Messages in this thread | | | Subject | Re: [PATCH v2 2/7] iommu: IOMMU Groups | From | Benjamin Herrenschmidt <> | Date | Thu, 21 Jun 2012 10:07:34 +1000 |
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On Wed, 2012-06-20 at 10:48 -0600, Alex Williamson wrote:
> Yes, I was assuming the caller held a reference to the struct device to > prevent such a race, looks like I forgot to document that in the > comments. I'll have to think about if we can fix the ordering problem. > We can re-order the list_add vs notification, but then we just risk > dropping the remove. Perhaps we need to extend the lock or add another > to group {list add, notify add}, {list lookup, remove, notify remove}. > I'm not even sure this race is possible though w/ a device reference.
Or we put the burden on the callers not to racily add & remove, including full completion of related notifiers. Might not even be hard (ie might already be the case).
Cheers, Ben.
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