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Diffstat (limited to 'Documentation/admin-guide/perf/starfive_starlink_pmu.rst')
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diff --git a/Documentation/admin-guide/perf/starfive_starlink_pmu.rst b/Documentation/admin-guide/perf/starfive_starlink_pmu.rst new file mode 100644 index 0000000000..2932ddb4eb --- /dev/null +++ b/Documentation/admin-guide/perf/starfive_starlink_pmu.rst @@ -0,0 +1,46 @@ +================================================ +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. |