mlockall.3p (5234B)
- '\" et
- .TH MLOCKALL "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
- .\"
- .SH PROLOG
- This manual page is part of the POSIX Programmer's Manual.
- The Linux implementation of this interface may differ (consult
- the corresponding Linux manual page for details of Linux behavior),
- or the interface may not be implemented on Linux.
- .\"
- .SH NAME
- mlockall,
- munlockall
- \(em lock/unlock the address space of a process
- (\fBREALTIME\fP)
- .SH SYNOPSIS
- .LP
- .nf
- #include <sys/mman.h>
- .P
- int mlockall(int \fIflags\fP);
- int munlockall(void);
- .fi
- .SH DESCRIPTION
- The
- \fImlockall\fR()
- function shall cause all of the pages mapped by the address space of a
- process to be memory-resident until unlocked or until the process exits
- or
- .IR exec s
- another process image. The
- .IR flags
- argument determines whether the pages to be locked are those currently
- mapped by the address space of the process, those that are mapped
- in the future, or both. The
- .IR flags
- argument is constructed from the bitwise-inclusive OR of one or more
- of the following symbolic constants, defined in
- .IR <sys/mman.h> :
- .IP MCL_CURRENT 12
- Lock all of the pages currently mapped into the address space of the
- process.
- .IP MCL_FUTURE 12
- Lock all of the pages that become mapped into the address space of the
- process in the future, when those mappings are established.
- .P
- If MCL_FUTURE is specified, and the automatic locking of future
- mappings eventually causes the amount of locked memory to exceed the
- amount of available physical memory or any other
- implementation-defined limit, the behavior is
- implementation-defined. The manner in which the implementation
- informs the application of these situations is also
- implementation-defined.
- .P
- The
- \fImunlockall\fR()
- function shall unlock all currently mapped pages of the address space
- of the process. Any pages that become mapped into the address space of
- the process after a call to
- \fImunlockall\fR()
- shall not be locked, unless there is an intervening call to
- \fImlockall\fR()
- specifying MCL_FUTURE or a subsequent call to
- \fImlockall\fR()
- specifying MCL_CURRENT. If pages mapped into the address space of the
- process are also mapped into the address spaces of other processes and
- are locked by those processes, the locks established by the other
- processes shall be unaffected by a call by this process to
- \fImunlockall\fR().
- .P
- Upon successful return from the
- \fImlockall\fR()
- function that specifies MCL_CURRENT, all currently mapped pages of the
- address space of the process shall be memory-resident and locked.
- Upon return from the
- \fImunlockall\fR()
- function, all currently mapped pages of the address space of the process
- shall be unlocked with respect to the address space of the process.
- The memory residency of unlocked pages is unspecified.
- .P
- Appropriate privileges are required to lock process memory with
- \fImlockall\fR().
- .SH "RETURN VALUE"
- Upon successful completion, the
- \fImlockall\fR()
- function shall return a value of zero. Otherwise, no additional memory
- shall be locked, and the function shall return a value of \-1 and set
- .IR errno
- to indicate the error. The effect of failure of
- \fImlockall\fR()
- on previously existing locks in the address space is unspecified.
- .P
- If it is supported by the implementation, the
- \fImunlockall\fR()
- function shall always return a value of zero. Otherwise, the function
- shall return a value of \-1 and set
- .IR errno
- to indicate the error.
- .SH ERRORS
- The
- \fImlockall\fR()
- function shall fail if:
- .TP
- .BR EAGAIN
- Some or all of the memory identified by the operation could not be
- locked when the call was made.
- .TP
- .BR EINVAL
- The
- .IR flags
- argument is zero, or includes unimplemented flags.
- .P
- The
- \fImlockall\fR()
- function may fail if:
- .TP
- .BR ENOMEM
- Locking all of the pages currently mapped into the address space of the
- process would exceed an implementation-defined limit on the amount of
- memory that the process may lock.
- .TP
- .BR EPERM
- The calling process does not have appropriate privileges to perform
- the requested operation.
- .LP
- .IR "The following sections are informative."
- .SH EXAMPLES
- None.
- .SH "APPLICATION USAGE"
- None.
- .SH RATIONALE
- None.
- .SH "FUTURE DIRECTIONS"
- None.
- .SH "SEE ALSO"
- .IR "\fIexec\fR\^",
- .IR "\fIexit\fR\^(\|)",
- .IR "\fIfork\fR\^(\|)",
- .IR "\fImlock\fR\^(\|)",
- .IR "\fImunmap\fR\^(\|)"
- .P
- The Base Definitions volume of POSIX.1\(hy2017,
- .IR "\fB<sys_mman.h>\fP"
- .\"
- .SH COPYRIGHT
- Portions of this text are reprinted and reproduced in electronic form
- from IEEE Std 1003.1-2017, Standard for Information Technology
- -- Portable Operating System Interface (POSIX), The Open Group Base
- Specifications Issue 7, 2018 Edition,
- Copyright (C) 2018 by the Institute of
- Electrical and Electronics Engineers, Inc and The Open Group.
- In the event of any discrepancy between this version and the original IEEE and
- The Open Group Standard, the original IEEE and The Open Group Standard
- is the referee document. The original Standard can be obtained online at
- http://www.opengroup.org/unix/online.html .
- .PP
- Any typographical or formatting errors that appear
- in this page are most likely
- to have been introduced during the conversion of the source files to
- man page format. To report such errors, see
- https://www.kernel.org/doc/man-pages/reporting_bugs.html .