive process with the lowest priority (19
> from man nice) I obtain much better performance that with the
> highest priority available (-20 from man nice).
>
> For example the same file is processed by lame in 8.7 seconds
> at the lowest priority, and in 12 seconds at the highest
> priority. Before posting a bug I wold like to understand if
> this is a problem related to the i7 mobile (my processor is a
> i7 Q720).
>
> As far as I tested on the same laptop series (dell studio 15),
> with the same kernel this problem does not exists.

So you only see this on the i7. That's odd. Can you try 33-rc5?

Posting a reliable reproducer would be nice. It'd also be nice to see
what all is running when you see this, and where.

-Mike

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