I
NTEL
® X
EON
® P
ROCESSOR
7500 S
ERIES
U
NCORE
P
ROGRAMMING
G
UIDE
UNCORE PERFORMANCE MONITORING
2-3
a) Clear all uncore counters: Set U_MSR_PMON_GLOBAL_CTL.rst_all to 1.
b) Clear all overflow bits. When an overflow bit is cleared, all bits that summarize that overflow (above
in the hierarchy) will also be cleared. Therefore it is only necessary to clear the overflow bits
corresponding to the actual counter.
i.e. If counter 3 in B-Box 1 overflowed, to clear the overflow bit software should set
B_MSR_PMON_GLOBAL_OVF_CTL.clr_ov[3] to 1 in B-Box 1. This action will also clear
S_MSR_PMON_SUMMARY.ov_mb in S-Box 1 and U_MSR_PMON_GLOBAL_STATUS.ov_s1.c
c) Create the next sample: Reinitialize the sample by setting the monitoring data register to (2^48 -
sample_interval). Or set up a new sample interval as outlined in
Section 2.1.2, “Setting up a Monitoring
d) Re-enable counting: Set U_MSR_PMON_GLOBAL_CTL.en_all to 1. Set the .rst_all field back to 0 with
the same write.
2.1.5
Global Performance Monitors
Table 2-1. Global Performance Monitoring Control MSRs
2.1.5.1
Global PMON Global Control/Status Registers
The following registers represent state governing all PMUs in the uncore, both to exert global control
and collect box-level information.
U_MSR_PMON_GLOBAL_CTL contains bits that can reset (.rst_all) and freeze/enable (.en_all) all the
uncore counters. The .en_all bit must be set to 1 before any uncore counters will collect events.
Note:
The register also contains the enable for the U-Box counters.
If an overflow is detected in any of the uncore’s PMON registers, it will be summarized in
U_MSR_PMON_GLOBAL_STATUS. This register accumulates overflows sent to it from the U-Box, W-Box
and S-Boxes and indicates if a disable was received from one of the boxes. To reset the summary
overflow bits, a user must set the corresponding bits in the U_MSR_PMON_GLOBAL_OVF_CTL register.
MSR Name
Access
MSR
Address
Size
(bits)
Description
U_MSR_PMON_GLOBAL_OVF_CTL
RW_RW
0x0C02
32 U-Box PMON Global Overflow Control
U_MSR_PMON_GLOBAL_STATUS
RW_RO
0x0C01
32 U-Box PMON Global Status
U_MSR_PMON_GLOBAL_CTL
RW_RO
0x0C00
32 U-Box PMON Global Control