MINCORE(2) |
FreeBSD System Calls Manual |
MINCORE(2) |
NAME
mincore —
determine residency of memory pages
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include < sys/mman.h>
int
mincore( const void *addr, size_t len, char *vec);
DESCRIPTION
The
mincore() system call determines whether each of the pages in the region beginning at
addr and continuing for
len bytes is resident. The status is returned in the
vec array, one character per page. Each character is either 0 if the page is not resident, or a combination of the following flags (defined in
< sys/mman.h>):
-
MINCORE_INCORE
-
Page is in core (resident).
-
MINCORE_REFERENCED
-
Page has been referenced by us.
-
MINCORE_MODIFIED
-
Page has been modified by us.
-
MINCORE_REFERENCED_OTHER
-
Page has been referenced.
-
MINCORE_MODIFIED_OTHER
-
Page has been modified.
-
MINCORE_SUPER
-
Page is part of a "super" page. (only i386 & amd64)
The information returned by mincore() may be out of date by the time the system call returns. The only way to ensure that a page is resident is to lock it into memory with the mlock(2) system call.
RETURN VALUES
The
mincore() 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
The
mincore() system call will fail if:
-
[
ENOMEM]
-
The virtual address range specified by the
addr and
len arguments is not fully mapped.
-
[
EFAULT]
-
The
vec argument points to an illegal address.
HISTORY
The
mincore() system call first appeared in
4.4BSD.