WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] [PATCH] linux/x86: Initialize high_memory as early as po

To: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] linux/x86: Initialize high_memory as early as possible
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Thu, 29 Jun 2006 15:47:19 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 29 Jun 2006 07:47:41 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <44A3F9DA.76E4.0078.0@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <44A3F4DB.76E4.0078.0@xxxxxxxxxx> <f365d75b5ad7e76dc29e078ca9bbb778@xxxxxxxxxxxx> <44A3F9DA.76E4.0078.0@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

On 29 Jun 2006, at 15:03, Jan Beulich wrote:

This didn't seem safe enough to me, and apparently also not to the original
author (at least I attribute the FIXME comment to this) - after all not
everything before FIXADDR_START is high memory.
One could say that under DEBUG_HIGHMEM the check should be more strict
(so that the subsequent BUG() condition fires in more broken cases), but
without DEBUG_HIGHMEM it might be left as-is to avoid zapping incorrect
page table entries.

Any kmap_atomic virtual address should be above FIXADDR_START. You have a point about debugging though (e.g., passing a non-atomic kmap address to kunmap_atomic).

 -- Keir


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>