PAPI_sprofil(3) PAPI PAPI_sprofil(3)NAMEPAPI_sprofil-
Generate PC histogram data from multiple code regions where hardware
counter overflow occurs.
SYNOPSISDetailed Description
C Interface:
#include <papi.h>
int PAPI_sprofil( PAPI_sprofil_t * prof, int profcnt, int
EventSet, int EventCode, int threshold, int flags );
Parameters:
*prof pointer to an array of PAPI_sprofil_t structures. Each copy
of the structure contains the following:
· buf -- pointer to a buffer of bufsiz bytes in which the histogram
counts are stored in an array of unsigned short, unsigned int, or
unsigned long long values, or 'buckets'. The size of the buckets
is determined by values in the flags argument.
· bufsiz -- the size of the histogram buffer in bytes. It is
computed from the length of the code region to be profiled, the
size of the buckets, and the scale factor as discussed below.
· offset -- the start address of the region to be profiled.
· scale -- broadly and historically speaking, a contraction factor
that indicates how much smaller the histogram buffer is than the
region to be profiled. More precisely, scale is interpreted as an
unsigned 16-bit fixed-point fraction with the decimal point
implied on the left. Its value is the reciprocal of the number of
addresses in a subdivision, per counter of histogram buffer.
profcnt number of structures in the prof array for hardware
profiling.
EventSet The PAPI EventSet to profile. This EventSet is marked as
profiling-ready, but profiling doesn't actually start until a
PAPI_start() call is issued.
EventCode Code of the Event in the EventSet to profile. This event
must already be a member of the EventSet.
threshold minimum number of events that must occur before the PC is
sampled. If hardware overflow is supported for your component, this
threshold will trigger an interrupt when reached. Otherwise, the
counters will be sampled periodically and the PC will be recorded
for the first sample that exceeds the threshold. If the value of
threshold is 0, profiling will be disabled for this event.
flags bit pattern to control profiling behavior. Defined values are
given in a table in the documentation for PAPI_pofil
Return values:
Return values for PAPI_sprofil() are identical to those for
PAPI_profil. Please refer to that page for further details.
PAPI_sprofil() is a structure driven profiler that profiles one or more
disjoint regions of code in a single call. It accepts a pointer to a
preinitialized array of sprofil structures, and initiates profiling
based on the values contained in the array. Each structure in the array
defines the profiling parameters that are normally passed to
PAPI_profil(). For more information on profiling, PAPI_profil
Example:
int retval;
unsigned long length;
PAPI_exe_info_t *prginfo;
unsigned short *profbuf1, *profbuf2, profbucket;
PAPI_sprofil_t sprof[3];
prginfo = PAPI_get_executable_info();
if (prginfo == NULL) handle_error( NULL );
length = (unsigned long)(prginfo->text_end - prginfo->text_start);
// Allocate 2 buffers of equal length
profbuf1 = (unsigned short *)malloc(length);
profbuf2 = (unsigned short *)malloc(length);
if ((profbuf1 == NULL) || (profbuf2 == NULL))
handle_error( NULL );
memset(profbuf1,0x00,length);
memset(profbuf2,0x00,length);
// First buffer
sprof[0].pr_base = profbuf1;
sprof[0].pr_size = length;
sprof[0].pr_off = (caddr_t) DO_FLOPS;
sprof[0].pr_scale = 0x10000;
// Second buffer
sprof[1].pr_base = profbuf2;
sprof[1].pr_size = length;
sprof[1].pr_off = (caddr_t) DO_READS;
sprof[1].pr_scale = 0x10000;
// Overflow bucket
sprof[2].pr_base = profbucket;
sprof[2].pr_size = 1;
sprof[2].pr_off = 0;
sprof[2].pr_scale = 0x0002;
retval = PAPI_sprofil(sprof, EventSet, PAPI_FP_INS, 1000000,
PAPI_PROFIL_POSIX | PAPI_PROFIL_BUCKET_16)) != PAPI_OK)
if ( retval != PAPI_OK ) handle_error( retval );
See also:
PAPI_overflow
PAPI_get_executable_info
PAPI_profil
Author
Generated automatically by Doxygen for PAPI from the source code.
Version 5.1.1.0 Tue May 21 2013 PAPI_sprofil(3)
