Re: [patch 1/8] Page host virtual assist: unused / free pages.

Nick Piggin
2006-04-25T12:20:22Z

Himanshu Raj wrote:
> [patch 1/8] Page host virtual assist: unused / free pages.
>
> A very simple but already quite effective improvement in the handling
> of guest memory vs. host memory is to tell the host when pages are
> free. That allows the host to avoid the paging of guest pages without
> meaningful content. The host can "forget" the page content and provide
> a fresh frame containing zeroes instead.
>
> To communicate the two page states "unused" and "stable" to the host
> two architecture defined primitives page_hva_set_unused() and
> page_hva_set_stable() are introduced, which are used in the page
> allocator.
>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

This seems reasonable to me. But again, there is no reason for the
mm to know about this "hva" thing.

We already have arch_free_page. Can't you introduce an arch_alloc_page
and use those?

--
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com