Xen devel - Mar 2013 - [PATCH 3/6] xen-netfront: frags -> slots in xennet_get_responses

This function is in fact counting the ring slots required for responses.
Separate the concepts of ring slots and skb frags make the code clearer, as
now netfront and netback can have different MAX_SKB_FRAGS, slot and frag are
not mapped 1:1 any more.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 drivers/net/xen-netfront.c |   18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 3ae9dc1..52f5010 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -724,7 +724,7 @@ static int xennet_get_responses(struct netfront_info *np,
 	struct sk_buff *skb = xennet_get_rx_skb(np, cons);
 	grant_ref_t ref = xennet_get_rx_ref(np, cons);
 	int max = MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD);
-	int frags = 1;
+	int slots = 1;
 	int err = 0;
 	unsigned long ret;
 
@@ -768,27 +768,27 @@ next:
 		if (!(rx->flags & XEN_NETRXF_more_data))
 			break;
 
-		if (cons + frags == rp) {
+		if (cons + slots == rp) {
 			if (net_ratelimit())
-				dev_warn(dev, "Need more frags\n");
+				dev_warn(dev, "Need more slots\n");
 			err = -ENOENT;
 			break;
 		}
 
-		rx = RING_GET_RESPONSE(&np->rx, cons + frags);
-		skb = xennet_get_rx_skb(np, cons + frags);
-		ref = xennet_get_rx_ref(np, cons + frags);
-		frags++;
+		rx = RING_GET_RESPONSE(&np->rx, cons + slots);
+		skb = xennet_get_rx_skb(np, cons + slots);
+		ref = xennet_get_rx_ref(np, cons + slots);
+		slots++;
 	}
 
-	if (unlikely(frags > max)) {
+	if (unlikely(slots > max)) {
 		if (net_ratelimit())
 			dev_warn(dev, "Too many frags\n");
 		err = -E2BIG;
 	}
 
 	if (unlikely(err))
-		np->rx.rsp_cons = cons + frags;
+		np->rx.rsp_cons = cons + slots;
 
 	return err;
 }
-- 
1.7.10.4

On 25/03/13 11:08, Wei Liu wrote:
> This function is in fact counting the ring slots required for responses.
> Separate the concepts of ring slots and skb frags make the code clearer, as
> now netfront and netback can have different MAX_SKB_FRAGS, slot and frag
are
> not mapped 1:1 any more.
> 
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Makes sense.

Reviewed-by: David Vrabel <david.vrabel@citrix.com>

David

From: Wei Liu <wei.liu2@citrix.com>
Date: Mon, 25 Mar 2013 11:08:19 +0000
> This function is in fact counting the ring slots required for responses.
> Separate the concepts of ring slots and skb frags make the code clearer, as
> now netfront and netback can have different MAX_SKB_FRAGS, slot and frag
are
> not mapped 1:1 any more.
> 
> Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Applied.