[NETBACK] Try to pull a minimum of 72 bytes into the skb data area

when receiving a packet into netback.  The previous number, 64, tended
to place a fragment boundary in the middle of the TCP header options
and led to unnecessary fragmentation in Windows <-> Windows
networking.

Signed-off-by: Steven Smith <ssmith@xensource.com>

diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index a17f166a19dc355f91e755f0b380ef419bf10b93..78e3cfbea26abedc64ae00b809cb1c8a3bce863a 100644 (file)
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -105,7 +105,7 @@ static inline int netif_page_index(struct page *pg)
        return idx;
 }
 
-#define PKT_PROT_LEN 64
+#define PKT_PROT_LEN 72
 
 static struct pending_tx_info {
        netif_tx_request_t req;