MREMAP(2)               COMMAND REFERENCE               MREMAP(2)



NAME
     mremap - remap pages of memory

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

     mremap(fromaddr, toaddr, len, prot)
     caddrt fromaddr, toaddr;
     uint len, prot;

DESCRIPTION
     Mremap causes the process pages starting at fromaddr and
     continuing for len bytes to be mapped to the address toaddr.
     The parameter prot specifies the accessibility and condition
     of the newly mapped pages.  Accessibility is specified using
     the same protection flags that were used to originally map
     the region (see mmap(2)).

     Condition is determined by two additional flags which may be
     or'ed into prot.

     M_RELEASE_ZFILL             release page resources and set to "zero-fill-on-demand"
     M_RELEASE_NFILL             release page resources and set to "provide-on-demand"

     If neither of these flags is present in prot, then the
     original contents of the pages in the mapping are maintained
     intact.  Neither of the condition flags will have any effect
     on a shared mapping.  The facility provided by the condition
     flags is more efficient than invoking munmap(2) to release
     the resources and mmap(2) to reallocate them.

     An additional condition flag may be or'ed into prot to
     eliminate the need to reestablish the permissions when
     moving or releasing a mapping.

     M_PREVIOUS          use the existing permissions


     The fromaddr, toaddr, and len parameters must be multiples
     of the system page size (obtained with the getpagesize(2)
     call), which may be larger than the underlying hardware page
     size.

DIAGNOSTICS
     [EINVAL]
         An address is not on a cluster boundary or len is not
         positive.

     [EPERM]
         The area of the object to be mapped is protected against
         the desired operation.



Printed 10/17/86                                                1

MREMAP(2)               COMMAND REFERENCE               MREMAP(2)



     [EMCOLLIDE]
         Portions of the new area are already mapped.  This check
         is made as if the old area were gone, so overlapping
         moves work.

     [EMRANGE]
         An area is outside the possible user's address space or
         includes part of the uarea.

RETURN VALUE
     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
     fmap(2), getpagesize(2), mmap(2), mremap(2), munmap(2).







































Printed 10/17/86                                                2

%%index%%
na:72,66;
sy:138,868;
de:1006,1686;
di:2692,292;3128,285;
rv:3413,236;
se:3649,220;
%%index%%000000000117