---
name: "pfm_get_pmu_type"
section: "3"
platform: "linux"
package: "libpfm3-3.2-dev"
version: "3.2.070507-1.1"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/pfm_get_pmu_name"
---

# pfm\_get\_pmu\_type(3)

query library about supported PMU models

Part of [pfm\_get\_pmu\_name(3)](/pfm_get_pmu_name/3.md).

## NAME

pfm\_get\_pmu\_name, pfm\_get\_pmu\_type, pfm\_get\_pmu\_name\_bytype, pfm\_pmu\_is\_supported, pfm\_force\_pmu,pfm\_list\_supported\_pmu - query library about supported PMU models

## SYNOPSIS

```
#include <perfmon/pfmlib.h>

int pfm_get_pmu_name(char *name, int maxlen);
int pfm_get_pmu_type(int *type);
int pfm_get_pmu_name_bytype(int type, char *name, int maxlen);
int pfm_pmu_is_supported(int type);
int pfm_force_pmu(int type);
int pfm_list_supported_pmus(int (*pf)(const char *fmt,...));

```

## DESCRIPTION

These functions retrieve information about the detected host PMU and the PMU models supported by the library. More than one model can be supported by the same library.

Each PMU model is assigned a type and a name. The latter is just a string and the former is a unique identifier. The currently  supported types are:

- **PFMLIB\_GENERIC\_PMU**

  the default architected PMU model, i.e., the basic model.

- **PFMLIB\_ITANIUM\_PMU**

  the Itanium processor PMU model. The model is found in the first implementation of the IA-64 architecture, code name Merced.

- **PFMLIB\_ITANIUM2\_PMU**

  the Itanium 2 processor PMU model. This is the model provided by McKinley, Madison, and Deerfield processors.

The **pfm\_get\_pmu\_name** function returns the name of the detected  host PMU. The library must have been initialized properly before making this call. The name is returned in the **name** argument. The **maxlen** argument  indicates the maximum length of the buffer provided for **name**. Up to **maxlen-1** characters will be returned, not including the termination character.

The **pfm\_get\_pmu\_type** function returns the type of the detected host PMU. The library must have been initialized properly before making this call. The type returned in  **type** can be any one of the three listed above.

The **pfm\_get\_pmu\_name\_bytype** function returns the name of a PMU model in **name** given a type in the **type** argument. The **maxlen** argument  indicates the maximum length of the buffer provided for **name**. Up to **maxlen-1** characters will be returned, not including the termination character.

The **pfm\_pmu\_is\_supported** function returns **PFMLIB\_SUCCESS** if the given PMU type is supported by the library independently of what the host PMU model is.

The **pfm\_force\_pmu** function is used to forced the library to use a particular PMU model compared to what it has detected. The library checks that the selected  type can be supported by the host PMU. This is mostly useful to force the library to the use generic PMU model **PFMLIB\_GENERIC\_PMU**.  This function can be called at any time and upon return the library is considered initialized.

The **pfm\_list\_supported\_pmu** function is used to print the list PMU types that the library supports. The results is printed using the function provided in the **pf** argument, which must be a printf-style function.

## RETURN

The function returns whether or not it was successful. A return value of **PFMLIB\_SUCCESS** indicates success,  otherwise the value is the error code.

## ERRORS

**PFMLIB\_ERR\_NOINIT** the library has not been initialized properly.

- **PFMLIB\_ERR\_INVAL**

  invalid argument was given, most likely invalid pointer or invalid PMU type.

- **PFMLIB\_ERR\_NOTSUPP**

  the selected PMU type can be used on the host CPU.

## AUTHOR

Stephane Eranian \<eranian@hpl.hp.com\>