On Thu, Sep 07, 2017 at 11:26:47PM +0200, Ingo Molnar wrote:
>
> * Eric Biggers <ebigge...@gmail.com> wrote:
>
> > On Thu, Sep 07, 2017 at 09:15:34AM +0200, Ingo Molnar wrote:
> > >
> > > * Eric Biggers <ebigge...@gmail.com> wrote:
> > >
> > > > Thanks for fixing these! I don't have time to review these in detail,
> > > > but I ran
> > > > the crypto self-tests on the affected algorithms, and they all pass. I
> > > > also
> > > > benchmarked them before and after; the only noticable performance
> > > > difference was
> > > > that sha256-avx2 and sha512-avx2 became a few percent slower. I don't
> > > > suppose
> > > > there is a way around that? Otherwise it's probably not a big deal.
> > >
> > > Which CPU model did you use for the test?
> > >
> > > Thanks,
> > >
> > > Ingo
> >
> > This was on Haswell, "Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz".
>
> Any chance to test this with the latest microarchitecture - any Skylake
> derivative
> Intel CPU you have access to?
>
> Thanks,
>
> Ingo
Tested with Skylake, "Intel(R) Core(TM) i5-6200U CPU @ 2.30GHz". The results
were the following which seemed a bit worse than Haswell:
sha256-avx2 became 3.5% slower
sha512-avx2 became 7.5% slower
Note: it's tricky to benchmark this, especially with just a few percent
difference, so don't read too much into the exact numbers.
Eric
