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28 .\" @(#)msync.2 8.2 (Berkeley) 6/21/94
36 .Nd synchronize a mapped region
42 .Fn msync "void *addr" "size_t len" "int flags"
47 writes any modified pages back to the file system and updates
48 the file modification time.
51 is 0, all modified pages within the region containing
56 is non-zero, only those pages containing
60 succeeding locations will be examined.
63 argument may be specified as follows:
65 .Bl -tag -width ".Dv MS_INVALIDATE" -compact
69 Perform synchronous writes
71 Invalidate all cached data
82 Some or all of the pages in the specified region are locked and
89 is not a multiple of the hardware page size.
94 is too large or negative.
99 was both MS_ASYNC and MS_INVALIDATE.
100 Only one of these flags is allowed.
102 An error occurred while writing at least one of the pages in
103 the specified region.
114 system call first appeared in
119 system call is usually not needed since
121 implements a coherent file system buffer cache.
122 However, it may be used to associate dirty VM pages with file system
123 buffers and thus cause them to be flushed to physical media sooner