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authorTom Herbert <therbert@google.com>2011-08-14 19:46:29 +0000
committerDavid S. Miller <davem@davemloft.net>2011-08-17 20:06:03 -0700
commitc6865cb3cc6f3c2857fa4c6f5fda2945d70b1e84 (patch)
tree2c575583ebc973f56714d5ab6751b8745972fd6f
parentrps: Infrastructure in __skb_get_rxhash for deep inspection (diff)
downloadlinux-dev-c6865cb3cc6f3c2857fa4c6f5fda2945d70b1e84.tar.xz
linux-dev-c6865cb3cc6f3c2857fa4c6f5fda2945d70b1e84.zip
rps: Inspect GRE encapsulated packets to get flow hash
Crack open GRE packets in __skb_get_rxhash to compute 4-tuple hash on in encapsulated packet. Note that this is used only when the __skb_get_rxhash is taken, in particular only when the device does not compute provide the rxhash (ie. feature is disabled). This was tested by creating a single GRE tunnel between two 16 core AMD machines. 200 netperf TCP_RR streams were ran with 1 byte request and response size. Without patch: 157497 tps, 50/90/99% latencies 1250/1292/1364 usecs With patch: 325896 tps, 50/90/99% latencies 603/848/1169 Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/core/dev.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 4bee9a9aeef6..a8d91a5dd909 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2570,6 +2570,28 @@ again:
}
switch (ip_proto) {
+ case IPPROTO_GRE:
+ if (pskb_may_pull(skb, nhoff + 16)) {
+ u8 *h = skb->data + nhoff;
+ __be16 flags = *(__be16 *)h;
+
+ /*
+ * Only look inside GRE if version zero and no
+ * routing
+ */
+ if (!(flags & (GRE_VERSION|GRE_ROUTING))) {
+ proto = *(__be16 *)(h + 2);
+ nhoff += 4;
+ if (flags & GRE_CSUM)
+ nhoff += 4;
+ if (flags & GRE_KEY)
+ nhoff += 4;
+ if (flags & GRE_SEQ)
+ nhoff += 4;
+ goto again;
+ }
+ }
+ break;
default:
break;
}