From: Martin Hicks <mort@wildopensource.com>

This is a patch based on one that Jack Steiner sent to the ia64 list in
November.  The original thread can be found at:

http://marc.theaimsgroup.com/?l=linux-ia64&m=106869606922555&w=2

I created the little wrapper function that was requested.  I think the only
other arch, other than ia64, that doesn't at least include asm-generic/tlb.h
is arm.


Something appears broken in TLB flushing on IA64 (& possibly other
architectures).  Functionally, it works but performance is bad on systems
with large cpu counts.

The result is that TLB flushing in exit_mmap() is frequently being done via
IPIs to all cpus rather than with a "ptc" instruction or with a new
context..