posix_madvise(3C)					   Standard C Library Functions 					 posix_madvise(3C)

NAME

       posix_madvise - memory advisory information

SYNOPSIS

       #include <sys/mman.h>

       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	optimize  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 performance
       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 characteristic 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.

       These values are defined in <sys/mman.h>

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 continuing 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 attributes:

       +-----------------------------+-----------------------------+
       |      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							    14 Jul 2008 						 posix_madvise(3C)