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Date: Thu, 09 Jul 2015 21:31:05 +0800
From: Wen Congyang <ghostwcy@gmail.com>
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Subject: Re: [Qemu-devel] [PULL 27/28] migration: protect migration_bitmap
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To: Paolo Bonzini <pbonzini@redhat.com>, Wen Congyang <wency@cn.fujitsu.com>, Kevin Wolf <kwolf@redhat.com>, Juan Quintela <quintela@redhat.com>
Cc: amit.shah@redhat.com, qemu-devel@nongnu.org, Li Zhijian <lizhijian@cn.fujitsu.com>

At 2015/7/9 20:51, Paolo Bonzini Wrote:
>
>
> On 09/07/2015 10:14, Wen Congyang wrote:
>>>       flush_compressed_data(f);
>>>       ram_control_after_iterate(f, RAM_CONTROL_FINISH);
>>> -    migration_end();
>>> -
>>>       rcu_read_unlock();
>>> +
>>> +    migration_end();
>>>       qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
>>
>> Yes, this patch can work. But if the caller hold the rcu read lock in
>> the future, we may need to fix it again. I think it is better to use
>> call_rcu().
>
> Why?  Just document that migration_end must be called outside an RCU
> read-side critical section.  It's not a heavy limitation.
>

If so, it is OK

Thanks
Wen Congyang

> Paolo
>
>