Re: [RFC 0/3] Recursive reclaim (on __PF_MEMALLOC)

Christoph Lameter
2007-08-16T20:27:34Z

On Thu, 16 Aug 2007, Nick Piggin wrote:

> > Honestly, I don't. They very much do not solve the problem, they just
> > displace it.
>
> Well perhaps it doesn't work for networked swap, because dirty accounting
> doesn't work the same way with anonymous memory... but for _filesystems_,
> right?

Regular reclaim also cannot immediately write out pages. Writes are
usually deferred. If you have too many anonymous pages in regular reclaim
then you can have the same issues.

The difference is that recursive reclaim does not trigger writeout at
the moment but we could address that by having a pageout list that then
starts writes from another context. Then both reclaims would be able to
trigger writeout.