Keep tx and rx elements separate on different cachelines to prevent
bouncing.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
---
drivers/net/xen-netfront.c | 37 ++++++++++++++++++-------------------
1 file changed, 18 insertions(+), 19 deletions(-)
===================================================================
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -72,22 +72,12 @@ struct netfront_info {
struct list_head list;
struct net_device *netdev;
+ unsigned int evtchn;
+ struct xenbus_device *xbdev;
+
+ spinlock_t tx_lock;
struct xen_netif_tx_front_ring tx;
- struct xen_netif_rx_front_ring rx;
-
- spinlock_t tx_lock;
- spinlock_t rx_lock;
-
- unsigned int evtchn;
-
- /* Receive-ring batched refills. */
-#define RX_MIN_TARGET 8
-#define RX_DFL_MIN_TARGET 64
-#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
- unsigned rx_min_target, rx_max_target, rx_target;
- struct sk_buff_head rx_batch;
-
- struct timer_list rx_refill_timer;
+ int tx_ring_ref;
/*
* {tx,rx}_skbs store outstanding skbuffs. Free tx_skb entries
@@ -106,13 +96,22 @@ struct netfront_info {
grant_ref_t grant_tx_ref[NET_TX_RING_SIZE];
unsigned tx_skb_freelist;
+ spinlock_t rx_lock ____cacheline_aligned_in_smp;
+ struct xen_netif_rx_front_ring rx;
+ int rx_ring_ref;
+
+ /* Receive-ring batched refills. */
+#define RX_MIN_TARGET 8
+#define RX_DFL_MIN_TARGET 64
+#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
+ unsigned rx_min_target, rx_max_target, rx_target;
+ struct sk_buff_head rx_batch;
+
+ struct timer_list rx_refill_timer;
+
struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
grant_ref_t gref_rx_head;
grant_ref_t grant_rx_ref[NET_RX_RING_SIZE];
-
- struct xenbus_device *xbdev;
- int tx_ring_ref;
- int rx_ring_ref;
unsigned long rx_pfn_array[NET_RX_RING_SIZE];
struct multicall_entry rx_mcl[NET_RX_RING_SIZE+1];
-
