I
NTEL
® X
EON
® P
ROCESSOR
7500 S
ERIES
U
NCORE
P
ROGRAMMING
G
UIDE
UNCORE PERFORMANCE MONITORING
2-32
Table 2-20. B_MSR_PMON_EVT_SEL{3-0} Register – Field Definitions
The B-Box performance monitor data registers are 48b wide. A counter overflow occurs when a carry
out bit from bit 47 is detected. Software can force all uncore counting to freeze after N events by
preloading a monitor with a count value of (2
48
- 1) - N and setting the control register to send a PMI to
the U-Box. Upon receipt of the PMI, the U-Box will disable counting (
). During the interval of time between overflow and global disable, the counter value
will wrap and continue to collect events.
In this way, software can capture the precise number of events that occurred between the time uncore
counting was enabled and when it was disabled (or ‘frozen’) with minimal skew.
If accessible, software can continuously read the data registers without disabling event collection.
Table 2-21. B_MSR_PMON_CNT{3-0} Register – Field Definitions
In addition to generic event counting, each B-Box provides a MATCH/MASK register pair that allow a
user to filter packet traffic (incoming and outgoing) according to the packet Opcode, Message Class and
Physical Address. Various events can be programmed to enable a B-Box performance counter (i.e.
OPCODE_ADDR_IN_MATCH for counter 0) to capture the filter match as an event. The fields are laid out
as follows:
Note:
Table 2-103, “Intel® QuickPath Interconnect Packet Message Classes”
and
Table 2-104, “Opcode Match by Message Class”
to determine the encodings of the B-Box
Match Register fields.
Field
Bits
HW
Reset
Val
Description
ig
63
0 Read zero; writes ignored. (?)
rsv
62:61
0 Reserved; Must write to 0 else behavior is undefined.
ig
60:50
0 Read zero; writes ignored. (?)
rsv
50
0 Reserved; Must write to 0 else behavior is undefined.
ig
49:21
0 Read zero; writes ignored. (?)
pmi_en
20
0 When this bit is asserted and the corresponding counter overflows, a PMI
exception is sent to the U-Box.
ig
19:6
0 Read zero; writes ignored. (?)
ev_sel
5:1
0 Select event to be counted.
NOTE: Event selects are NOT symmetric, each counter’s event set is
different. See event section and following tables for more details.
en
0
0 Enable counter
Field
Bits
HW
Reset
Val
Description
event_count
47:0
0 48-bit performance event counter