From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.xen@gmail.com>
Subject: Re: [PATCH] Avoid panic when adjusting sedf parameters
Date: Thu, 17 Nov 2011 13:52:48 +0000
Message-ID: <CAEAC230.25135%keir.xen@gmail.com>
References: <4EC51A8D0200007800061933@nat28.tlf.novell.com>
Mime-Version: 1.0
Content-Type: text/plain;
	charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <4EC51A8D0200007800061933@nat28.tlf.novell.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Jan Beulich <JBeulich@suse.com>, Juergen Gross <juergen.gross@ts.fujitsu.com>
Cc: xen-devel@lists.xensource.com
List-Id: xen-devel@lists.xenproject.org

On 17/11/2011 13:30, "Jan Beulich" <JBeulich@suse.com> wrote:

> which would now associate the else with the wrong (inner) if. One
> possible solution that comes to mind would be
> 
> #define for_each_domain_in_cpupool(_d,_c) \
>     for_each_domain_in_cpupool (_d) \
>         if ((_d)->cpupool != (_c)) \
>             continue; \
>         else
> 
> but I think I had seen a more clever solution to this problem, but cannot
> remember/locate it right now.

Given the gcc ({}) construction, you could do a double-loop:
 for ( (_d) = rcu_dereference(domain_list);     \
       (_d) != NULL;                            \
       ({ while ((_d) = rcu_dereference((_d)->next_in_list != NULL)
             if ((_d)->cpupool == (_c)) break;
          (_d); }) )

A bit ugly. ;-) And I still worry about cpupool locking...

 -- Keir