On Mon, Feb 21, 2005 at 12:12:51AM +0100, Daniel Egger <de@xxxxxxxxxx> wrote:
> >Linux will not keep two threads running on a single cpu if both are
> >ready
> >and nothing else is running, regardless of locality etc., as the kernel
> >lacks the tools to effectively decide wether threads should stay on a
> >cpu
> >or not.
>
> Yes and no. I just figured out that the tools I were
> looking for are called schedutils and can be used to
> change the affinity settings of a process, i.e. pin
> it to some CPU or allow it to migrate as the kernel
> decides between a set of CPUs.
I should have said "unless specially instructed to do so", i.e., not by
default.
> Forcing the NPTL implementation to degrade to legacy
BTW, is this 2.4 or 2.6?
> I can force it to use both CPUs now, but even with
> 200% utilization it is 2s slower to run this stupid
> ubenchmark than on 1 CPU without threads.
Now, that's definitely a result then :)
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