mincore(2) [osx man page]

MINCORE(2)						      BSD System Calls Manual							MINCORE(2)

NAME

     mincore -- determine residency of memory pages

SYNOPSIS

     #include <sys/types.h>
     #include <sys/mman.h>

     int
     mincore(caddr_t addr, size_t len, char *vec);

DESCRIPTION

     The mincore() system call allows a process to obtain information about whether pages are core resident.  The current core residency of the
     pages is returned in the character array vec.  For each entry in the character array vec, the following bit values may be set depending upon
     the state of the page:

	   MINCORE_INCORE	    0x1     /* Page is incore */
	   MINCORE_REFERENCED	    0x2     /* Page has been referenced by us */
	   MINCORE_MODIFIED	    0x4     /* Page has been modified by us */
	   MINCORE_REFERENCED_OTHER 0x8     /* Page has been referenced */
	   MINCORE_MODIFIED_OTHER  0x10     /* Page has been modified */

RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and errno is set to indicate the error.

ERRORS

     [EINVAL]		addr is not a valid address for user mode.

     [EFAULT]		an error occurred trying to copy to the output character array vec.

SEE ALSO

     madvise(2), minherit(2), mlock(2), mprotect(2), msync(2), munmap(2)

HISTORY

     The mincore() function first appeared in 4.4BSD.

BSD
								   June 9, 1993 							       BSD

MINCORE(2)						     Linux Programmer's Manual							MINCORE(2)

NAME

       mincore - get information on whether pages are in core

SYNOPSIS

       #include <unistd.h>
       #include <sys/mman.h>

       int mincore(void *start, size_t length, unsigned char *vec);

DESCRIPTION

       The  mincore  function  requests a vector describing which pages of a file are in core and can be read without disk access. The kernel will
       supply data for length bytes following the start address. On return, the kernel will have filled vec with bytes, of which the least signif-
       icant bit indicates if a page is core resident.

       For  mincore  to return successfully, start must lie on a page boundary. It is the caller's responsibility to round up to the nearest page.
       The length parameter need not be a multiple of the page size. The vector vec must be large enough to contain length/PAGE_SIZE  bytes.   One
       may obtain the page size from getpagesize(2).

RETURN VALUE

       On success, mincore returns zero.  On error, -1 is returned, and errno is set appropriately.

ERRORS

       EAGAIN kernel is temporarily out of resources

       EINVAL start is not a multiple of the page size, or len has a non-positive value

       EFAULT vec points to an invalid address

       ENOMEM address to address + length contained unmapped memory, or memory not part of a file.

BUGS

       mincore	should	return a bit vector and not a byte vector. As of Linux 2.4.5, it is not possible to gain information on the core residency
       of pages which are not backed by a file.  In other words, calling mincore on an region returned by an anonymous mmap(2) does not  work  and
       sets errno to ENOMEM. Unless pages are locked in memory, the contents of vec may be stale by the time they reach userspace.

CONFORMING TO

       mincore does not appear to be part of POSIX or the Single Unix Specification.

HISTORY

       The mincore() function first appeared in 4.4BSD.

AVAILABILITY

       Since Linux 2.3.99pre1 and glibc 2.2.

SEE ALSO

       getpagesize(2), mmap(2)

Linux 2.4.5							    2001-06-03								MINCORE(2)