pmSortInstances man page
pmSortInstances — sort performance metric values on instance identifier
void pmSortInstances(pmResult *result);
cc ... -lpcp
The routine pmSortInstances may be used to guarantee that for each performance metric in the result from pmFetch(3), the instances are in ascending instance identifier sequence.
This is most useful when trying to compute rates from two consecutive pmFetch(3) results.
PMAPI(3) and pmFetch(3).