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 13:48:36 +0000
Message-ID: <CAEAC134.25132%keir.xen@gmail.com>
References: <4EC51A8D0200007800061933@nat28.tlf.novell.com>
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To: Jan Beulich <JBeulich@suse.com>, Juergen Gross <juergen.gross@ts.fujitsu.com>
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On 17/11/2011 13:30, "Jan Beulich" <JBeulich@suse.com> wrote:

>> +#define for_each_domain_in_cpupool(_d,_c)       \
>> + for ( (_d) = rcu_dereference(domain_list);     \
>> +       (_d) != NULL;                            \
>> +       (_d) = rcu_dereference((_d)->next_in_list )) \
> 
> Wouldn't this, up to here, simply be for_each_domain()?
> 
>> +       if ((_d)->cpupool == (_c))
> 
> This is dangerous - consider code like

I also wonder (and this is true for the existing open-coded versions too)
whether we have sufficient locking around use of d->cpupool? Do these loops
hold enough locks to ensure that d->cpupool doesn't change under their feet?

 -- Keir