Re: MLX4 Cq Question

[Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 18/05/2013 00:37, Roland Dreier wrote:
> you see that when freeing a CQ, we first do the HW2SW_CQ firmware
> command; once this command completes, no more events will be generated
> for that CQ.  Then we do synchronize_irq for the CQ's interrupt
> vector.  Once that completes, no more completion handlers will be
> running for the CQ, so we can safely delete the CQ from the radix tree
> (relying on the radix tree's safety of deleting one entry while
> possibly looking up other entries, so no lock is needed).  We also use
> the lock to synchronize against the CQ event function, which as you
> noted does take the lock too.
>
> Basic idea is that we're tricky and careful so we can make the fast
> path (completion interrupt handling) lock-free, but then use locks and
> whatever else needed in the slow path (CQ async event handling, CQ
> destroy).

Jack, so do we finally agree to this analysis?  last time when this was 
on the list, I was under the impression that there was no consensus and 
I also see that on the stack we provide to customers there's a patch of 
yours in that area, or it may fix another bug?

Or.
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