MPI\_T\_PVAR\_GET\_NUM(3) Open MPI MPI\_T\_PVAR\_GET\_NUM(3)

MPI\_T\_pvar\_get\_num — Query the number of performance variables

# [SYNTAX](#SYNTAX)

## [C Syntax](#C_Syntax)

```
#include <mpi.h>
int MPI_T_pvar_get_num(int *num_pvar)
```

# [OUTPUT PARAMETERS](#OUTPUT_PARAMETERS)

•

**num\_pvar**: Current number of performance variables.

# [DESCRIPTION](#DESCRIPTION)

MPI\_T\_pvar\_get\_num can be used to query the current number of performance variables. The number of performance variables may increase throughout the execution of the process but will never decrease.

# [ERRORS](#ERRORS)

MPI\_T\_pvar\_get\_num will fail if:

•

**MPI\_T\_ERR\_NOT\_INITIALIZED**: The MPI Tools interface not initialized

# [Copyright](#Copyright)

2003-2026, The Open MPI Community

September 16, 2026

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Document: MPI_T_pvar_get_num(3) from openmpi-cuda-12.6 5.0.11-r1 (Chainguard OS)
Source: https://github.com/open-mpi/ompi