Messages in this thread | | | Date | Mon, 15 Oct 2012 23:10:09 -0700 (PDT) | From | David Rientjes <> | Subject | Re: mpol_to_str revisited. |
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On Tue, 16 Oct 2012, KOSAKI Motohiro wrote:
> >> I don't think 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a is right fix. > > > > It's certainly not a complete fix, but I think it's a much better result > > of the race, i.e. we don't panic anymore, we simply fail the read() > > instead. > > Even though 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a itself is simple. It bring > to caller complex. That's not good and have no worth. >
Before: the kernel panics, all workloads cease. After: the file shows garbage, all workloads continue.
This is better, in my opinion, but at best it's only a judgment call and has no effect on anything.
I agree it would be better to respect the return value of mpol_to_str() since there are other possible error conditions other than a freed mempolicy, but let's not consider reverting 80de7c3138. It is obviously not a full solution to the problem, though, and we need to serialize with task_lock().
Dave, are you interested in coming up with a patch?
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