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

Table Of Contents
Vol. 3 A-203
PERFORMANCE-MONITORING EVENTS
Segment
Register
Renaming
D4H SEG_RENAME_
STALLS
Number of Segment
Register Renaming Stalls:
Available in Pentium
II and Pentium
III
processors only.
02H
04H
08H
0FH
Segment register ES
Segment register DS
Segment register FS
Segment register FS
Segment registers
ES + DS + FS + GS
D5H SEG_REG_
RENAMES
Number of Segment
Register Renames:
Available in Pentium
II and Pentium
III
processors only.
01H
02H
04H
08H
0FH
Segment register ES
Segment register DS
Segment register FS
Segment register FS
Segment registers
ES + DS + FS + GS
D6H RET_SEG_
RENAMES
00H Number of segment
register rename events
retired.
Available in Pentium
II and Pentium
III
processors only.
NOTES:
1. Several L2 cache events, where noted, can be further qualified using the Unit Mask (UMSK) field
in the PerfEvtSel0 and PerfEvtSel1 registers. The lower 4 bits of the Unit Mask field are used in
conjunction with L2 events to indicate the cache state or cache states involved.
The P6 family processors identify cache states using the “MESI” protocol and consequently each
bit in the Unit Mask field represents one of the four states: UMSK[3] = M (8H) state, UMSK[2] = E
(4H) state, UMSK[1] = S (2H) state, and UMSK[0] = I (1H) state. UMSK[3:0] = MESI” (FH) should be
used to collect data for all states; UMSK = 0H, for the applicable events, will result in nothing
being counted.
2. All of the external bus logic (EBL) events, except where noted, can be further qualified using the
Unit Mask (UMSK) field in the PerfEvtSel0 and PerfEvtSel1 registers.
Bit 5 of the UMSK field is used in conjunction with the EBL events to indicate whether the pro-
cessor should count transactions that are self- generated (UMSK[5] = 0) or transactions that
result from any processor on the bus (UMSK[5] = 1).
3. L2 cache locks, so it is possible to have a zero count.
Table A-18. Events That Can Be Counted with the P6 Family Performance-
Monitoring Counters (Contd.)
Unit
Event
Num.
Mnemonic Event
Name
Unit
Mask Description Comments