MADVISE(2)                OpenBSD Programmer's Manual               MADVISE(2)

NAME
     madvise - give advice about use of memory



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

     int
     madvise(void *addr, size_t len, int behav);

DESCRIPTION
     The madvise() system call allows a process that has knowledge of its mem-
     ory behavior to describe it to the system.  The known behaviors are given
     in <sys/mman.h>:

     #define MADV_NORMAL     0       /* no further special treatment */
     #define MADV_RANDOM     1       /* expect random page references */
     #define MADV_SEQUENTIAL 2       /* expect sequential references */
     #define MADV_WILLNEED   3       /* will need these pages */
     #define MADV_DONTNEED   4       /* don't need these pages */
     #define MADV_SPACEAVAIL 5       /* insure that resources are reserved */

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.

SEE ALSO
     mincore(2),  minherit(2),  mprotect(2),  msync(2),  munmap(2)

BUGS
     The madvise() function is not implemented in the current vm subsystem.

HISTORY
     The madvise function first appeared in 4.4BSD.

OpenBSD 2.6                      June 9, 1993                                1