PMC_INIT(3) BSD Library Functions Manual PMC_INIT(3)NAME
pmc_init -- initialize library
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include <pmc.h>
int
pmc_init(void);
DESCRIPTION
Function pmc_init() initializes the PMC library. This function must be called before any of the other functions in the library.
RETURN VALUES
The pmc_init() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
cate the error.
ERRORS
A call to pmc_init() may fail with the following errors:
[ENOENT] The hwpmc(4) module was not found in the kernel.
[EPROGMISMATCH] The library's version number did not match that expected by hwpmc(4).
[ENXIO] PMC hardware on this system is unsupported.
SEE ALSO pmc(3), hwpmc(4)BSD November 24, 2007 BSD
Check Out this Related Man Page
PMC_READ(3) BSD Library Functions Manual PMC_READ(3)NAME
pmc_read, pmc_rw, pmc_write, -- read and write hardware performance counters
LIBRARY
Performance Counters Library (libpmc, -lpmc)
SYNOPSIS
#include <pmc.h>
int
pmc_read(pmc_id_t pmc, pmc_value_t *value);
int
pmc_rw(pmc_id_t pmc, pmc_value_t newvalue, pmc_value_t *oldvaluep);
int
pmc_write(pmc_id_t pmc, pmc_value_t value);
DESCRIPTION
These functions read and write the current value of a PMC.
Function pmc_read() will read the current value of the PMC specified by argument pmc and write it to the location specified by argument
value.
Function pmc_write() will set the current value of the PMC specified by argument pmc to the value specified by argument value.
Function pmc_rw() combines a read and a write into a single atomic operation.
For write operations the PMC should be a quiescent state.
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the
error.
ERRORS
A call to these functions may fail with the following errors:
[EBUSY] A write operation specified a currently running PMC.
[EINVAL] Argument pmc specified a PMC not in a readable state.
[EINVAL] The PMC specified by argument pmc was not owned by the current process.
SEE ALSO pmc(3), hwpmc(4)BSD November 25, 2007 BSD
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