[Xen-devel] RE: [PATCH] CPUIDLE: revise tsc-save/restore to avoi

To:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject:	[Xen-devel] RE: [PATCH] CPUIDLE: revise tsc-save/restore to avoid big tsc skew between cpus
From:	"Wei, Gang" <gang.wei@xxxxxxxxx>
Date:	Sat, 6 Dec 2008 15:36:35 +0800
Accept-language:	en-US
Acceptlanguage:	en-US
Cc:	"Tian, Kevin" <kevin.tian@xxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date:	Fri, 05 Dec 2008 23:37:07 -0800
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to:	<C55EEF8D.9EB%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/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:	<C55ED7B9.9C5%keir.fraser@xxxxxxxxxxxxx> <C55EEF8D.9EB%keir.fraser@xxxxxxxxxxxxx>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index:	AclWoeM2xc+X6mj6QOaQHsyxDmpzagAFRoNpAACb7OAABH8KUAADs+LEAAOM+XwAIvWIwA==
Thread-topic:	[PATCH] CPUIDLE: revise tsc-save/restore to avoid big tsc skew between cpus

On Friday, December 05, 2008 10:48 PM, Keir Fraser wrote:
> On 05/12/2008 13:06, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:
> 
>>> Below patch should be what you expected. It will still bring continuously
>>> increasing tsc skew. If I pin all domains' vcpus on 1 pcpu, the skew is
>>> increasing faster.
>> 
>> I applied a modified version of this as c/s 18873. Primarily I removed
>> scale_time() and replaced with a simpler reciprocal function which is applied
>> to scale factors to invert them. Please take a look.
> 
> I should have tested the reciprocal function before checkin. A fixed (and
> now rather less simple) version is in c/s 18875.

Your fix is absolutely right. Now we at least make the tsc skew increasing in a 
far slower speed. Thanks, and I will consider how to make my original patch 
work for constant_tsc case only.

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

<Prev in Thread]

Current Thread

[Next in Thread>

Previous by Date:

Re: [Xen-devel] ADs over dom0 iSCSI = high page_count(), Keir Fraser

Next by Date:

[Xen-devel] about Xen API's 'api' attribute, Yanjun Wu

Previous by Thread:

[Xen-devel] Re: [PATCH] CPUIDLE: revise tsc-save/restore to avoid big tsc skew between cpus, Keir Fraser

Next by Thread:

[Xen-devel] Reuse QEMU image for HVM?, Jun Koi

Indexes:

[Date] [Thread] [Top] [All Lists]

WARNING - OLD ARCHIVES

xen-devel

[Xen-devel] RE: [PATCH] CPUIDLE: revise tsc-save/restore to avoid big ts