Re: 2.6.23-rc2-mm1: rcutorture xtime usage

Paul E. McKenney
2007-08-10T20:31:29Z

On Fri, Aug 10, 2007 at 10:12:12AM -0700, Andrew Morton wrote:
> On Fri, 10 Aug 2007 08:12:08 -0700 "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
>
> > > One used to use sched_clock() for this, then get frowned at. Now we
> > > have cpu_clock()...
> >
> > Hmmm... And cpu_clock() is not in 2.6.22, so must appear in some later
> > release. Which means that the rate of API change in this area is a
> > bit high, so I should avoid it like the plague.
>
> eh, it's been there for weeks. It is dust-encrusted.
>
> > Therefore, I should
> > look for some other convenient source of entropy.
> >
> > One convenient source would the per-CPU statistics that rcutorture
> > maintains. Of course, a given CPU's RNG is nearly in lock-step with
> > its own statistics, but not with the adjacent CPU's statistics...
> >
> > I will send a patch.
>
> Please use cpu_clock(). It ain't going away.

D'accord...

Thanx, Paul