Re: [QUICKLIST 3/4] Quicklist support for x86_64

Christoph Lameter
2007-04-09T18:56:39Z

On Mon, 9 Apr 2007, Andi Kleen wrote:

> > Otherwise you will leak pages to the page allocator before the tlb flush
> > occurred.
>
> I don't get it sorry. Can you please explain in more detail?

On process teardown pages are freed via the tlb mechanism. That mechanism
guarantees that TLBs for pages are flushed before they can be reused. We
tie into that and put pages on quicklists. The quicklists are trimmed
after the TLB flush.

If a shrinker would indepedently free pages from the quicklists then this
mechanism would no longer work and pages that still have a valid TLB for
one process may be reused by other processes.