mlock(2)							System Calls Manual							  mlock(2)

NAME

       mlock() - lock a segment of the process virtual address space in memory

SYNOPSIS

DESCRIPTION

       The  system call allows the calling process to lock a segment of the process virtual address space into memory.	Any addressable segment of
       the process' address space may be locked.  Locked segments are immune to all routine swapping.

       addr must be a valid address in the process virtual address space.  addr + len must also be a valid address in the process virtual  address
       space.

       Locks  are  applied  at page boundaries that encompass the range from addr to addr + len.  If any address within the range is not valid, an
       error is returned and no locks are applied.

       or can be used to unlock memory segments (or all memory segments) locked with

       Regardless of how many times a process locks a page, a single or will unlock it.  An of a page within a range specified in an call  results
       in only the range specified in the being unlocked.

       When  memory  is shared by multiple processes and mlocks are applied to the same physical page by multiple processes, a page remains locked
       until the last lock is removed from that page.

       Locks applied with are not inherited by a child process.

       The user must have the privilege.

       Although and the family of functions may be used together in an application, each may affect the other in unexpected ways.   This  practice
       is not recommended.

   Security Restrictions
       Some  or  all of the actions associated with this system call require the privilege.  Processes owned by the superuser have this privilege.
       Processes owned by other users may have this privilege, depending on system configuration.  See privileges(5) for  more	information  about
       privileged access on systems that support fine-grained privileges.

RETURN VALUE

       returns the following values:

	      Successful completion.
	      Failure.
		     The requested operation is not performed.	is set to indicate the error.

ERRORS

       If fails, is set to one of the following values:

	      One or more addresses in the specified range is not valid within
			     the process address space.

	      There is not enough lockable memory in the system
			     to satisfy the locking request.

	      The	     parameter was zero.

	      The user does not have the
			     privilege.

EXAMPLES

       The following call to locks the first 10 pages of the calling process in memory:

SEE ALSO

       setprivgrp(1M), getprivgrp(2), mlockall(2), munlock(2), munlockall(2), plock(2), privileges(5).

STANDARDS CONFORMANCE

																	  mlock(2)