path: root/manual/memory.texi
diff options
authorFlorian Weimer <fweimer@redhat.com>2017-11-27 17:14:29 +0100
committerFlorian Weimer <fweimer@redhat.com>2017-11-27 17:14:29 +0100
commit4bab02240e9076b49702b30bb8a1d23a0afe58cb (patch)
treefc60d42e429ae1032be1f0291145232594e1ee4e /manual/memory.texi
parenta23aa5b7272ec4a04578d82399ec2bf536281119 (diff)
Implement the mlock2 function
Fallback using mlock is provided if the flags argument is zero. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'manual/memory.texi')
1 files changed, 30 insertions, 2 deletions
diff --git a/manual/memory.texi b/manual/memory.texi
index 3f5dd902606..1b431bf5dae 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -3337,6 +3337,36 @@ The calling process is not superuser.
The kernel does not provide @code{mlock} capability.
@end table
+@end deftypefun
+@deftypefun int mlock2 (const void *@var{addr}, size_t @var{len}, unsigned int @var{flags})
+@standards{Linux, sys/mman.h}
+This function is similar to @code{mlock}. If @var{flags} is zero, a
+call to @code{mlock2} behaves exactly as the equivalent call to @code{mlock}.
+The @var{flags} argument must be a combination of zero or more of the
+following flags:
+@vtable @code
+@standards{Linux, sys/mman.h}
+Only those pages in the specified address range which are already in
+memory are locked immediately. Additional pages in the range are
+automatically locked in case of a page fault and allocation of memory.
+@end vtable
+Like @code{mlock}, @code{mlock2} returns zero on success and @code{-1}
+on failure, setting @code{errno} accordingly. Additional @code{errno}
+values defined for @code{mlock2} are:
+@table @code
+@item EINVAL
+The specified (non-zero) @var{flags} argument is not supported by this
+@end table
+@end deftypefun
You can lock @emph{all} a process' memory with @code{mlockall}. You
unlock memory with @code{munlock} or @code{munlockall}.
@@ -3346,8 +3376,6 @@ To avoid all page faults in a C program, you have to use
from the C code, e.g. the stack and automatic variables, and you
wouldn't know what address to tell @code{mlock}.
-@end deftypefun
@deftypefun int munlock (const void *@var{addr}, size_t @var{len})
@standards{POSIX.1b, sys/mman.h}