MINCORE(2) BSD System Calls Manual MINCORE(2)
mincore — 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 character is either 0 if the page is not resident, or a combination of the following flags (defined in <sys/mman.h>):
Page is in core (resident).
Page has been referenced by us.
Page has been modified by us.
Page has been referenced.
Page has been modified.
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The information returned by mincore() may be out of date by the time the system call returns.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.
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.
The mincore() system call will fail if:
The virtual address range specified by the addr and len arguments is not fully mapped.
The vec argument points to an illegal address.
madvise(2), mlock(2), mprotect(2), msync(2), munmap(2), getpagesize(3)
The mincore() system call first appeared in 4.4BSD.
BSD January 17, 2003 BSD