Skip to contentSkip to conversation

xen-netfront: rearrange netfront_info structure to separate tx and rx

PATCH In review Jeremy Fitzhardinge 2 participants 4 messages Oct 9, 2007 – Oct 10, 2007

Subsystems (3)
lore
Share & tools
lore
#0 lore raw

PATCH 1/1 xen-netfront: rearrange netfront_info structure to separate tx and rx

Keep tx and rx elements separate on different cachelines to prevent bouncing.

Cc Stephen Hemminger <[email protected]>
Cc Christoph Hellwig <[email protected]>
---
 drivers/net/xen-netfront.c |   37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

===================================================================

drivers/net/xen-netfront.c +18 -19
@@ -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];
#1 lore raw
Quoted 10 lines · Jeremy Fitzhardinge

Keep tx and rx elements separate on different cachelines to prevent bouncing.

Cc Stephen Hemminger <[email protected]>
Cc Christoph Hellwig <[email protected]>
---
 drivers/net/xen-netfront.c |   37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

ACK but does not apply to jgarzik/netdev-2.6.git#upstream nor davem/net-2.6.24.git

#2 lore raw
Quoted 8 lines · Jeff Garzik
Quoted 7 lines · Jeremy Fitzhardinge

Keep tx and rx elements separate on different cachelines to prevent bouncing.

Cc Stephen Hemminger <[email protected]>
Cc Christoph Hellwig <[email protected]>
Quoted 6 lines
Quoted 3 lines
---
 drivers/net/xen-netfront.c |   37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

ACK but does not apply to jgarzik/netdev-2.6.git#upstream nor davem/net-2.6.24.git

Oh, OK, I'll have a look. I wasn't aware of any other changes in xen-netfront. Or rather, there are a couple of other changes which I think you already have: one to use the common netdev stats structure, and another to remove a chunk of dead code.

J

#3 lore raw
In reply to Jeff Garzik
Quoted 2 lines · Jeff Garzik

ACK but does not apply to jgarzik/netdev-2.6.git#upstream nor davem/net-2.6.24.git

OK, looks like you don't have the other two patches. Will post in a sec.

J