> > > This still does not address the situation where a file is 'permanently'
You're right. In theory, at least. But in practice I don't think
this matters. Show me an application that writes to a shared mapping
then doesn't call either msync or munmap and doesn't even exit.
If there were lot of these apps, then this bug would have been fixed
lots of years earlier. In fact there are _very_ few apps writing to
shared mappings at all.
Applications should be encouraged to call msync(MS_ASYNC) because:
- it's very fast (basically a no-op) on recent linux kernels
- it's the only portable way to guarantee, that the data you written
will _ever_ hit the disk.
There's really no downside to using msync(MS_ASYNC) in your
application, so making an effort to support applications that don't do
this is stupid, IMO.