gianfar: Optimize struct gfar_priv_tx_q for two cache lines
Resize and regroup structure members to eliminate memory holes and
to pack the structure into 2 cache lines (from 3).
tx_ring_size was resized from 4 to 2 bytes and few members were re-grouped
in order to eliminate byte holes and achieve compactness.
Where possible, few members were grouped according to their usage and access
order (i.e. start_xmit vs. clean_tx_ring members), less important members
were pushed at the end.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/gianfar.h b/drivers/net/ethernet/freescale/gianfar.h
index 91bb2de..045c0d2 100644
--- a/drivers/net/ethernet/freescale/gianfar.h
+++ b/drivers/net/ethernet/freescale/gianfar.h
@@ -935,26 +935,25 @@
* @txtime: coalescing value if based on time
*/
struct gfar_priv_tx_q {
+ /* cacheline 1 */
spinlock_t txlock __attribute__ ((aligned (SMP_CACHE_BYTES)));
- struct sk_buff ** tx_skbuff;
- /* Buffer descriptor pointers */
- dma_addr_t tx_bd_dma_base;
struct txbd8 *tx_bd_base;
struct txbd8 *cur_tx;
- struct txbd8 *dirty_tx;
- struct tx_q_stats stats;
- struct net_device *dev;
- struct gfar_priv_grp *grp;
- u16 skb_curtx;
- u16 skb_dirtytx;
- u16 qindex;
- unsigned int tx_ring_size;
unsigned int num_txbdfree;
+ unsigned short skb_curtx;
+ unsigned short tx_ring_size;
+ struct tx_q_stats stats;
+ struct gfar_priv_grp *grp;
+ /* cacheline 2 */
+ struct net_device *dev;
+ struct sk_buff **tx_skbuff;
+ struct txbd8 *dirty_tx;
+ unsigned short skb_dirtytx;
+ unsigned short qindex;
/* Configuration info for the coalescing features */
- unsigned char txcoalescing;
+ unsigned int txcoalescing;
unsigned long txic;
- unsigned short txcount;
- unsigned short txtime;
+ dma_addr_t tx_bd_dma_base;
};
/*