Start counting hardware events in an event set.
C Interface:
#include <papi.h>
int PAPI_start( int EventSet );
Parameters:
EventSet -- an integer handle for a PAPI event set as created by PAPI_create_eventset
Return values:
PAPI_OK
PAPI_EINVAL -- One or more of the arguments is invalid.
PAPI_ESYS -- A system or C library call failed inside PAPI, see the errno variable.
PAPI_ENOEVST -- The EventSet specified does not exist.
PAPI_EISRUN -- The EventSet is currently counting events.
PAPI_ECNFLCT -- The underlying counter hardware can not count this event and other events in the EventSet simultaneously.
PAPI_ENOEVNT -- The PAPI preset is not available on the underlying hardware.
PAPI_start starts counting all of the hardware events contained in the previously defined EventSet. All counters are implicitly set to zero before counting. Assumes an initialized PAPI library and a properly added event set.
Example:
* int EventSet = PAPI_NULL; * long long values[2]; * int ret; * * ret = PAPI_create_eventset(&EventSet); * if (ret != PAPI_OK) handle_error(ret); * * // Add Total Instructions Executed to our EventSet * ret = PAPI_add_event(EventSet, PAPI_TOT_INS); * if (ret != PAPI_OK) handle_error(ret); * * // Start counting * ret = PAPI_start(EventSet); * if (ret != PAPI_OK) handle_error(ret); * poorly_tuned_function(); * ret = PAPI_stop(EventSet, values); * if (ret != PAPI_OK) handle_error(ret); * printf("%lld\n",values[0]); *
See Also:
PAPI_create_eventset PAPI_add_event PAPI_stop
Generated automatically by Doxygen for PAPI from the source code.