tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
docs: perf: Add description for StarFive's StarLink PMU
StarFive StarLink PMU support monitoring L3 memory system PMU events.
Add documentation to describe StarFive StarLink PMU support and it's
usage.
Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
Link: https://lore.kernel.org/r/20240229072720.3987876-4-jisheng.teoh@starfivetech.com
Signed-off-by: Will Deacon <will@kernel.org>
authored by
Ji Sheng Teoh
and committed by
Will Deacon
49925c1c
66461b43
+47
+1
Documentation/admin-guide/perf/index.rst
+1
Documentation/admin-guide/perf/index.rst
+46
Documentation/admin-guide/perf/starfive_starlink_pmu.rst
+46
Documentation/admin-guide/perf/starfive_starlink_pmu.rst
···
1
+
================================================
2
+
StarFive StarLink Performance Monitor Unit (PMU)
3
+
================================================
4
+
5
+
StarFive StarLink Performance Monitor Unit (PMU) exists within the
6
+
StarLink Coherent Network on Chip (CNoC) that connects multiple CPU
7
+
clusters with an L3 memory system.
8
+
9
+
The uncore PMU supports overflow interrupt, up to 16 programmable 64bit
10
+
event counters, and an independent 64bit cycle counter.
11
+
The PMU can only be accessed via Memory Mapped I/O and are common to the
12
+
cores connected to the same PMU.
13
+
14
+
Driver exposes supported PMU events in sysfs "events" directory under::
15
+
16
+
/sys/bus/event_source/devices/starfive_starlink_pmu/events/
17
+
18
+
Driver exposes cpu used to handle PMU events in sysfs "cpumask" directory
19
+
under::
20
+
21
+
/sys/bus/event_source/devices/starfive_starlink_pmu/cpumask/
22
+
23
+
Driver describes the format of config (event ID) in sysfs "format" directory
24
+
under::
25
+
26
+
/sys/bus/event_source/devices/starfive_starlink_pmu/format/
27
+
28
+
Example of perf usage::
29
+
30
+
$ perf list
31
+
32
+
starfive_starlink_pmu/cycles/ [Kernel PMU event]
33
+
starfive_starlink_pmu/read_hit/ [Kernel PMU event]
34
+
starfive_starlink_pmu/read_miss/ [Kernel PMU event]
35
+
starfive_starlink_pmu/read_request/ [Kernel PMU event]
36
+
starfive_starlink_pmu/release_request/ [Kernel PMU event]
37
+
starfive_starlink_pmu/write_hit/ [Kernel PMU event]
38
+
starfive_starlink_pmu/write_miss/ [Kernel PMU event]
39
+
starfive_starlink_pmu/write_request/ [Kernel PMU event]
40
+
starfive_starlink_pmu/writeback/ [Kernel PMU event]
41
+
42
+
43
+
$ perf stat -a -e /starfive_starlink_pmu/cycles/ sleep 1
44
+
45
+
Sampling is not supported. As a result, "perf record" is not supported.
46
+
Attaching to a task is not supported, only system-wide counting is supported.