NAME

kinfo_getvmmap —

function for getting per-process memory map information

LIBRARY

System Utilities Library (libutil, -lutil)

SYNOPSIS

#include <sys/types.h>
#include <sys/user.h>
#include <libutil.h>

struct kinfo_vmentry *
kinfo_getvmmap(pid_t pid, int *cntp);

DESCRIPTION

This function is used for obtaining virtual memory mapping information of a particular process.

The pid field contains the process identifier. This should be the a process that you have privilege to access. The cntp field is allows the caller to know how many records are returned.

This function is a wrapper around sysctl(3) with the KERN_PROC_VMMAP mib. While the kernel returns a packed structure, this function expands the data into a fixed record format.

CAVEAT

kinfo_getvmmap() calls can cause significant CPU consumption because calculating the residency counts requires iterating over all memory pages of the process. Setting the sysctl variable kern.proc_vmmap_skip_resident_count to 1 prevents this calculation.

RETURN VALUES

On success the kinfo_getvmmap() function returns a pointer to an array of struct kinfo_vmentry structures as defined by <sys/user.h>. The array was obtained by an internal call to malloc(3) and must be freed by the caller with a call to free(3). On failure the kinfo_getvmmap() function returns NULL.

HISTORY

The kinfo_getvmmap() function first appeared in FreeBSD 7.0.