diff options
Diffstat (limited to 'drivers/net/xen-netback')
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 72314c7998fc..573f3e81e5d2 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -493,9 +493,28 @@ static void xenvif_rx_action(struct xenvif *vif) PAGE_SIZE); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { unsigned int size; + unsigned int offset; + size = skb_frag_size(&skb_shinfo(skb)->frags[i]); - max_slots_needed += DIV_ROUND_UP(size, PAGE_SIZE); + offset = skb_shinfo(skb)->frags[i].page_offset; + + /* For a worse-case estimate we need to factor in + * the fragment page offset as this will affect the + * number of times xenvif_gop_frag_copy() will + * call start_new_rx_buffer(). + */ + max_slots_needed += DIV_ROUND_UP(offset + size, + PAGE_SIZE); } + + /* To avoid the estimate becoming too pessimal for some + * frontends that limit posted rx requests, cap the estimate + * at MAX_SKB_FRAGS. + */ + if (max_slots_needed > MAX_SKB_FRAGS) + max_slots_needed = MAX_SKB_FRAGS; + + /* We may need one more slot for GSO metadata */ if (skb_is_gso(skb) && (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4 || skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6)) |