NAME¶
MPI_Pcontrol - Controls profiling.
SYNTAX¶
C Syntax¶
#include <mpi.h>
int MPI_Pcontrol(const int level, ... )
Fortran Syntax¶
INCLUDE 'mpif.h'
MPI_PCONTROL( LEVEL)
INTEGER LEVEL
C++ Syntax¶
#include <mpi.h>
void Pcontrol(const int level, ...)
- level
- Profiling level.
DESCRIPTION¶
MPI libraries themselves make no use of this routine; they simply return
immediately to the user code. However the presence of calls to this routine
allows a profiling package to be explicitly called by the user.
Since MPI has no control of the implementation of the profiling code, we are
unable to specify precisely the semantics that will be provided by calls to
MPI_Pcontrol. This vagueness extends to the number of arguments to the
function, and their datatypes.
However to provide some level of portability of user codes to different
profiling libraries, we request the following meanings for certain values of
level:
-
o
- level==0 Profiling is disabled.
-
o
- level==1 Profiling is enabled at a normal default level of
detail.
-
o
- level==2 Profile buffers are flushed. (This may be a no-op
in some profilers).
-
o
- All other values of level have profile library-defined
effects and additional arguments.
We also request that the default state after MPI_Init has been called is for
profiling to be enabled at the normal default level (i.e., as if MPI_Pcontrol
had just been called with the argument 1). This allows users to link with a
profiling library and obtain profile output without having to modify their
source code at all.
The provision of MPI_Pcontrol as a no-op in the standard MPI library allows
users to modify their source code to obtain more detailed profiling
information, but still be able to link exactly the same code against the
standard MPI library.
NOTES¶
This routine provides a common interface for profiling control. The
interpretation of level and any other arguments is left to the profiling
library.
This function does not return an error value. Consequently, the result of
calling it before MPI_Init or after MPI_Finalize is undefined.