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authorPaolo Abeni <pabeni@redhat.com>2016-09-30 16:56:45 +0200
committerDavid S. Miller <davem@davemloft.net>2016-10-03 01:29:57 -0400
commit63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d (patch)
tree57c39b309be4ed7e304e956d3fb0035d2a291e00
parentb82d44d78480faff7456e9e0999acb9d38666057 (diff)
downloadlinux-stericsson-63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d.tar.gz
net: pktgen: fix pkt_size
The commit 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") increased the 'pkt_overhead' field value by LL_RESERVED_SPACE. As a side effect the generated packet size, computed as: /* Eth + IPh + UDPh + mpls */ datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - pkt_dev->pkt_overhead; is decreased by the same value. The above changed slightly the behavior of existing pktgen users, and made the procfs interface somewhat inconsistent. Fix it by restoring the previous pkt_overhead value and using LL_RESERVED_SPACE as extralen in skb allocation. Also, change pktgen_alloc_skb() to only partially reserve the headroom to allow the caller to prefetch from ll header start. v1 -> v2: - fixed some typos in the comments Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") Suggested-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/pktgen.c21
1 files changed, 10 insertions, 11 deletions
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index bbd118b19aef..5219a9e2127a 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2286,7 +2286,7 @@ out:
static inline void set_pkt_overhead(struct pktgen_dev *pkt_dev)
{
- pkt_dev->pkt_overhead = LL_RESERVED_SPACE(pkt_dev->odev);
+ pkt_dev->pkt_overhead = 0;
pkt_dev->pkt_overhead += pkt_dev->nr_labels*sizeof(u32);
pkt_dev->pkt_overhead += VLAN_TAG_SIZE(pkt_dev);
pkt_dev->pkt_overhead += SVLAN_TAG_SIZE(pkt_dev);
@@ -2777,13 +2777,13 @@ static void pktgen_finalize_skb(struct pktgen_dev *pkt_dev, struct sk_buff *skb,
}
static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
- struct pktgen_dev *pkt_dev,
- unsigned int extralen)
+ struct pktgen_dev *pkt_dev)
{
+ unsigned int extralen = LL_RESERVED_SPACE(dev);
struct sk_buff *skb = NULL;
- unsigned int size = pkt_dev->cur_pkt_size + 64 + extralen +
- pkt_dev->pkt_overhead;
+ unsigned int size;
+ size = pkt_dev->cur_pkt_size + 64 + extralen + pkt_dev->pkt_overhead;
if (pkt_dev->flags & F_NODE) {
int node = pkt_dev->node >= 0 ? pkt_dev->node : numa_node_id();
@@ -2796,8 +2796,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT);
}
+ /* the caller pre-fetches from skb->data and reserves for the mac hdr */
if (likely(skb))
- skb_reserve(skb, LL_RESERVED_SPACE(dev));
+ skb_reserve(skb, extralen - 16);
return skb;
}
@@ -2830,16 +2831,14 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
mod_cur_headers(pkt_dev);
queue_map = pkt_dev->cur_queue_map;
- datalen = (odev->hard_header_len + 16) & ~0xf;
-
- skb = pktgen_alloc_skb(odev, pkt_dev, datalen);
+ skb = pktgen_alloc_skb(odev, pkt_dev);
if (!skb) {
sprintf(pkt_dev->result, "No memory");
return NULL;
}
prefetchw(skb->data);
- skb_reserve(skb, datalen);
+ skb_reserve(skb, 16);
/* Reserve for ethernet and IP header */
eth = (__u8 *) skb_push(skb, 14);
@@ -2959,7 +2958,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
mod_cur_headers(pkt_dev);
queue_map = pkt_dev->cur_queue_map;
- skb = pktgen_alloc_skb(odev, pkt_dev, 16);
+ skb = pktgen_alloc_skb(odev, pkt_dev);
if (!skb) {
sprintf(pkt_dev->result, "No memory");
return NULL;