loft.net> 1229668061 -0800

NIU: Implement discard counters, optimize

Optimize the lightly loaded case, by only synchronizing discards stats
when qlen > 10 indicate potential for drops.

Notice Robert Olsson might disagree with this patch.

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
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