ixgbe: Make queue pairs on single MSI-X interrupts

This patch pairs similar-numbered Rx and Tx queues onto a single
MSI-X vector.  For example, Tx queue 0 and Rx queue 0's interrupt
with be ethX-RxTx-0.  This allows for more efficient cleanup, since
fewer interrupts will be firing during device operation.  It also
helps with a cleaner CPU affinity for IRQ affinity.
Signed-off-by: NPeter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -3626,10 +3626,10 @@ static int ixgbe_set_interrupt_capability(struct ixgbe_adapter *adapter)
 	 * It's easy to be greedy for MSI-X vectors, but it really
 	 * doesn't do us much good if we have a lot more vectors
 	 * than CPU's.  So let's be conservative and only ask for
-	 * (roughly) twice the number of vectors as there are CPU's.
+	 * (roughly) the same number of vectors as there are CPU's.
 	 */
 	v_budget = min(adapter->num_rx_queues + adapter->num_tx_queues,
-	               (int)(num_online_cpus() * 2)) + NON_Q_VECTORS;
+	               (int)num_online_cpus()) + NON_Q_VECTORS;
 
 	/*
 	 * At the same time, hardware can only support a maximum of