Re: [RFC PATCH] qspinlock: Improve performance by reducing load instruction rollback

From: Ingo Molnar
Date: Tue Oct 20 2015 - 04:49:16 EST



* Ling Ma <ling.ma.program@xxxxxxxxx> wrote:

> > So it would be nice to create a new user-space spinlock testing facility, via
> > a new 'perf bench spinlock' feature or so. That way others can test and
> > validate your results on different hardware as well.
>
> Attached the spinlock test module . Queued spinlock will run very slowly in user
> space because process switch context, it is OK for spinlock-test implementation
> with kernel module ?

Not sure what you mean by 'because process switch context': if you pin the test
tasks to individual CPUs and make sure there's nothing else running it should be
equivalent to kernel-space execution.

Thanks,

Ingo
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