mincore(2)                                                       mincore(2)


   NAME
         mincore - determine residency of memory pages

   SYNOPSIS
         #include <unistd.h>
         int mincore(caddrt addr, sizet len, char *vec);

   DESCRIPTION
         mincore returns the primary memory residency status of pages in the
         address space covered by mappings in the range [addr, addr + len).
         The status is returned as a character-per-page in the character array
         referenced by *vec (which the system assumes to be large enough to
         encompass all the pages in the address range).  The least significant
         bit of each character is set to 1 to indicate that the referenced
         page is in primary memory, 0 if it is not.  The settings of other
         bits in each character are undefined and may contain other
         information in future implementations.

         mincore returns residency information that is accurate at an instant
         in time.  Because the system may frequently adjust the set of pages
         in memory, this information may quickly be outdated.  Only locked
         pages are guaranteed to remain in memory; see memcntl(2).

   RETURN VALUE
         mincore returns 0 on success, -1 on failure.

   ERRORS
         mincore fails if:

         EFAULT         *vec includes an out-of-range or otherwise
                        inaccessible address.

         EINVAL         addr is not a multiple of the page size as returned by
                        sysconf(3C).

         EINVAL         The argument len has a value less than or equal to 0.

         ENOMEM         Addresses in the range [addr, addr + len) are invalid
                        for the address space of a process, or specify one or
                        more pages which are not mapped.

   SEE ALSO
         mmap(2), mlock(3C), sysconf(3C).










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