On Wed, Aug 28, 2013 at 05:33:49PM +0800, Xiao Guangrong wrote:
> > Or what if desc is moved to another rmap, but then it
> > is moved back to initial rmap (but another place in the desc list) so
> > the check here will not catch that we need to restart walking?
>
> It is okay. We always add the new desc to the head, then we will walk
> all the entires under this case.
>
Which races another question: What if desc is added in front of the list
behind the point where lockless walker currently is?
> Right?
Not sure. While lockless walker works on a desc rmap can be completely
destroyed and recreated again. It can be any order.
--
Gleb.
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