NAME    [Toc]    [Back]

     madvise - give advice about use of memory

SYNOPSIS    [Toc]    [Back]

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

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

DESCRIPTION    [Toc]    [Back]

     The madvise() system call allows a process that  has  knowledge of its memory
 behavior to describe it to the system.  The possible behaviors are:

     MADV_NORMAL      No further special treatment needed.

     MADV_RANDOM      Expect random page access patterns.

     MADV_SEQUENTIAL  Expect sequential page references.

     MADV_WILLNEED    The pages will be referenced soon.

     MADV_DONTNEED    The pages will not be referenced soon.

     MADV_SPACEAVAIL  Ensure that resources are reserved.

     MADV_FREE        The pages don't contain any useful data and
can be recycled.

RETURN VALUES    [Toc]    [Back]

     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    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

     The madvise function first appeared in 4.4BSD.

OpenBSD      3.6                           June      9,      1993