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

Re: [Xen-devel] Re: [RFC PATCH V4 2/5] cpuidle: list based cpuidle drive

To: Len Brown <lenb@xxxxxxxxxx>
Subject: Re: [Xen-devel] Re: [RFC PATCH V4 2/5] cpuidle: list based cpuidle driver registration and selection
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Fri, 25 Mar 2011 11:35:24 -0400
Cc: venki@xxxxxxxxxx, ak@xxxxxxxxxxxxxxx, suresh.b.siddha@xxxxxxxxx, sfr@xxxxxxxxxxxxxxxx, peterz@xxxxxxxxxxxxx, benh@xxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxx, arjan@xxxxxxxxxxxxxxx, Trinabh Gupta <trinabh@xxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 25 Mar 2011 08:37:11 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <alpine.LFD.2.02.1103250245570.32565@x980>
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: <20110322123208.28725.30945.stgit@xxxxxxxxxxxxxxxxxxx> <20110322123233.28725.92874.stgit@xxxxxxxxxxxxxxxxxxx> <alpine.LFD.2.02.1103222254420.10549@x980> <4D89BBDD.5090505@xxxxxxxxxxxxxxxxxx> <alpine.LFD.2.02.1103231633030.12911@x980> <4D8B5197.2060306@xxxxxxxxxxxxxxxxxx> <alpine.LFD.2.02.1103250245570.32565@x980>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.20 (2009-06-14)
On Fri, Mar 25, 2011 at 03:05:36AM -0400, Len Brown wrote:
> > I think there are other problems too, related to saving and restoring
> > of pm_idle pointer. For example, cpuidle itself saves current value
> > of pm_idle, flips it and then restores the saved value. There is
> > no guarantee that the saved function still exists. APM does exact
> > same thing (though it may not be used these days).
> > 
> > The problem also is that a number of architectures have copied the
> > same design based on pm_idle; so its spreading.
> 
> pm_idle is a primitive design yes, but I think the issue
> with pm_idle is a theoretical one, at least on x86;
> as there isn't any other code scribbling on pm_idle
> in practice.  So this is clean-up, rather than bug-fix work...
> 
> > > It isn't immediately clear to me that all of these options
> > > need to be preserved.
> > 
> > So what do you suggest can be removed?
> 
> I sent a series of small patches yesterday to get the ball rolling...
> https://lkml.org/lkml/2011/3/24/54
> 
> I think the xen thing can go away.

The xen thing being the setting of cpuidle to halt or the proposed
patch?

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