Re: [RFC PATCH v4 00/11] powerpc: switch VDSO to C implementation.

From: Segher Boessenkool
Date: Mon Jan 20 2020 - 10:20:42 EST


On Mon, Jan 20, 2020 at 02:56:00PM +0000, Christophe Leroy wrote:
> >Nice! Much better.
> >
> >It should be tested on more representative hardware, too, but this looks
> >promising alright :-)
>
> mpc832x (e300c2 core) at 333 MHz:
>
> Before:
>
> gettimeofday: vdso: 235 nsec/call
> clock-gettime-realtime: vdso: 244 nsec/call
>
> With the series:
>
> gettimeofday: vdso: 271 nsec/call
> clock-gettime-realtime: vdso: 281 nsec/call

Those are important, and degrade ~15%. That is acceptable IMO, but do
you see a way to optimise this (later)?

Anyway, excellent results, thanks for your persistence!


Segher