Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
A-212 Vol. 3
PERFORMANCE-MONITORING EVENTS
2BH MMX_
INSTRUCTIONS_
EXECUTED_
V-PIPE (Counter 1)
Number of MMX
instructions executed in
the V-pipe
2CH CACHE_M-
STATE_LINE_
SHARING
(Counter 0)
Number of times a
processor identified a
hit to a modified line due
to a memory access in
the other processor
(PHITM (O))
If the average memory latencies of
the system are known, this event
enables the user to count the Write
Backs on PHITM(O) penalty and the
Latency on Hit Modified(I) penalty.
2CH CACHE_LINE_
SHARING
(Counter 1)
Number of shared data
lines in the L1 cache
(PHIT (O))
2DH EMMS_
INSTRUCTIONS_
EXECUTED (Counter
0)
Number of EMMS
instructions executed
2DH TRANSITIONS_
BETWEEN_MMX_
AND_FP_
INSTRUCTIONS
(Counter 1)
Number of transitions
between MMX and
floating-point
instructions or vice
versa
An even count indicates
the processor is in MMX
state. an odd count
indicates it is in FP state.
This event counts the first floating-
point instruction following an MMX
instruction or first MMX instruction
following a floating-point instruction.
The count may be used to estimate
the penalty in transitions between
floating-point state and MMX state.
2EH BUS_UTILIZATION_
DUE_TO_
PROCESSOR_
ACTIVITY
(Counter 0)
Number of clocks the
bus is busy due to the
processor’s own activity
(the bus activity that is
caused by the
processor)
2EH WRITES_TO_
NONCACHEABLE_
MEMORY
(Counter 1)
Number of write
accesses to
noncacheable memory
The count includes write cycles
caused by TLB misses and I/O write
cycles.
Cycles restarted due to BOFF# are
not re-counted.
Table A-19. Events That Can Be Counted with Pentium Processor
Performance-Monitoring Counters (Contd.)
Event
Num.
Mnemonic Event
Name Description Comments