olafbuddenha...@gmx.net wrote: > Hi, > > I'm trying to understand why filesystem servers need proxy memory > objects for io_map(). Unfortunately, I don't have time to read all the > relevant code right now... After a quick glance, my guess is that the > proxy objects are used so the same pager can be provided to several > clients mapping the same file, but with different permissions?
Yes. The underlying limitation is that double-paging is evil. > But if several clients share a pager, doesn't that mean there is no way > to shut down an individual client's mapping when the client closes the > file? Closing a file does not remove the mappings. From glibc manual on mmap: "A new reference for the file specified by FILEDES is created, which is not removed by closing the file. Thanks, Marcus
