NAME    [Toc]    [Back]

     madvise - give advice about use of memory

LIBRARY    [Toc]    [Back]

     Standard C Library (libc, -lc)

SYNOPSIS    [Toc]    [Back]

     #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 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       /* ensure that resources are reserved */
     #define MADV_FREE       6       /* pages are empty, free them */

SEE ALSO    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

     The madvise system call first appeared in 4.4BSD, but until NetBSD 1.5 it
     did not perform any of the requests on, or change any behavior of the
     address range given.

BSD                              June 9, 1993                              BSD