mirror of
https://github.com/torvalds/linux.git
synced 2024-11-21 19:41:42 +00:00
49925c1c5a
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>
47 lines
1.8 KiB
ReStructuredText
47 lines
1.8 KiB
ReStructuredText
================================================
|
|
StarFive StarLink Performance Monitor Unit (PMU)
|
|
================================================
|
|
|
|
StarFive StarLink Performance Monitor Unit (PMU) exists within the
|
|
StarLink Coherent Network on Chip (CNoC) that connects multiple CPU
|
|
clusters with an L3 memory system.
|
|
|
|
The uncore PMU supports overflow interrupt, up to 16 programmable 64bit
|
|
event counters, and an independent 64bit cycle counter.
|
|
The PMU can only be accessed via Memory Mapped I/O and are common to the
|
|
cores connected to the same PMU.
|
|
|
|
Driver exposes supported PMU events in sysfs "events" directory under::
|
|
|
|
/sys/bus/event_source/devices/starfive_starlink_pmu/events/
|
|
|
|
Driver exposes cpu used to handle PMU events in sysfs "cpumask" directory
|
|
under::
|
|
|
|
/sys/bus/event_source/devices/starfive_starlink_pmu/cpumask/
|
|
|
|
Driver describes the format of config (event ID) in sysfs "format" directory
|
|
under::
|
|
|
|
/sys/bus/event_source/devices/starfive_starlink_pmu/format/
|
|
|
|
Example of perf usage::
|
|
|
|
$ perf list
|
|
|
|
starfive_starlink_pmu/cycles/ [Kernel PMU event]
|
|
starfive_starlink_pmu/read_hit/ [Kernel PMU event]
|
|
starfive_starlink_pmu/read_miss/ [Kernel PMU event]
|
|
starfive_starlink_pmu/read_request/ [Kernel PMU event]
|
|
starfive_starlink_pmu/release_request/ [Kernel PMU event]
|
|
starfive_starlink_pmu/write_hit/ [Kernel PMU event]
|
|
starfive_starlink_pmu/write_miss/ [Kernel PMU event]
|
|
starfive_starlink_pmu/write_request/ [Kernel PMU event]
|
|
starfive_starlink_pmu/writeback/ [Kernel PMU event]
|
|
|
|
|
|
$ perf stat -a -e /starfive_starlink_pmu/cycles/ sleep 1
|
|
|
|
Sampling is not supported. As a result, "perf record" is not supported.
|
|
Attaching to a task is not supported, only system-wide counting is supported.
|