Re: [PATCH RT] Fix RT balancing tasks pulling

[Josh Triplett]

On Tue, 2007-07-24 at 15:42 +0200, SÃbastien Duguà wrote:
>   this one-liner fixes a bug in balance_rt_tasks() which sometimes manifests by
> having a lower prio task being scheduled while a higher prio task is sitting
> waiting on another runqueue.
> 
>   This is pretty hard to reproduce on low cpu count machines, for example, I
> had to have sched_football run in a loop for ~38h before it failed on a dual HT
> Xeon box.

Very impressive find, and this does seem to improve things in some
cases.

However, with 2.6.22.1-rt8, which includes this patch, I still managed
to get some failures after a few hours on an 8-way (quad dual-core) box.
Preliminary results so far:
    420 Final ball position: 0
      2 Final ball position: 1

- Josh Triplett


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