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/
Home Products Support Community News


Re: [Xen-devel] x86-64/kexec: crashkernel= without @xM suffix

To: Jan Beulich <JBeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] x86-64/kexec: crashkernel= without @xM suffix
From: Simon Horman <horms@xxxxxxxxxxxx>
Date: Sun, 2 May 2010 12:21:41 +1000
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Sat, 01 May 2010 19:22:39 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4BDA97DE0200007800000C43@xxxxxxxxxxxxxxxxxx>
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <4BDA97DE0200007800000C43@xxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.20 (2009-06-14)
On Fri, Apr 30, 2010 at 07:42:06AM +0100, Jan Beulich wrote:
> Was this ever tested by anyone? Has it ever worked with any Linux
> as secondary kernel? We're getting reports (and analysis confirms
> this) that the fact that Xen places the hole at the highest suitable
> address below 4G prevents kexec from working.
> A possible fix is non-obvious, since there doesn't appear to be a
> hard boundary below which the hole must reside (especially for a
> 32-bit secondary kernel; for a 64-bit one it seems like any place
> below 2G would be acceptable).
> Simply using Linux' strategy and allocating at the lowest possible
> address doesn't seem too nice a solution either, as we try to
> conserve on the use of low memory as much as possible almost
> everywhere else.

Hi Jan,

I don't recall specifically testing this combination.
I think that your suggestion of simply locating the hole as
low as possible is a good one though I fear there is
a gotcha in there somewhere.

Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • Re: [Xen-devel] x86-64/kexec: crashkernel= without @xM suffix, Simon Horman <=