520
Some
Lightweight
Profiling
Counters
Stop
Counting
When
Instruction-Based
Sampling
is
Enabled
Description
When
Lightweight
Profiling
(
LWP
)
and
Instruction-Based
Sampling
(
IBS
)
measurement
of
instruction
execution
are
simultaneously
enabled
,
the
following
LWP
counters
do
not
increment
:
•
Instructions
retired
event
counter
(
LWP
EventId
2)
•
Branches
retired
event
counter
(
LWP
EventId
3)
LWP
is
enabled
once
software
executes
a
LLWCP
or
XRSTOR
instruction
with
a
valid
LWPCB
address
.
IBS
instruction
execution
sampling
is
enabled
when
IBS
Execution
Control
[
IbsOpEn
] (
MSRC
001_1033[17])
is
1
b
.
Potential
Effect
on
System
Performance
monitoring
software
using
LWP
may
not
have
a
count
of
instructions
retired
or
branches
retired
.
Suggested
Workaround
None
.
Fix
Planned
Yes
Revision
Guide
for
AMD
Family
15
h
Models
00
h-
0
Fh
Processors
48063
Rev
. 3.18
October
2012
28
Product
Errata