Re: [PATCH 1/5] Add a global synchronization point for pvclock
From
Peter Zijlstra <>
Date
Mon, 19 Apr 2010 12:39:05 +0200
On Fri, 2010-04-16 at 13:36 -0700, Jeremy Fitzhardinge wrote: > > + do { > > + last = last_value; > > > Does this need a barrier() to prevent the compiler from re-reading > last_value for the subsequent lines? Otherwise "(ret < last)" and > "return last" could execute with different values for "last". > ACCESS_ONCE() is your friend.