This topic describes the list of hardware counters displayed when you click Available Counters or displayed in response to the collect command.
In the counter list, "well-known" counters appear first, followed by information for all the raw hardware counters. The well-known counters are commonly used counters that have shortened alias names. The default overflow values for the well-known counters have been chosen to produce approximately the same data collection rate as for clock data. The default overflow values for raw counters will most likely select a less ideal sample rate. You should assign an overflow rate that is appropriate for your application.
The entries in the counter list for well-known counters are formatted as in the following example.
cycles[/{0|1}],9999991 ('CPU Cycles', alias for Cycle_cnt; CPU-cycles)
The first field, cycles, is the well-known counter name. The second field specifies which registers can be used for that counter. The third field, 9999991, is the default overflow value for that counter. In the fourth field, in parentheses, CPU Cycles is the metric name, followed by the raw hardware counter name, Cycle_cnt, and the type information, CPU-cycle, which specifies the type of units being counted. Type information can include up to two words. The first word of type information can be:
The second or only word of the type information can be either CPU-cycles if the counter can be used to provide a time-based metric, or events indicating that the metric is inclusive and exclusive event counts, and cannot be converted to a time
The entries in the counter list for raw (non-aliased) hardware counters are formatted as in the following example.
Cycle_cnt[/{0|1}],1000003 (CPU-cycles)
Cycle_cnt is the internal counter name used by cputrack(1). The second field specifies the registers on which the event can be counted. The third field, 1000003 is the default overflow value. The fourth field shows the counter units, which can be either CPU-cycles or events.
See also | |
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Collecting Performance Data Hardware Counter Data Programs That Use Hardware Counters |