diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2016-10-13 18:26:56 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-10-14 10:54:53 -0400 |
| commit | fc791b6335152c5278dc4a4991bcb2d329f806f9 (patch) | |
| tree | a7d55fc9472c953a24cdd4c2c59f917b389c2e96 /drivers/infiniband/ulp/ipoib/ipoib.h | |
| parent | f1f081cef09697d97f20ea6b8b545b1b61613880 (diff) | |
IB/ipoib: move back IB LL address into the hard header
After the commit 9207f9d45b0a ("net: preserve IP control block
during GSO segmentation"), the GSO CB and the IPoIB CB conflict.
That destroy the IPoIB address information cached there,
causing a severe performance regression, as better described here:
http://marc.info/?l=linux-kernel&m=146787279825501&w=2
This change moves the data cached by the IPoIB driver from the
skb control lock into the IPoIB hard header, as done before
the commit 936d7de3d736 ("IPoIB: Stop lying about hard_header_len
and use skb->cb to stash LL addresses").
In order to avoid GRO issue, on packet reception, the IPoIB driver
stash into the skb a dummy pseudo header, so that the received
packets have actually a hard header matching the declared length.
To avoid changing the connected mode maximum mtu, the allocated
head buffer size is increased by the pseudo header length.
After this commit, IPoIB performances are back to pre-regression
value.
v2 -> v3: rebased
v1 -> v2: avoid changing the max mtu, increasing the head buf size
Fixes: 9207f9d45b0a ("net: preserve IP control block during GSO segmentation")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/infiniband/ulp/ipoib/ipoib.h')
| -rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib.h | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h index 7b8d2d9e2263..da12717a3eb7 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib.h +++ b/drivers/infiniband/ulp/ipoib/ipoib.h @@ -63,6 +63,8 @@ enum ipoib_flush_level { enum { IPOIB_ENCAP_LEN = 4, + IPOIB_PSEUDO_LEN = 20, + IPOIB_HARD_LEN = IPOIB_ENCAP_LEN + IPOIB_PSEUDO_LEN, IPOIB_UD_HEAD_SIZE = IB_GRH_BYTES + IPOIB_ENCAP_LEN, IPOIB_UD_RX_SG = 2, /* max buffer needed for 4K mtu */ @@ -134,15 +136,21 @@ struct ipoib_header { u16 reserved; }; -struct ipoib_cb { - struct qdisc_skb_cb qdisc_cb; - u8 hwaddr[INFINIBAND_ALEN]; +struct ipoib_pseudo_header { + u8 hwaddr[INFINIBAND_ALEN]; }; -static inline struct ipoib_cb *ipoib_skb_cb(const struct sk_buff *skb) +static inline void skb_add_pseudo_hdr(struct sk_buff *skb) { - BUILD_BUG_ON(sizeof(skb->cb) < sizeof(struct ipoib_cb)); - return (struct ipoib_cb *)skb->cb; + char *data = skb_push(skb, IPOIB_PSEUDO_LEN); + + /* + * only the ipoib header is present now, make room for a dummy + * pseudo header and set skb field accordingly + */ + memset(data, 0, IPOIB_PSEUDO_LEN); + skb_reset_mac_header(skb); + skb_pull(skb, IPOIB_HARD_LEN); } /* Used for all multicast joins (broadcast, IPv4 mcast and IPv6 mcast) */ |