Re: Page cache and swapping

Bernd Schmidt (crux@Pool.Informatik.RWTH-Aachen.DE)
Fri, 27 Jun 1997 13:30:21 +0200 (MET DST)

> I'm very grateful for all comments about problems with freeing shared
> memory. I have still no answer to the question about removing the
> page cache page from processes page table, if page->count=1.
> Does it mean that informations in mm.h are wrong and page->count=1
> for pages, which do not belong to any process and are still in the
> page cache (the swapping mechanism sets the present bit in the page table
> to zero and the page still remains in memory)?

When page->count == 1 for a page cache page, this means that it is not in
any process page table. The count is incremented once just for recording that
the page is in the page cache.