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

Table Of Contents
18-74 Vol. 3
DEBUGGING AND PERFORMANCE MONITORING
PEBS Index: This field is initially programmed with the same value as the PEBS
Buffer Base field, or the beginning linear address of the PEBS buffer. The
processor reads this field to determine the location of the next PEBS record to
write to. After a PEBS record has been written, the processor also updates this
field with the address of the next PEBS record to be written. The figure above
illustrates the state of PEBS Index after the first PEBS record is written.
PEBS Absolute Maximum: This field represents the absolute address of the
maximum length of the allocated PEBS buffer plus the starting address of the
PEBS buffer. The processor will not write any PEBS record beyond the end of
PEBS buffer, when PEBS Index equals PEBS Absolute Maximum. No signaling
Figure 18-26. PEBS Programming Environment
BTS Buffer Base
BTS Index
BTS Absolute
BTS Interrupt
PEBS Absolute
PEBS Interrupt
PEBS
Maximum
Maximum
Threshold
PEBS Index
PEBS Buffer Base
Threshold
Counter0 Reset
Reserved
0H
8H
10H
18H
20H
28H
30H
38H
40H
48H
50H
Branch Record 0
Branch Record 1
Branch Record n
PEBS Record 0
PEBS Record 1
PEBS Record n
BTS Buffer
PEBS Buffer
DS Buffer Management Area
IA32_DS_AREA MSR
58H
60H
PEBS
Counter1 Reset
PEBS
Counter2 Reset
PEBS
Counter3 Reset