On Wed, May 25, 2011 at 3:26 AM, Andrew Haley <a...@redhat.com> wrote: > On 05/24/2011 07:28 PM, H.J. Lu wrote: > >> This patch implements pause intrinsic suggested by Andi. OK >> for trunk? > > What does "full memory barrier" here mean? > > +@table @code > +@item void __builtin_ia32_pause (void) > +Generates the @code{pause} machine instruction with full memory barrier. > +@end table > > There a memory clobber, but no barrier instruction AFAICS. The > doc needs to explain it a bit better. >
There are read/load memory barrier, write/store memory barrier and full/general memory barrier. You can find them at http://www.kernel.org/doc/Documentation/memory-barriers.txt Should I include a pointer to it? -- H.J.