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

From: Segher Boessenkool <[email-masked]>
Date: Mon, 20 Jan 2020 09:19:36 -0600

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