Re: Real-Time Preemption, comparison to 2.6.10-mm1

From: Lee Revell
Date: Tue Jan 04 2005 - 16:47:22 EST


On Tue, 2005-01-04 at 14:11 -0600, Mark_H_Johnson@xxxxxxxxxxxx wrote:
> The non RT application starvation for mm1 was much less
> pronounced but still present. I could watch the disk light
> on the last two tests & see it go out (and stay out) for an
> extended period. It does not make sense to me that a single RT
> application (on a two CPU machine) and a nice'd non RT application
> can cause this starvation behavior. This behavior was not
> present on the 2.4 kernels and seems to be a regression to me.

I think I am seeing this problem too. It doesn't just apply to RT
tasks, it seems that CPU bound tasks starve each other. I noticed that
with the RT kernel, a kernel compile or dpkg will starve evolution, to
the point where it takes 30 seconds to display a message. If I go and
background the CPU hog, the message renders _instantly_.

It's definitely present with 2.6.10-rc2 + RT (PK config) and absent with
2.6.10 vanilla. I need to figure out whether -mm has the problem.

Lee

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