Re: [PATCH] [0/16] POISON: Intro

Andi Kleen
2009-04-09T07:20:27Z

On Wed, Apr 08, 2009 at 10:29:34AM -0700, Roland Dreier wrote:
> > [1] I didn't consider that one high priority since production
> > systems with long uptime shouldn't have much free memory.
>
> Surely there are windows after a big job exits where lots of memory
> might be free. Not sure how big those windows are in practice but it
> does seem if a process using 128GB exits then it might take a while
> before that memory all gets used again.

Yes, it's definitely something to be fixed at some point.
Basically just needs a new entry point into the page_alloc
buddy allocator to unfree a page. The more tricky part
is actually finding a good injector design for testing for it,
there's no natural race free way to get a free page.

-Andi
--
ak@linux.intel.com -- Speaking for myself only.