Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 644

PAL_GET_PSTATE
PAL_GET_PSTATE – Return Information on the Performance Index
of the Processor (262)
Returns the performance index of the processor.
Purpose:
Stacked Registers
Calling Conv:
Physical and Virtual
Mode:
Dependent
Buffer:
Arguments:
Argument
index
type
Reserved
Reserved
Returns:
Return Value
status
performance_index
Reserved
Reserved
Status:
Status Value
1
0
-1
-2
-3
-9
This procedure returns a performance index of the processor, and is relative to the
Description:
highest available P-state, P0. A value of 100 represents the minimum processor
performance in the P0 state. For processors that support variable P-state performance,
it is possible for a processor to report a number greater than 100, representing that the
processor is running at a performance level greater than the minimum P0 performance.
The PAL procedure
(17)" on page 2:446
performance.
The type argument allows the caller to select the performance_index value that will be
returned. See
2:396
Description
Index of PAL_GET_PSTATE within the list of PAL procedures.
Type of performance_index value to be returned by this procedure.
0
0
Description
Return status of the PAL_GET_PSTATE procedure.
Unsigned integer denoting the processor performance for the time duration since the
last PAL_GET_PSTATE procedure call was made. The value returned is relative to the
performance index of the highest available P-state.
0
0
Description
Call completed without error, but accuracy of performance index has been impacted by a
thermal throttling event, or a hardware-initiated event.
Call completed without error
Unimplemented procedure
Invalid argument
Call completed with error
Call requires PAL memory buffer
"PAL_PROC_GET_FEATURES – Get Processor Dependent Features
indicates whether the processor supports variable P-state
Table 11-81 below for details.
Volume 2, Part 1: Processor Abstraction Layer