Manual Pages for UNIX Operating System command usage for man posix_madvise

Standard C Library Functions                    posix_madvise(3C)



NAME
     posix_madvise - memory advisory information

SYNOPSIS
     #include 

     int posix_madvise(void *addr, size_t len, int advice);


DESCRIPTION
     The posix_madvise()  function  advises  the  system  on  the
     expected  behavior  of  the  application with respect to the
     data in the memory starting at address addr, and  continuing
     for len bytes. The system may use this information to optim-
     ize handling of  the  specified  data.  The  posix_madvise()
     function  has no effect on the semantics of access to memory
     in the specified range, although it may affect  the  perfor-
     mance of access.


     The advice to be applied to the memory range is specified by
     the advice parameter and may be one of the following values:

     POSIX_MADV_NORMAL        Specifies that the application  has
                              no  advice  to give on its behavior
                              with  respect  to   the   specified
                              range.  It  is  the default charac-
                              teristic if no advice is given  for
                              a range of memory.


     POSIX_MADV_SEQUENTIAL    Specifies  that   the   application
                              expects  to  access  the  specified
                              range   sequentially   from   lower
                              addresses to higher addresses.


     POSIX_MADV_RANDOM        Specifies  that   the   application
                              expects  to  access  the  specified
                              range in a random order.


     POSIX_MADV_WILLNEED      Specifies  that   the   application
                              expects  to  access  the  specified
                              range in the near future.


     POSIX_MADV_DONTNEED      Specifies  that   the   application
                              expects that it will not access the
                              specified range in the near future.





SunOS 5.11          Last change: 14 Jul 2008                    1






Standard C Library Functions                    posix_madvise(3C)



     These values are defined in 

RETURN VALUES
     Upon successful completion,  posix_madvise()  returns  zero.
     Otherwise,  an  error  number  is  returned  to indicate the
     error.

ERRORS
     The posix_madvise() function will fail if:

     EINVAL    The value of advice is invalid.


     ENOMEM    Addresses in the range starting at addr  and  con-
               tinuing  for  len  bytes  are partly or completely
               outside the range allowed for the address space of
               the calling process.



     The posix_madvise() function may fail if:

     EINVAL    The value of len is zero.


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     mmap(2),  madvise(3C),   posix_madvise(3C),   attributes(5),
     standards(5)










SunOS 5.11          Last change: 14 Jul 2008                    2