MINCORE(2) BSD System Calls Manual MINCORE(2)NAMEmincore — determine residency of memory pages
Standard C Library (libc, -lc)
mincore(const void *addr, size_t len, char *vec);
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 char‐
acter 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 &
The information returned by mincore() may be out of date by the time the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.
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
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.
SEE ALSOmadvise(2), mlock(2), mprotect(2), msync(2), munmap(2), getpagesize(3)HISTORY
The mincore() system call first appeared in 4.4BSD.
BSD January 17, 2003 BSD