Re: [Xen-devel] [PATCH 2/2] balloon driver: don't use apply_to_page_range for xenLinux/ia64 - Isaku Yamahata - com.xensource.lists.xen-ia64-devel

5 messages in com.xensource.lists.xen-ia64-develRe: [Xen-devel] [PATCH 2/2] balloon d...

From	Sent On	Attachments
Isaku Yamahata	27 Apr 2006 23:32	.patch
Keir Fraser	28 Apr 2006 00:00
Isaku Yamahata	28 Apr 2006 02:14
Keir Fraser	28 Apr 2006 06:56
Isaku Yamahata	28 Apr 2006 21:36	.patch

Subject:	Re: [Xen-devel] [PATCH 2/2] balloon driver: don't use apply_to_page_range for xenLinux/ia64
From:	Isaku Yamahata (yama...@valinux.co.jp)
Date:	04/28/2006 02:14:28 AM
List:	com.xensource.lists.xen-ia64-devel

On Fri, Apr 28, 2006 at 08:00:30AM +0100, Keir Fraser wrote:

The existing code should work on ia64, right? It's not performance critical code.

Unfortunately no. Roughly init_mm is only used to map vmalloc area on Linux/ia64. init_mm of Linux/ia64 doesn't map the area of [PAGE_OFFSET, ...]. Traversing init_mm with a virtual address of the area gives a zero-filled pte entry. It also populates unnecessary pud/pmd/pte pages.

Linux/ia64 resolves faults on the area [PAGE_OFFSET, ...] by tlb insert without init_mm traverse after checking faulted virtual address and its privilege.