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

Table Of Contents
18-78 Vol. 3
DEBUGGING AND PERFORMANCE MONITORING
The layout of MSR_PEBS_LD_LAT_THRESHOLD is shown in Figure 18-27.
Bits 15:0 specifies the threshold load latency in core clock cycles. Performance
events with latencies greater than this value are counted in IA32_PMCx and their
latency information is reported in the PEBS record. Otherwise, they are ignored. The
minimum value that may be programmed in this field is 3.
18.17.1.3 Off-core Response Performance Monitoring in the Processor Core
Performance an event using off-core response facility can program any of the four
IA32_PERFEVTSELx MSR with specific event codes and predefine mask bit value.
Each event code for off-core response monitoring requires programming an associ-
ated configuration MSR, MSR_OFFCORE_RSP_0. There is only one off-core response
configuration MSR. Table 18-23 lists the event code, mask value and additional off-
core configuration MSR that must be programmed to count off-core response events
using IA32_PMCx.
0xC L3 MISS. Local home requests that missed the L3 cache and was serviced by local
DRAM (go to exclusive state).
0xD L3 MISS. Remote home requests that missed the L3 cache and was serviced by
remote DRAM (go to exclusive state).
0xE Reserved
0xF The request was to un-cacheable memory.
Figure 18-27. Layout of MSR_PEBS_LD_LAT MSR
Table 18-22. Data Source Encoding for Load Latency Record (Contd.)
Encoding Description
1615
0
Reserved
63
THRHLD - Load latency threshold
RESET Value — 0x00000000_00000000