freebsd man page for pmc_get_msr

PMC_GET_MSR(3)						   BSD Library Functions Manual 					    PMC_GET_MSR(3)

NAME
     pmc_get_msr -- x86 architecture-specific PMC operations

LIBRARY
     Performance Counters Library (libpmc, -lpmc)

SYNOPSIS
     #include <pmc.h>

     int
     pmc_get_msr(pmc_id_t pmc, uint32_t *msr);

DESCRIPTION
     The function pmc_get_msr() returns the processor model specific register number associated with a PMC for subsequent use with RDPMC instruc-
     tions.  Argument pmc specifies a process scope counting PMC.  The function will write the model specific register number associated with the
     PMC to the location pointed to by argument msr.

     After successful completion of this function, applications can directly read the contents of PMC hardware using RDPMC instructions.

RETURN VALUES
     The pmc_get_msr() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to
     indicate the error.

ERRORS
     A call to pmc_get_msr() may fail with the following errors:

     [EINVAL]		The PMC handle specified was invalid.

     [EINVAL]		The PMC specified did not have process scope or counting mode.

     [EINVAL]		The PMC specified was allocated with the PMC_F_DESCENDANTS flag.

     [EINVAL]		The specified PMC is already attached to target processes other than the owner.

     [ENOSYS]		The underlying hardware does not support an RDPMC instruction.

SEE ALSO
     pmc(3), hwpmc(4)

BSD
								 November 25, 2007							       BSD