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] [PATCH 1/9] Add cpu idle pwr mgmt to xen

To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>, "Jan Beulich" <jbeulich@xxxxxxxxxx>, "Wei, Gang" <gang.wei@xxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH 1/9] Add cpu idle pwr mgmt to xen
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Wed, 30 Apr 2008 17:12:31 +0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 30 Apr 2008 02:13:02 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C43DF247.20177%keir.fraser@xxxxxxxxxxxxx>
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: <48183A3F.76E4.0078.0@xxxxxxxxxx> <C43DF247.20177%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Aciqn8RNAuw9vxaTEd2yrAAX8io7RQAAWadw
Thread-topic: [Xen-devel] [PATCH 1/9] Add cpu idle pwr mgmt to xen
One thing kicking me just now is, whether Linux address check
style can be used here by temporarily increasing address limit
in compat logic to bypass relative check in common code? I
didn't see obvious benefit to reserve a guest virtual addr range
and let each component to manage internal allocation themselves.
Linux style seems simpler and compat logic can just use xmalloc
to create native copy to reduce xlat complexity.


>From: Keir Fraser
>Sent: 2008年4月30日 16:54
>On 30/4/08 08:22, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:
>>>>> "Wei, Gang" <gang.wei@xxxxxxxxx> 30.04.08 05:27 >>>
>>> Revising done according to Jan's comments. Resend.
>> Thanks. Unfortunately you now use a static (but not per-CPU) 
>variable -
>> while I understand that it is expected that the call is done 
>just once, I
>> don't think this is a good thing to do.
>Why is the variable even non-local? Is it just to make the 
>interfaces simpler? It's a false simplification if so, and I 
>think you'd be
>better making the variable an explicit parameter to those functions.
>Also I agree with Jan regarding non-ISO C usage of loop-header variable
>declarations (don't do it) and also you should check copy_from_guest*()
>return values and return -EFAULT where appropriate. His 
>comment regarding
>explicit padding or use of uint32_t in your public bitfield 
>also sounds good
>to me.

Xen-devel mailing list