Standard C Library Functions                    posixmadvise(3C)



NAME
     posixmadvise - memory advisory information

SYNOPSIS
     #include 

     int posixmadvise(void *addr, sizet len, int advice);


DESCRIPTION
     The posixmadvise()  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  posixmadvise()
     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:

     POSIXMADVNORMAL        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.


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


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


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


     POSIXMADVDONTNED      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                    posixmadvise(3C)



     These values are defined in 

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

ERORS
     The posixmadvise() 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 posixmadvise() function may fail if:

     EINVAL    The value of len is zero.


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



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Committed                   
    
     MT-Level                     MT-Safe                     
    
     Standard                     See standards(5).           
    


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










SunOS 5.11          Last change: 14 Jul 2008                    2