Re: VM subsystem bug in 2.4.0 ?

Stephen C. Tweedie
2001-01-09T14:12:16Z

Hi,

On Mon, Jan 08, 2001 at 04:30:10PM -0200, Rik van Riel wrote:
> On Mon, 8 Jan 2001, Linus Torvalds wrote:
> >
> > The only solution I see is something like a "active_immobile"
> > list, and add entries to that list whenever "writepage()"
> > returns 1 - instead of just moving them to the active list.
>
> Just marking them with a special "do not deactivate me"
> bit seems to work fine enough. When this special bit is
> set, we simply move the page to the back of the active
> list instead of deactivating.

But again, how do you clear the bit? Locking is a per-vma property,
not per-page. I can mmap a file twice and mlock just one of the
mappings. If you get a munlock(), how are you to know how many other
locked mappings still exist?

--Stephen