This version (2022/06/20 09:01) was approved by msiegel.
This is an old revision of the document!
Interfacing with PAPI : Low level interface for C
#include <stdio.h> #include <stdlib.h> #include "papi.h" main() { // PAPI variables // best is to analyze one particular event at a time int eventset; long long value, time0, time1, cyc0, cyc1; // PAPI Initialization eventset = PAPI_NULL; if (PAPI_library_init(PAPI_VER_CURRENT) != PAPI_VER_CURRENT) { printf("PAPI init error !\n"); exit(993); } // PAPI Event Set Creation if (PAPI_create_eventset(&eventset) != PAPI_OK) { printf("PAPI event set creation error !\n"); exit(994); } // PAPI Specify a Particular Target Event to Analyze // PAPI_TOT_CYC Total cycles executed // PAPI_FP_OPS Floating point operations executed // PAPI_L1_DCM Level 1 data cache misses // PAPI_L2_DCM Level 2 data cache misses // for other events see /opt/sw/x86_64/glibc-2.12/ivybridge-ep/papi/5.4.3/gnu-4.4.7/include/papiStdEventDefs.h // if (PAPI_add_event(eventset, PAPI_FP_OPS) != PAPI_OK) { printf("PAPI event set adding error !\n"); exit(995); } // PAPI Time Estimators Initialization time0 = PAPI_get_real_usec(); cyc0 = PAPI_get_real_cyc(); // PAPI Counting Start if (PAPI_start(eventset) != PAPI_OK) { printf("PAPI start error !\n"); exit(996); } //*** Here follows the original code section to be analyzed *** // PAPI Counting Stop if (PAPI_stop(eventset, &value) != PAPI_OK) { printf("PAPI stop error !\n"); exit(997); } // PAPI Time Estimators Stop time1 = PAPI_get_real_usec(); cyc1 = PAPI_get_real_cyc(); // PAPI Results printf("PAPI event count %lld\n", value); printf("PAPI time passed in usec %lld\n", time1 - time0); printf("PAPI cycles passed %lld\n", cyc1 - cyc0); // PAPI Free Event Set if (PAPI_cleanup_eventset(eventset) != PAPI_OK) { printf("PAPI event set cleanup error !\n"); exit(998); } if (PAPI_destroy_eventset(&eventset) != PAPI_OK) { printf("PAPI event set destruction error !\n"); exit(999); } // PAPI Finalize PAPI_shutdown(); }