Errata
44
Specification Update
AN84.
Some Bus Performance Monitoring Events May Not Count Local
Events under Certain Conditions
Problem:
Many Performance Monitoring Events require core-specificity, which specifies which
core’s events are to be counted (local core, other core, or both cores). Due to this
erratum, some Bus Performance Monitoring events may not count when the core-
specificity is set to the local core.
The following Bus Transaction Performance Monitor events are supposed to count all
local transactions:
•
BUS_TRANS_ IO (Event: 6CH) – Will not count I/O level reads resulting from
package resolved C-state
•
BUS_TRANS_ANY (Event: 70H) – Will not count Stop-Grants
Implication:
The count values for the affected events may be lower than expected. The degree of
under count depends on the occurrence of erratum conditions while the affected
events are active.
Workaround:
None identified.
Status:
For the steppings affected, see the
AN85.
EIP May Be Incorrect after Shutdown in IA-32e Mode
Problem:
When the processor is going into shutdown state the upper 32 bits of the instruction
pointer may be incorrect. This may be observed if the processor is taken out of
shutdown state by NMI#.
Implication:
A processor that has been taken out of the shutdown state may have an incorrect EIP.
The only software which would be affected is diagnostic software that relies on a valid
EIP.
Workaround:
None identified.
Status:
For the steppings affected, see the
AN86.
Upper 32 bits of 'From' Address Reported through BTMs or BTSs May
Be Incorrect
Problem:
When a far transfer switches the processor from 32-bit mode to IA-32e mode, the
upper 32 bits of the 'From' (source) addresses reported through the BTMs (Branch
Trace Messages) or BTSs (Branch Trace Stores) may be incorrect.
Implication:
The upper 32 bits of the 'From' address debug information reported through BTMs or
BTSs may be incorrect during this transition.
Workaround:
None identified.
Status:
