The addition of Geneve metadata requires a large amount of additional
space to handle the maximum set of options. In most cases, this is
not a big deal since it is only temporary storage on the stack or
can be automatically stripped out for miniflows. However, userspace
tunnels need to deal with this on a per-packet basis, so we should
avoid introducing additional overhead if possible. Two small changes
are aimed at this:
* Move struct flow_tnl to the end of the packet metadata. Since
the Geneve metadata is already at the end of flow_tnl and pkt_metadata
is at the end of struct dp_packet, this avoids putting a large
amount metadata (which might be empty) in hot cache lines.
* Only push the new metadata into a miniflow if any options are present
during miniflow_extract(). This does not necessarily provide the
most fine-grained flow generation but it is a quick check and
the userspace implementation of Geneve does not currently support
options anyways.
Signed-off-by: Jesse Gross <je...@nicira.com>
---
lib/flow.c | 7 ++++++-
lib/packets.h | 2 +-
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/lib/flow.c b/lib/flow.c
index 7350a17..6bfe738 100644
--- a/lib/flow.c
+++ b/lib/flow.c
@@ -438,7 +438,12 @@ miniflow_extract(struct dp_packet *packet, struct miniflow
*dst)
/* Metadata. */
if (md->tunnel.ip_dst) {
miniflow_push_words(mf, tunnel, &md->tunnel,
- sizeof md->tunnel / sizeof(uint64_t));
+ offsetof(struct flow_tnl, metadata) /
+ sizeof(uint64_t));
+ if (md->tunnel.metadata.opt_map) {
+ miniflow_push_words(mf, tunnel.metadata, &md->tunnel.metadata,
+ sizeof md->tunnel.metadata /
sizeof(uint64_t));
+ }
}
if (md->skb_priority || md->pkt_mark) {
miniflow_push_uint32(mf, skb_priority, md->skb_priority);
diff --git a/lib/packets.h b/lib/packets.h
index 688e7373..04ee914 100644
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -63,10 +63,10 @@ struct pkt_metadata {
received from the wire. */
uint32_t dp_hash; /* hash value computed by the recirculation
action. */
- struct flow_tnl tunnel; /* Encapsulating tunnel parameters. */
uint32_t skb_priority; /* Packet priority for QoS. */
uint32_t pkt_mark; /* Packet mark. */
union flow_in_port in_port; /* Input port. */
+ struct flow_tnl tunnel; /* Encapsulating tunnel parameters. */
};
#define PKT_METADATA_INITIALIZER(PORT) \
--
2.1.0
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