[PATCH v3 8/8] perf doc: Document new IBS capabilities in man page

From: Ravi Bangoria

Date: Fri May 08 2026 - 02:13:12 EST


Include examples of
o Privilege filter with Fetch and Op PMUs, including swfilt approach on
Zen5 and older platforms and hardware assisted filter on Zen6 and newer
platforms
o Streaming store filter with Op PMU
o Fetch latency filter with Fetch PMU

Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>
---
tools/perf/Documentation/perf-amd-ibs.txt | 39 +++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/tools/perf/Documentation/perf-amd-ibs.txt b/tools/perf/Documentation/perf-amd-ibs.txt
index 548549935760..253a7375c88a 100644
--- a/tools/perf/Documentation/perf-amd-ibs.txt
+++ b/tools/perf/Documentation/perf-amd-ibs.txt
@@ -69,6 +69,14 @@ Per-cpu profile (cpu10), cycles event, sampling period: 100000

# perf record -e ibs_op// -c 100000 -C 10

+Userspace only, per-cpu profile (cpu10), cycles event, sampling period: 100000
+
+ Zen6 onward (See NOTES):
+ # perf record -e ibs_op//u -c 100000 -C 10
+
+ Until Zen5:
+ # perf record -e ibs_op/swfilt=1/u -c 100000 -C 10
+
Per-cpu profile (cpu10), cycles event, sampling freq: 1000

# perf record -e ibs_op// -F 1000 -C 10
@@ -94,6 +102,11 @@ onward)
Latency value which is a multiple of 128 incurs a little less profiling
overhead compared to other values.

+System-wide profile, cycles event, sampling period: 100000, streaming store
+filter (Zen6 onward)
+
+ # perf record -e ibs_op/strmst=1/ -c 100000 -a
+
Per process(upstream v6.2 onward), uOps event, sampling period: 100000

# perf record -e ibs_op/cnt_ctl=1/ -c 100000 -p 1234
@@ -150,6 +163,14 @@ System-wide profile, fetch ops event, sampling period: 100000

# perf record -e ibs_fetch// -c 100000 -a

+Userspace only, system-wide profile, fetch ops event, sampling period: 100000
+
+ Zen6 onward (See NOTES):
+ # perf record -e ibs_fetch//u -c 100000 -a
+
+ Until Zen5:
+ # perf record -e ibs_fetch/swfilt=1/u -c 100000 -a
+
System-wide profile, fetch ops event, sampling period: 100000, Random enable

# perf record -e ibs_fetch/rand_en=1/ -c 100000 -a
@@ -158,6 +179,15 @@ System-wide profile, fetch ops event, sampling period: 100000, Random enable
helps in cases like long running loops where PMU is tagging the same
instruction over and over because of fixed sample period.

+System-wide profile, fetch ops event, sampling period: 10000, fetch latency
+filter (Zen6 onward)
+
+ # perf record -e ibs_fetch/fetchlat=128/ -c 10000 -a
+
+ Supported fetch latency threshold values are 128 to 1920 (both inclusive).
+ Latency value which is a multiple of 128 incurs a little less profiling
+ overhead compared to other values.
+
etc.

PERF MEM AND PERF C2C
@@ -216,6 +246,15 @@ sort keys. For example:

Please refer to their man page for more detail.

+NOTES
+-----
+Hardware privilege filtering uses bit 63 to distinguish between kernel
+and userspace addresses. Hardware privilege filtering is not supported
+on 32-bit systems. Also, the bit 63 convention is not universal and can
+fail in specific environments, such as, using 64-bit host IBS to profile
+a 32-bit guest, using 64-bit host IBS to profile non-Linux 64-bit guests
+that do not adhere to the bit 63 privilege standard etc.
+
SEE ALSO
--------

--
2.43.0