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

[Xen-devel] Re: credit scheduler

To: David Xu <davidxu06@xxxxxxxxx>
Subject: [Xen-devel] Re: credit scheduler
From: George Dunlap <george.dunlap@xxxxxxxxxx>
Date: Tue, 21 Jun 2011 15:04:33 +0100
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Tue, 21 Jun 2011 07:07:16 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <BANLkTi=KM6JEg2_Wze6XgTm10oLn_cajrw@xxxxxxxxxxxxxx>
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: <BANLkTi=KM6JEg2_Wze6XgTm10oLn_cajrw@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Fri, 2011-06-17 at 15:48 +0100, David Xu wrote:
> Hi,
> 
> 
> What's the meaning of runq_sort in csched_privates and runq_sort_last
> in csched_pcpu? Thanks.

The hint can be found in this comment (xen/common/sched_credit.c:1140):

    /* Inform each CPU that its runq needs to be sorted */
    prv->runq_sort++;

Every 30ms, the "master" cpu will increment prv->runq_sort.

Every 10ms, each individual cpu will check prv->runq_sort, to see if it
has been incremented (by comparing it to runq_sort_last).  If it has
incermented, then the cpu will sort its runqueue by priority.

 -George




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

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