Messages in this thread | | | Date | Fri, 25 Jun 2021 09:48:12 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH v5 for-next 3/3] IB/core: Obtain subnet_prefix from cache in IB devices |
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On Fri, Jun 25, 2021 at 11:33:58AM +0530, Anand Khoje wrote: > > If the above change is to be made, there could arise a scenario in which: > In case of a cache_update event, another application/module could try to > call ib_query_port() and read subnet_prefix while the cache is still getting > updated and the application/module could end up reading a stale value of > subnet_prefix.
Applications relying on this data must hook the event and update their state when the event fires.
So long as ib_query_port returns the correct value in the event handler it is all OK. This whole thing is racy - the HW can change the subnet_prefix at anytime, this is just shuffling the race around.
> - Is it possible that different GIDs in the gid_table will have different > values of subnet_prefix?
Valid GIDs should have the same prefix
Jason
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