Re: [PATCH 1/2] nohz: Select VIRT_CPU_ACCOUNTING_GEN from full dynticks config

[Ingo Molnar <mingo@kernel.org>]

* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> 2013/4/26 Frederic Weisbecker <fweisbec@gmail.com>:
> > On Fri, Apr 26, 2013 at 08:39:56AM -0700, Paul E. McKenney wrote:
> >> >  config VIRT_CPU_ACCOUNTING_GEN
> >> >     bool "Full dynticks CPU time accounting"
> >> > -   depends on HAVE_CONTEXT_TRACKING && 64BIT
> >> > +   depends on HAVE_CONTEXT_TRACKING && 64BIT && NO_HZ_FULL
> >>
> >> Do you really want this change?  This prohibits VIRT_CPU_ACCOUNTING_GEN
> >> unless NO_HZ_FULL, which means that it can no longer be used in situations
> >> where it used to be usable.  My guess is that you want to leave this
> >> particular line as it was.
> >
> > Hmm, this can make sense. This can be used to perform comparisons between
> > tick-based and tickless cputime accounting easily.
> >
> > I'll respin.
> 
> So Ingo please pull "timers/nohz-v2" instead. It does the same but
> keeps VIRT_CPU_ACCOUNTING_GEN available even without full dynticks
> (could be useful when users need something more precise than tick
> based cputime accounting.)
> 
> HEAD is 8c23b80ec7f1f5405f07bb56c2f8378800ecf401
> 
> If you've already pulled the previous branch I'll make a delta instead.
> 
> Thanks.

Pulled, thanks Frederic!

	Ingo