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] only set scheduler timer for non-idle CPU

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, Thomas Pfeuffer <thomas.pfeuffer@xxxxxxxx>, "Yu, Ke" <ke.yu@xxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] only set scheduler timer for non-idle CPU
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 02 Apr 2009 14:18:41 +0100
Delivery-date: Thu, 02 Apr 2009 06:19:08 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C5FA76E3.5880%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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcmzkXHgTPa/n0P0RNGJeQlT9mWitQAAmMDUAABtYNo=
Thread-topic: [Xen-devel] [PATCH] only set scheduler timer for non-idle CPU
User-agent: Microsoft-Entourage/
On 02/04/2009 14:06, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

>> I think your patch is not good in case sedf-scheduler is used. If idle VCPU
>> is the current "running" VCPU, the scheduler timer is set to the next "period
>> begin" of the first VCPU in the wait queue.
>> Your patch prevents sedf from taking the VCPUs waiting for their next period
>> into the runnable queue again.
> It¹s probably cleaner always to respect the specific scheduler¹s scheduling
> quantum in schedule.c, but then have sched_credit.c return a very large
> quantum (large as possible) for the idle VCPU.

I checked in something to this effect as c/s 19500.

 -- Keir

Xen-devel mailing list