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| Cavium ThunderX2 SoC Performance Monitoring Unit (PMU UNCORE) |
| ============================================================= |
| |
| The ThunderX2 SoC PMU consists of independent, system-wide, per-socket |
| PMUs such as the Level 3 Cache (L3C), DDR4 Memory Controller (DMC) and |
| Cavium Coherent Processor Interconnect (CCPI2). |
| |
| The DMC has 8 interleaved channels and the L3C has 16 interleaved tiles. |
| Events are counted for the default channel (i.e. channel 0) and prorated |
| to the total number of channels/tiles. |
| |
| The DMC and L3C support up to 4 counters, while the CCPI2 supports up to 8 |
| counters. Counters are independently programmable to different events and |
| can be started and stopped individually. None of the counters support an |
| overflow interrupt. DMC and L3C counters are 32-bit and read every 2 seconds. |
| The CCPI2 counters are 64-bit and assumed not to overflow in normal operation. |
| |
| PMU UNCORE (perf) driver: |
| |
| The thunderx2_pmu driver registers per-socket perf PMUs for the DMC and |
| L3C devices. Each PMU can be used to count up to 4 (DMC/L3C) or up to 8 |
| (CCPI2) events simultaneously. The PMUs provide a description of their |
| available events and configuration options under sysfs, see |
| /sys/devices/uncore_<l3c_S/dmc_S/ccpi2_S/>; S is the socket id. |
| |
| The driver does not support sampling, therefore "perf record" will not |
| work. Per-task perf sessions are also not supported. |
| |
| Examples:: |
| |
| # perf stat -a -e uncore_dmc_0/cnt_cycles/ sleep 1 |
| |
| # perf stat -a -e \ |
| uncore_dmc_0/cnt_cycles/,\ |
| uncore_dmc_0/data_transfers/,\ |
| uncore_dmc_0/read_txns/,\ |
| uncore_dmc_0/write_txns/ sleep 1 |
| |
| # perf stat -a -e \ |
| uncore_l3c_0/read_request/,\ |
| uncore_l3c_0/read_hit/,\ |
| uncore_l3c_0/inv_request/,\ |
| uncore_l3c_0/inv_hit/ sleep 1 |
