[PATCH v4 02/17] sched_clock: Use seqcount instead of rolling our own

[Russell King - ARM Linux]

On Fri, Jul 19, 2013 at 10:20:19AM -0400, Nicolas Pitre wrote:
> On Fri, 19 Jul 2013, Will Deacon wrote:
> 
> > Looks good to me. The current scheme would be very fiddly to extend to
> > 64-bit values on 32-bit architectures without cheap atomic doubleword
> > accesses.
> 
> You should have a look at include/linux/cnt32_to_63.h.
> This could be applied to pure software counters if the low part is 
> atomically increased.

But this can't be used for sched_clock().  That's exactly why I originally
had to rewrite that thing in the first place.