[dm-devel] dm-statistics: report precise timestamps and histogram

[Bryn M. Reeves]

On Wed, Aug 19, 2015 at 06:53:41AM -0400, Mikulas Patocka wrote:
> On Tue, 18 Aug 2015, Mike Snitzer wrote:
> > On Tue, Aug 18 2015 at  4:26pm -0400,
> > Mikulas Patocka <mpatocka at redhat.com> wrote:
> > > Mike, please submit this patch to the upstream kernel before 4.2 is 
> > > released, so that the all the kernels that support the options 
> > > "precise_timestamps" and "histogram" also report these values back.
> > 
> > Userspace will have to check the DM ioctl version to know if DM provides
> > these extra keywords.
> > 
> > Mike
> 
> But if you don't send it, userspace will forever have to deal with kernels 
> that don't report this feature back.

We'd either end up saying some kernels can't support it when they can, or
have to carry some additional userspace clutter forever to provide a 
workaround.

Regards,
Bryn.