Re: [Qemu-devel] [PULL 27/28] migration: protect migration_bitmap

[Wen Congyang]

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