Re: [PATCHSET v4] Uncached buffered IO

[Stefan Metzmacher]

Hi Jens,

I'm wondering about the impact on memory mapped files.

Let's say one (or more) process(es) called mmap on a file in order to
use the content of the file as persistent shared memory.
As far as I understand pages from the page cache are used for this.

Now another process uses RWF_UNCACHED for a read of the same file.
What happens if the pages are removed from the page cache?
Or is the removal deferred based on some refcount?

Thanks!
metze