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| author | Paolo Abeni <pabeni@redhat.com> | 2016-09-30 17:56:45 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-10-03 08:29:57 +0300 |
| commit | 63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d (patch) | |
| tree | 57c39b309be4ed7e304e956d3fb0035d2a291e00 /net/core | |
| parent | b82d44d78480faff7456e9e0999acb9d38666057 (diff) | |
| download | linux-63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d.tar.xz | |
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>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/pktgen.c | 21 |
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; |