Re: [PATCH 01 of 16] remove nr_scan_inactive/active

Andrew Morton
2007-06-28T23:13:50Z

On Thu, 28 Jun 2007 19:04:05 -0400
Rik van Riel <riel@redhat.com> wrote:

> > Sigh. We had a workload (forget which, still unfixed) in which things
> > would basically melt down in that linear anon_vma walk, walking 10,000 or
> > more vma's. I wonder if that's what's happening here?
>
> That would be a large multi-threaded application that fills up
> memory. Customers are reproducing this with JVMs on some very
> large systems.

So.... does that mean "yes, it's scanning a lot of vmas"?

If so, I expect there will still be failure modes, whatever we do outside
of this. A locked, linear walk of a list whose length is
application-controlled is going to be a problem. Could be that we'll need
an O(n) -> O(log(n)) conversion, which will be tricky in there.