Messages in this thread | | | Date | Thu, 16 Jan 2020 10:13:11 -0400 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v5 1/2] mm/mmu_notifier: make interval notifier updates safe |
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On Wed, Jan 15, 2020 at 02:04:47PM -0800, Ralph Campbell wrote:
> But I see your point if this sequence is done outside of the invalidate > callback. In that case, if the driver shrank the interval, an invalidate > callback for the right hand side could be missed before the insertion of > the new interval for the right hand side. > I'll explain this in the comments for nouveau_svmm_do_unmap() and > dmirror_do_unmap().
Yes, this is why I'm not sure this is a good API for the core to expose.
Batch manipulations is a resonable thing, but it should be forced to work under safe conditions, ie while holding the required 'inv_begin' on the interval tree, and the batching APIs should assert this requirement.
Jason
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