Specification Update

Specification Clarifications
Specification Update 99
Specification Clarifications
W1. Removed
See the Revision History for details.
W2. Removed
See the Revision History for details.
W3. Clarification of TRANSLATION LOOKASIDE BUFFERS (TLBS)
Invalidation
Section 10.9 INVALIDATING THE TRANSLATION LOOKASIDE BUFFERS (TLBS) of the
Intel® 64 and IA-32 Architecture Software Developer’s Manual, Volume 3A: System
Programming Guide will be modified to include the presence of page table structure
caches, such as the page directory cache, which Intel processors implement. This
information is needed to aid operating systems in managing page table structure
invalidations properly.
Intel will update the Intel® 64 and IA-32 Architecture Software Developer’s Manual,
Volume 3A: System Programming Guide in the coming months. Until that time, an
application note, TLBs, Paging-Structure Caches, and Their Invalidation
(http://www.intel.com/products/processor/manuals/index.htm), is available which provides
more information on the paging structure caches and TLB invalidation
In rare instances, improper TLB invalidation may result in unpredictable system
behavior, such as system hangs or incorrect data. Developers of operating systems
should take this documentation into account when designing TLB invalidation
algorithms. For the processors affected, Intel has provided a recommended update to
system and BIOS vendors to incorporate into their BIOS to resolve this issue.
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