sfc: last resort fallback for lack of xdp tx queues
Previous patch addressed the situation of having some free resources for xdp tx but not enough for one tx queue per CPU. This patch address the worst case of not having resources at all for xdp tx. Instead of using queues dedicated to xdp, normal queues used by network stack are shared for both cases, using __netif_tx_lock for synchronization. Also queue stop/restart must be considered in the xdp path to avoid freezing the queue. This is not the ideal situation we might want to be, and a performance penalty is expected both for normal and xdp traffic, but at least XDP will work in all possible situations (with a warning in the logs), improving a bit the pain of not knowing in what situations we can use it and in what situations we cannot. Signed-off-by:Íñigo Huguet <ihuguet@redhat.com> Signed-off-by:
David S. Miller <davem@davemloft.net>
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