K 10
svn:author
V 3
jhb
K 8
svn:date
V 27
2010-01-26T20:58:09.668569Z
K 7
svn:log
V 767
MFC 195820, 195940, 196643, 197663, 199067, 199215, and 199253:
Optimize the cache flushing done when changing caching attributes of pages
by doing nothing for CPUs that support self-snooping and using CLFLUSH
instead of a full cache invalidate when possible.
- On i386 take care of possible mappings of the page by sf buffer by
  utilizing the mapping for clflush, otherwise map the page transiently.
  Amd64 uses the direct map.
- Do not use CLFLUSH on Intel CPUs due to problems with flushing the local
  APIC range by default.  This can be further controlled via the
  hw.clflush_disable loader tunable.  A setting of 1 disables the
  use of CLFLUSH.  A setting of 0 allows CLFLUSH to be used for Intel
  CPUs when CPUID_SS is not present.

Approved by:	re (kib)

END