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From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v2 net-next 06/12] qed: Add LL2 slowpath handling
Date: Thu, 05 Oct 2017 17:20:13 -0700 (PDT)
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From: "Kalderon, Michal" <Michal.Kalderon@cavium.com>
Date: Thu, 5 Oct 2017 20:27:22 +0000

> The spinlock is required for the case that rx buffers are posted
> from a different thread, where it could be run simultaneously to the
> rxq_completion.

This only brings us back to my original argument, if the lock is
necessary in order to synchronize with those paths, how can you
possible drop the lock safely here?

Is it because you re-read the head and tail pointers of the queue each
time around the loop?