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| -rw-r--r-- | Documentation/perf/hisi-pmu.txt | 53 |
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diff --git a/Documentation/perf/hisi-pmu.txt b/Documentation/perf/hisi-pmu.txt new file mode 100644 index 000000000000..267a028b2741 --- /dev/null +++ b/Documentation/perf/hisi-pmu.txt @@ -0,0 +1,53 @@ +HiSilicon SoC uncore Performance Monitoring Unit (PMU) +====================================================== +The HiSilicon SoC chip includes various independent system device PMUs +such as L3 cache (L3C), Hydra Home Agent (HHA) and DDRC. These PMUs are +independent and have hardware logic to gather statistics and performance +information. + +The HiSilicon SoC encapsulates multiple CPU and IO dies. Each CPU cluster +(CCL) is made up of 4 cpu cores sharing one L3 cache; each CPU die is +called Super CPU cluster (SCCL) and is made up of 6 CCLs. Each SCCL has +two HHAs (0 - 1) and four DDRCs (0 - 3), respectively. + +HiSilicon SoC uncore PMU driver +--------------------------------------- +Each device PMU has separate registers for event counting, control and +interrupt, and the PMU driver shall register perf PMU drivers like L3C, +HHA and DDRC etc. The available events and configuration options shall +be described in the sysfs, see : +/sys/devices/hisi_sccl{X}_<l3c{Y}/hha{Y}/ddrc{Y}>/, or +/sys/bus/event_source/devices/hisi_sccl{X}_<l3c{Y}/hha{Y}/ddrc{Y}>. +The "perf list" command shall list the available events from sysfs. + +Each L3C, HHA and DDRC is registered as a separate PMU with perf. The PMU +name will appear in event listing as hisi_sccl<sccl-id>_module<index-id>. +where "sccl-id" is the identifier of the SCCL and "index-id" is the index of +module. +e.g. hisi_sccl3_l3c0/rd_hit_cpipe is READ_HIT_CPIPE event of L3C index #0 in +SCCL ID #3. +e.g. hisi_sccl1_hha0/rx_operations is RX_OPERATIONS event of HHA index #0 in +SCCL ID #1. + +The driver also provides a "cpumask" sysfs attribute, which shows the CPU core +ID used to count the uncore PMU event. + +Example usage of perf: +$# perf list +hisi_sccl3_l3c0/rd_hit_cpipe/ [kernel PMU event] +------------------------------------------ +hisi_sccl3_l3c0/wr_hit_cpipe/ [kernel PMU event] +------------------------------------------ +hisi_sccl1_l3c0/rd_hit_cpipe/ [kernel PMU event] +------------------------------------------ +hisi_sccl1_l3c0/wr_hit_cpipe/ [kernel PMU event] +------------------------------------------ + +$# perf stat -a -e hisi_sccl3_l3c0/rd_hit_cpipe/ sleep 5 +$# perf stat -a -e hisi_sccl3_l3c0/config=0x02/ sleep 5 + +The current driver does not support sampling. So "perf record" is unsupported. +Also attach to a task is unsupported as the events are all uncore. + +Note: Please contact the maintainer for a complete list of events supported for +the PMU devices in the SoC and its information if needed. |