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From: Keir Fraser <keir.xen@gmail.com>
To: Jan Beulich <JBeulich@suse.com>,
	Juergen Gross <juergen.gross@ts.fujitsu.com>
Cc: xen-devel@lists.xensource.com
Subject: Re: [PATCH] Avoid panic when adjusting sedf parameters
Date: Thu, 17 Nov 2011 13:48:36 +0000	[thread overview]
Message-ID: <CAEAC134.25132%keir.xen@gmail.com> (raw)
In-Reply-To: <4EC51A8D0200007800061933@nat28.tlf.novell.com>

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

  reply	other threads:[~2011-11-17 13:48 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-17 13:03 [PATCH] Avoid panic when adjusting sedf parameters Juergen Gross
2011-11-17 13:30 ` Jan Beulich
2011-11-17 13:48   ` Keir Fraser [this message]
2011-11-17 14:02     ` Juergen Gross
2011-11-17 13:52   ` Keir Fraser
2011-11-17 14:04     ` Juergen Gross
2011-11-17 14:32       ` Jan Beulich
2011-11-17 14:41         ` Juergen Gross
2011-11-17 14:29     ` Jan Beulich
  -- strict thread matches above, loose matches on Subject: below --
2011-11-17 14:37 Juergen Gross
2011-11-17 12:33 Juergen Gross
2011-11-17 12:43 ` George Dunlap
2011-11-17 13:07   ` Juergen Gross

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