mlockall(3C)                                                   mlockall(3C)


   NAME
         mlockall, munlockall - lock or unlock address space

   SYNOPSIS
         #include <sys/mman.h>
         int mlockall(int flags);
         int munlockall(void);

   DESCRIPTION
         The function mlockall causes all pages mapped by an address space to
         be locked in memory.  The effect of mlockall(flags) is equivalent to:

               memcntl(0, 0, MCLOCKAS, flags, 0, 0)

         The value of flags determines whether the pages to be locked are
         those currently mapped by the address space, those that will be
         mapped in the future, or both:
                        MCLCURRENT   Lock current mappings
                        MCLFUTURE    Lock future mappings

         The function munlockall removes address space locks and locks on
         mappings in the address space.  The effect of munlockall is
         equivalent to:
               memcntl(0, 0, MCUNLOCKAS, 0, 0, 0)

         Locks established with mlockall are not inherited by a child process
         after a fork and are not nested.

   RETURN VALUE
         Upon successful completion, the functions mlockall and munlockall
         return a value of 0; otherwise, they return a value of -1 and set
         errno to indicate an error.

   ERRORS
         See memcntl(2).

   NOTES
         Use of mlockall and munlockall requires that the user have
         appropriate privileges.

   SEE ALSO
         fork(2), memcntl(2), mlock(3C), mmap(2), plock(2), sysconf(3C).











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