This is a list of all ARM/XScale PMU1's performance counter event types. Please See Intel XScale Core Developer's Manual - Chapter 8 Performance Monitoring
| Name | Description | Counters usable | Unit mask options |
| IFU_IFETCH_MISS | number of instruction fetch misses | 1, 2 | |
| CYCLES_IFU_MEM_STALL | cycles instruction fetch pipe is stalled | 1, 2 | |
| CYCLES_DATA_STALL | cycles stall occurs for due to data dependency | 1, 2 | |
| ITLB_MISS | number of ITLB misses | 1, 2 | |
| DTLB_MISS | number of DTLB misses | 1, 2 | |
| BR_INST_EXECUTED | branch instruction executed w/ or w/o program flow change | 1, 2 | |
| BR_INST_MISS_PRED | branch mispredicted | 1, 2 | |
| INSN_EXECUTED | instruction executed | 1, 2 | |
| CYCLES_DCACHE_FULL_STALL | cycles in stall due to full dcache | 1, 2 | |
| DCACHE_FULL_STALL_CNT | number of stalls due to dcache full condition | 1 | |
| DCACHE_ACCESS | data cache access | 1, 2 | |
| DCACHE_MISS | data cache miss | 1, 2 | |
| DCACHE_WB | data cache writeback, 1 event for every half cacheline | 1, 2 | |
| PC_CHANGE | number of times the program counter was changed without a mode switch | 1, 2 | |
| BCU_REQUEST | number of time the BCU received a new memory request from the core | 1, 2 | |
| BCU_FULL | number of cycles the BCUs request queue is full | 1, 2 | |
| BCU_DRAIN | number of times the BCU queues were drained due to a Drain Write Buffer command or an I/O transaction on a non-cacheable and non-bufferable page | 1, 2 | |
| BCU_ECC_NO_ELOG | number of times the BCU detected an ECC error, but no ELOG register was available in which to log the error | 1, 2 | |
| BCU_1_BIT_ERR | number of times the BCU detected a 1-bit error while reading data from the bus | 1, 2 | |
| RMW | number of times an RMW cycle occurred due to narrow write on ECC-protected memory | 1, 2 | |
| CPU_CYCLES | clock cycles counter | 0 |
Measurement is a crucial component of performance improvement since reasoning and intuition are fallible guides and must be supplemented with tools like timing commands and profilers.- The Practice of Programming, Brian W. Kernighan and Rob Pike