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SubjectRe: [PATCH v3 00/20] Speculative page faults
On Thu, 28 Sep 2017 14:29:02 +0200 Laurent Dufour <ldufour@linux.vnet.ibm.com> wrote:

> > Laurent's [0/n] provides some nice-looking performance benefits for
> > workloads which are chosen to show performance benefits(!) but, alas,
> > no quantitative testing results for workloads which we may suspect will
> > be harmed by the changes(?). Even things as simple as impact upon
> > single-threaded pagefault-intensive workloads and its effect upon
> > CONFIG_SMP=n .text size?
>
> I forgot to mention in my previous email the impact on the .text section.
>
> Here are the metrics I got :
>
> .text size UP SMP Delta
> 4.13-mmotm 8444201 8964137 6.16%
> '' +spf 8452041 8971929 6.15%
> Delta 0.09% 0.09%
>
> No major impact as you could see.

8k text increase seems rather a lot actually. That's a lot more
userspace cacheclines that get evicted during a fault...

Is the feature actually beneficial on uniprocessor?

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