.TH LIBPFM 3 "November, 2003" "" "Linux Programmer's Manual"

.SH NAME

pfm_set_options \- set performance monitoring library debug options

.SH SYNOPSIS

.nf

.B #include <perfmon/pfmlib.h>

.sp

.BI "int pfm_set_options(pfmlib_options_t *"opt);

.sp

.SH DESCRIPTION

This function can be called at any time to adjust the level

of debug of the library. In both cases, extra output will be

generated on standard error when the library gets

called. This can be useful to figure out how the PMC

registers are initialized for instance.

.sp

The opt argument to this function is a pointer to a 

.B pfmlib_options_t 

structure which is defined as follows:

.sp

.nf 

typedef struct {

	unsigned int	pfm_debug:1;

	unsigned int	pfm_verbose:1;

} pfmlib_options_t;

.fi

.sp

.sp

Setting \fBpfm_debug\fR to 1 will enable debug messages whereas setting

\fBpfm_verbose\fR will enable verbose messages. 

.SH ENVIRONMENT VARIABLES

Setting library options with this function has lower priority than

with environment variables. As such, the call to this function may

not have any actual effects. A user can set the following environment

variables to control verbosity and debug output:

.TP

.B LIBPFM_VERBOSE

Enable verbose output. Value must be 0 or 1. When not set, verbosity level

can be controlled with this function.

.TP

.B LIBPFM_DEBUG

Enable debug  output. Value must be 0 or 1. When not set, debug level

can be controlled with this function.

.LP

.SH RETURN

The function returns whether or not it was successful. A return

value of \fBPFMLIB_SUCCESS\fR indicates success, otherwise the 

value is the error code.

.sp

When environment variables exist, they take precedence and this

function returns \fBPFMLIB_SUCCESS\fR.

.SH ERRORS

.TP

.B PFMLIB_ERR_INVAL 

the argument is invalid, most likely a NULL pointer.

.SH AUTHOR

Stephane Eranian <eranian@hpl.hp.com>

.PP