xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: core: rework basic flow dissection helper

Browse Source 
When the core networking needs to detect the transport offset in a given
packet and parse it explicitly, a full-blown flow_keys struct is used for
storage.
This patch introduces a smaller keys store, rework the basic flow dissect
helper to use it, and apply this new helper where possible - namely in
skb_probe_transport_header(). The used flow dissector data structures
are renamed to match more closely the new role.

The above gives ~50% performance improvement in micro benchmarking around
skb_probe_transport_header() and ~30% around eth_get_headlen(), mostly due
to the smaller memset. Small, but measurable improvement is measured also
in macro benchmarking.

v1 -> v2: use the new helper in eth_get_headlen() and skb_get_poff(),
  as per DaveM suggestion

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Paolo Abeni
2018-05-04 11:32:59 +02:00
committed by David S. Miller
parent 62515f95b4
commit 72a338bcc6
4 changed files with 28 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
include/linux/skbuff.h
View File

@@ -1171,7 +1171,7 @@ void __skb_get_hash(struct sk_buff *skb);
u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
u32 skb_get_poff(const struct sk_buff *skb);
u32 __skb_get_poff(const struct sk_buff *skb, void *data,
const struct flow_keys *keys, int hlen);
const struct flow_keys_basic *keys, int hlen);
__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
void *data, int hlen_proto);
@@ -1208,13 +1208,14 @@ static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
NULL, 0, 0, 0, flags);
}
static inline bool skb_flow_dissect_flow_keys_buf(struct flow_keys *flow,
void *data, __be16 proto,
int nhoff, int hlen,
unsigned int flags)
static inline bool
skb_flow_dissect_flow_keys_basic(const struct sk_buff *skb,
struct flow_keys_basic *flow, void *data,
__be16 proto, int nhoff, int hlen,
unsigned int flags)
{
memset(flow, 0, sizeof(*flow));
return __skb_flow_dissect(NULL, &flow_keys_buf_dissector, flow,
return __skb_flow_dissect(skb, &flow_keys_basic_dissector, flow,
data, proto, nhoff, hlen, flags);
}
@@ -2350,11 +2351,12 @@ static inline void skb_pop_mac_header(struct sk_buff *skb)
static inline void skb_probe_transport_header(struct sk_buff *skb,
const int offset_hint)
{
struct flow_keys keys;
struct flow_keys_basic keys;
if (skb_transport_header_was_set(skb))
return;
else if (skb_flow_dissect_flow_keys(skb, &keys, 0))
if (skb_flow_dissect_flow_keys_basic(skb, &keys, 0, 0, 0, 0, 0))
skb_set_transport_header(skb, keys.control.thoff);
else
skb_set_transport_header(skb, offset_hint);