[PATCH] Make ppc64-linux use VDSO gettimeofday instead of time syscall

[Steve Munroe]

libc-alpha-owner@sourceware.org wrote on 03/24/2010 02:21:37 PM:

>
> Re: [PATCH] Make ppc64-linux use VDSO gettimeofday instead of time
syscall
>
> Ulrich Drepper
>
> to:
>
> libc-alpha 03/24/2010 02:22 PM
> ...
>
> On 03/22/2010 07:21 AM, Carlos Eduardo Seo wrote:
> > This small patch makes ppc64 use unix/time.c, which is faster than
> > the current method. It's the same approach used by
> > sysdeps/unix/sysv/linux/sparc/sparc64.
>
> That might be the case but is it really correct?  The time() results
> don't necessarily correspond to the full seconds returned by gtod.
> There were lots of problems in this area and maybe there still are.
> This is why the x86-64 port has a separate time vsyscall.
>
What is your specific concern with correctness and this approach?
What are the specific problems you would like us to address?

As far as we can tell x86_64 vtime is using vsyscall gtod and copying
tv_sec under the covers.

Steven J. Munroe
Linux on Power Toolchain Architect
IBM Corporation, Linux Technology Center