[PATCH v4 01/20] net/xen-netback: xenvif_gop_frag_copy: move GSO check out of the loop

From: Julien Grall
Date: Mon Sep 07 2015 - 11:36:24 EST


The skb doesn't change within the function. Therefore it's only
necessary to check if we need GSO once at the beginning.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>

---
Cc: Ian Campbell <ian.campbell@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx

Changes in v4:
- Add Wei's acked

Changes in v2:
- Patch added
---
drivers/net/xen-netback/netback.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 7c64c74..d4c1bc7 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -277,6 +277,13 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
unsigned long bytes;
int gso_type = XEN_NETIF_GSO_TYPE_NONE;

+ if (skb_is_gso(skb)) {
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
+ else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
+ gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
+ }
+
/* Data must not cross a page boundary. */
BUG_ON(size + offset > PAGE_SIZE<<compound_order(page));

@@ -336,13 +343,6 @@ static void xenvif_gop_frag_copy(struct xenvif_queue *queue, struct sk_buff *skb
}

/* Leave a gap for the GSO descriptor. */
- if (skb_is_gso(skb)) {
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV4;
- else if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)
- gso_type = XEN_NETIF_GSO_TYPE_TCPV6;
- }
-
if (*head && ((1 << gso_type) & queue->vif->gso_mask))
queue->rx.req_cons++;

--
2.1.4

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