On 09/01/2014 11:47 PM, David Miller wrote:

If there were no more packets coming, this is wasted useless polling
time in atomic context.

turns out that this gives a 20-30% perf improvement for tests like
iperf.

when there are no more packets coming, the extra 12 microsecond
delay is not that big of a deal anyway. The point was that the extra
12 micro-second tax in the quiescent network state is less expensive
than exiting interrupt context, taking another interrupt and doing
another ldc_read, when there is actually a burst of packets.

notice that there are many other such udelay() loops elsewhere in
the code.

I can remove the retries and submit patch 1/1 again later today.

Everything should be event based, and we should not be compensating
and making sacrifices for a producer slower than we are as a consumer.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html