ixgbe: Re-adjust ring layouts to have better cacheline efficiency

This patch rearranges the ixgbe_ring struct to make better use of
cacheline efficiency.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe.h

@@ -121,19 +121,18 @@ struct ixgbe_queue_stats {
 
 struct ixgbe_ring {
 	void *desc;			/* descriptor ring memory */
-	dma_addr_t dma;			/* phys. address of descriptor ring */
-	unsigned int size;		/* length in bytes */
-	unsigned int count;		/* amount of descriptors */
-	unsigned int next_to_use;
-	unsigned int next_to_clean;
-	u8 atr_sample_rate;
-	u8 atr_count;
-
-	int queue_index; /* needed for multiqueue queue management */
 	union {
 		struct ixgbe_tx_buffer *tx_buffer_info;
 		struct ixgbe_rx_buffer *rx_buffer_info;
 	};
+	u8 atr_sample_rate;
+	u8 atr_count;
+	u16 count;			/* amount of descriptors */
+	u16 rx_buf_len;
+	u16 next_to_use;
+	u16 next_to_clean;
+
+	u8 queue_index; /* needed for multiqueue queue management */
 
 	u16 head;
 	u16 tail;
@@ -141,20 +140,24 @@ struct ixgbe_ring {
 	unsigned int total_bytes;
 	unsigned int total_packets;
 
-	u16 reg_idx; /* holds the special value that gets the hardware register
-		      * offset associated with this ring, which is different
-		      * for DCB and RSS modes */
-
 #ifdef CONFIG_IXGBE_DCA
 	/* cpu for tx queue */
 	int cpu;
 #endif
+
+	u16 work_limit;			/* max work per interrupt */
+	u16 reg_idx;			/* holds the special value that gets
+					 * the hardware register offset
+					 * associated with this ring, which is
+					 * different for DCB and RSS modes
+					 */
+
 	struct ixgbe_queue_stats stats;
 	unsigned long reinit_state;
+	u64 rsc_count;			/* stat for coalesced packets */
 
-	u16 work_limit;                /* max work per interrupt */
-	u16 rx_buf_len;
-	u64 rsc_count;                 /* stat for coalesced packets */
+	unsigned int size;		/* length in bytes */
+	dma_addr_t dma;			/* phys. address of descriptor ring */
 };
 
 enum ixgbe_ring_f_enum {