Re: [PATCH, RFC] RCU : OOM avoidance and lower latency

Eric Dumazet
2006-01-06T13:10:16Z

Andi Kleen a écrit :
> On Friday 06 January 2006 11:17, Eric Dumazet wrote:
>
>> I assume that if a CPU queued 10.000 items in its RCU queue, then the
>> oldest entry cannot still be in use by another CPU. This might sounds as a
>> violation of RCU rules, (I'm not an RCU expert) but seems quite reasonable.
>
> I don't think it's a good assumption. Another CPU might be stuck in a long
> running interrupt, and still have a reference in the code running below
> the interrupt handler.
>
> And in general letting correctness depend on magic numbers like this is
> very nasty.
>

I agree Andi, I posted a 2nd version of the patch with no more assumptions.

Eric