Re: [PATCH 7/7] s390/vdso: Wire up getrandom() vdso implementation

Heiko Carstens
2024-09-13T17:37:54Z

On Fri, Sep 13, 2024 at 04:57:22PM +0200, Jason A. Donenfeld wrote:
> On Fri, Sep 13, 2024 at 04:16:51PM +0200, Heiko Carstens wrote:
> > On Fri, Sep 13, 2024 at 03:53:43PM +0200, Jason A. Donenfeld wrote:
> > > On Fri, Sep 13, 2024 at 03:05:43PM +0200, Heiko Carstens wrote:
> > > > The vdso testcases vdso_test_getrandom and vdso_test_chacha pass.
> > >
> > > I'd be curious to see the results of ./vdso_test_getrandom bench-single
> > > and such.
> >
> > It looks like this with two layers of hypervisors in between, but that
> > shouldn't matter too much for this type of workload:
> >
> > $ ./vdso_test_getrandom bench-single
> > vdso: 25000000 times in 0.493703559 seconds
> > libc: 25000000 times in 6.371764073 seconds
> > syscall: 25000000 times in 6.584025337 seconds
>
> Cool. I'll amend that to the commit message, perhaps, so we have some
> historical snapshot of what it does. What cpu generation/model is this?

That was on a z16 machine.