PAPI_ipc (3) - Linux Manuals


PAPI_ipc -

Simplified call to get instructions per cycle, real and processor time.


Detailed Description

C Interface:

#include <papi.h>
int PAPI_ipc( float *rtime, float *ptime, long long *ins, float *ipc );


*rtime total realtime since the first call
*ptime total process time since the first call
*ins total instructions since the first call
*ipc incremental instructions per cycle since the last call

Return values:

PAPI_EINVAL The counters were already started by something other than PAPI_ipc().
PAPI_ENOEVNT The floating point operations event does not exist.
PAPI_ENOMEM Insufficient memory to complete the operation.

The first call to PAPI_ipc() will initialize the PAPI High Level interface, set up the counters to monitor PAPI_TOT_INS and PAPI_TOT_CYC events and start the counters.

Subsequent calls will read the counters and return total real time, total process time, total instructions since the start of the measurement and the IPC rate since the latest call to PAPI_ipc().

A call to PAPI_stop_counters() will stop the counters from running and then calls such as PAPI_start_counters() or other rate calls can safely be used.

PAPI_ipc should return a ratio greater than 1.0, indicating instruction level parallelism within the chip. The larger this ratio the more effeciently the program is running.

See Also:






Generated automatically by Doxygen for PAPI from the source code.