[E1000-devel] [RFC][PATCH] ixgbe: fix tx queue index

[Wu F. <fen...@in...>]

Don't do the num_tx_queues based masking on calculating tx queue index.

1) num_tx_queues is not always power-of-2, because it also depends on
   the online cpu numbers. So the masking could be a performance bug
   on a 6 cpu system.
2) queue_mapping will be limited by real_num_tx_queues=num_tx_queues
   in the generic netdev function set_cur_queue_map(). So the bound
   limiting here is not necessary.

Signed-off-by: Wu Fengguang <fen...@in...>
---
 drivers/net/ixgbe/ixgbe_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- mm.orig/drivers/net/ixgbe/ixgbe_main.c
+++ mm/drivers/net/ixgbe/ixgbe_main.c
@@ -4223,7 +4223,7 @@ static int ixgbe_xmit_frame(struct sk_bu
 	int count = 0;
 	unsigned int f;
 
-	r_idx = (adapter->num_tx_queues - 1) & skb->queue_mapping;
+	r_idx = skb->queue_mapping;
 	tx_ring = &adapter->tx_ring[r_idx];
 
 	if (adapter->vlgrp && vlan_tx_tag_present(skb)) {