|MSYNC(2)||System Calls Manual||MSYNC(2)|
synchronize a mapped region
Standard C Library (libc, -lc)
*addr, size_t len,
system call writes any modified pages back to the file system and updates
the file modification time. If len is 0, all modified
pages within the region containing addr will be
flushed; if len is non-zero, only those pages
containing addr and len-1
succeeding locations will be examined. The flags
argument may be specified as follows:
msync() function returns the
value 0 if successful; otherwise the value -1 is returned and
the global variable errno is set to indicate the
msync() system call will fail if:
- Some or all of the pages in the specified region are locked and
- The addr argument is not a multiple of the hardware page size.
- The addresses in the range starting at addr and continuing for len bytes are outside the range allowed for the address space of a process or specify one or more pages that are not mapped.
- The flags argument was both MS_ASYNC and MS_INVALIDATE. Only one of these flags is allowed.
- An error occurred while writing at least one of the pages in the specified region.
msync() system call first appeared in
msync() system call is usually not
needed since BSD 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.
|March 18, 2012||Debian|