Re: [rfc] lockless pagecache

Andrew Morton
2005-06-27T08:16:13Z

Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> Also, the memory usage regression cases that fault ahead brings makes it
> a bit contentious.

faultahead consumes no more memory: if the page is present then point a pte
at it. It'll make reclaim work a bit harder in some situations.

> I like that the lockless patch completely removes the problem at its
> source and even makes the serial path lighter. The other things is, the
> speculative get_page may be useful for more code than just pagecache
> lookups. But it is fairly tricky I'll give you that.

Yes, it's scary-looking stuff.

> Anyway it is obviously not something that can go in tomorrow. At the
> very least the PageReserved patches need to go in first, and even they
> will need a lot of testing out of tree.
>
> Perhaps it can be discussed at KS and we can think about what to do with
> it after that - that kind of time frame. No rush.
>
> Oh yeah, and obviously it would be nice if it provided real improvements
> on real workloads too ;)

umm, yes.