Re: [RFC] 0/4 Migration Cache Overview

Christoph Lameter
2006-02-21T18:04:05Z

On Tue, 21 Feb 2006, Marcelo Tosatti wrote:

> The idea was to create a "partition" inside the swapcache which allows
> for mapping+offset->pfn translation _without_ actually occupying space
> in the swap map (an idr table is used instead).
>
> But apparently Christoph's mechanism adds the PFN number into
> the page table entry itself, thus fulfilling the requirement for
> "mapping+offset"->pfn indexing required for removal of pages underneath
> a living process. Is that right?

Right. Swap ptes contain the index into swap space which I am using to
preserve the information contained in the pte's of anonymous pages. Thus
the existing swap ptes couild be used. There were just a few minor
modifications to the swap functions required.