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Diffstat (limited to 'lib/libc/sys/msync.2')
-rw-r--r-- | lib/libc/sys/msync.2 | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/lib/libc/sys/msync.2 b/lib/libc/sys/msync.2 new file mode 100644 index 0000000..cb15925 --- /dev/null +++ b/lib/libc/sys/msync.2 @@ -0,0 +1,121 @@ +.\" Copyright (c) 1991, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)msync.2 8.2 (Berkeley) 6/21/94 +.\" $FreeBSD$ +.\" +.Dd June 21, 1994 +.Dt MSYNC 2 +.Os +.Sh NAME +.Nm msync +.Nd synchronize a mapped region +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In sys/mman.h +.Ft int +.Fn msync "void *addr" "size_t len" "int flags" +.Sh DESCRIPTION +The +.Fn msync +system call +writes any modified pages back to the file system and updates +the file modification time. +If +.Fa len +is 0, all modified pages within the region containing +.Fa addr +will be flushed; +if +.Fa len +is non-zero, only those pages containing +.Fa addr +and +.Fa len-1 +succeeding locations will be examined. +The +.Fa flags +argument may be specified as follows: +.Pp +.Bl -tag -width ".Dv MS_INVALIDATE" -compact +.It Dv MS_ASYNC +Return immediately +.It Dv MS_SYNC +Perform synchronous writes +.It Dv MS_INVALIDATE +Invalidate all cached data +.El +.Sh RETURN VALUES +.Rv -std msync +.Sh ERRORS +The +.Fn msync +system call +will fail if: +.Bl -tag -width Er +.It Bq Er EBUSY +Some or all of the pages in the specified region are locked and +.Dv MS_INVALIDATE +is specified. +.It Bq Er EINVAL +The +.Fa addr +argument +is not a multiple of the hardware page size. +.It Bq Er EINVAL +The +.Fa len +argument +is too large or negative. +.It Bq Er EINVAL +The +.Fa flags +argument +was both MS_ASYNC and MS_INVALIDATE. +Only one of these flags is allowed. +.El +.Sh SEE ALSO +.Xr madvise 2 , +.Xr mincore 2 , +.Xr mlock 2 , +.Xr mprotect 2 , +.Xr munmap 2 +.Sh HISTORY +The +.Fn msync +system call first appeared in +.Bx 4.4 . +.Sh BUGS +The +.Fn msync +system call is obsolete since +.Bx +implements a coherent file system buffer cache. +However, it may be used to associate dirty VM pages with file system +buffers and thus cause them to be flushed to physical media sooner +rather than later. |