Following patch cleanup hh_cache access by avoiding hh
pointer fetching most of time. Now hh is read and checked at beginning
of function. All hh->hh_len access are done inside hh_lock.
This is required cleanup for next patch which adds support for kernel
3.1.
Suggested-by: Jesse Gross <je...@nicira.com>
Signed-off-by: Pravin Shelar <pshe...@nicira.com>
---
datapath/tunnel.c | 49 +++++++++++++++++++++++++++++++------------------
datapath/tunnel.h | 1 +
2 files changed, 32 insertions(+), 18 deletions(-)
diff --git a/datapath/tunnel.c b/datapath/tunnel.c
index 8edff06..b750bbc 100644
--- a/datapath/tunnel.c
+++ b/datapath/tunnel.c
@@ -743,7 +743,13 @@ static inline void *get_cached_header(const struct
tnl_cache *cache)
static inline bool check_cache_valid(const struct tnl_cache *cache,
const struct tnl_mutable_config *mutable)
{
- return cache &&
+ struct hh_cache *hh;
+
+ if (!cache)
+ return false;
+
+ hh = rt_dst(cache->rt).hh;
+ return hh &&
#ifdef NEED_CACHE_TIMEOUT
time_before(jiffies, cache->expiration) &&
#endif
@@ -751,7 +757,7 @@ static inline bool check_cache_valid(const struct tnl_cache
*cache,
atomic_read(&init_net.ipv4.rt_genid) == cache->rt->rt_genid &&
#endif
#ifdef HAVE_HH_SEQ
- rt_dst(cache->rt).hh->hh_lock.sequence == cache->hh_seq &&
+ hh->hh_lock.sequence == cache->hh_seq &&
#endif
mutable->seq == cache->mutable_seq &&
(!is_internal_dev(rt_dst(cache->rt).dev) ||
@@ -791,25 +797,30 @@ static void cache_cleaner(struct work_struct *work)
}
static inline void create_eth_hdr(struct tnl_cache *cache,
- const struct rtable *rt)
+ struct hh_cache *hh)
{
void *cache_data = get_cached_header(cache);
- int hh_len = rt_dst(rt).hh->hh_len;
- int hh_off = HH_DATA_ALIGN(rt_dst(rt).hh->hh_len) - hh_len;
+ int hh_off;
#ifdef HAVE_HH_SEQ
unsigned hh_seq;
do {
- hh_seq = read_seqbegin(&rt_dst(rt).hh->hh_lock);
- memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off,
hh_len);
- } while (read_seqretry(&rt_dst(rt).hh->hh_lock, hh_seq));
+
+ hh_off = HH_DATA_ALIGN(hh->hh_len) - hh->hh_len;
+
+ hh_seq = read_seqbegin(&hh->hh_lock);
+ memcpy(cache_data, (void *)hh->hh_data + hh_off, hh->hh_len);
+ cache->hh_len = hh->hh_len;
+ } while (read_seqretry(&hh->hh_lock, hh_seq));
cache->hh_seq = hh_seq;
#else
- read_lock(&rt_dst(rt).hh->hh_lock);
- memcpy(cache_data, (void *)rt_dst(rt).hh->hh_data + hh_off, hh_len);
- read_unlock(&rt_dst(rt).hh->hh_lock);
+ read_lock(&hh->hh_lock);
+ hh_off = HH_DATA_ALIGN(hh->hh_len) - hh->hh_len;
+ memcpy(cache_data, (void *)hh->hh_data + hh_off, hh->hh_len);
+ cache->hh_len = hh->hh_len;
+ read_unlock(&hh->hh_lock);
#endif
}
@@ -821,6 +832,7 @@ static struct tnl_cache *build_cache(struct vport *vport,
struct tnl_cache *cache;
void *cache_data;
int cache_len;
+ struct hh_cache *hh;
if (!(mutable->flags & TNL_F_HDR_CACHE))
return NULL;
@@ -829,7 +841,9 @@ static struct tnl_cache *build_cache(struct vport *vport,
* If there is no entry in the ARP cache or if this device does not
* support hard header caching just fall back to the IP stack.
*/
- if (!rt_dst(rt).hh)
+
+ hh = rt_dst(rt).hh;
+ if (!hh)
return NULL;
/*
@@ -845,17 +859,16 @@ static struct tnl_cache *build_cache(struct vport *vport,
else
cache = NULL;
- cache_len = rt_dst(rt).hh->hh_len + mutable->tunnel_hlen;
+ cache_len = LL_RESERVED_SPACE(rt_dst(rt).dev) + mutable->tunnel_hlen;
cache = kzalloc(ALIGN(sizeof(struct tnl_cache), CACHE_DATA_ALIGN) +
cache_len, GFP_ATOMIC);
if (!cache)
goto unlock;
- cache->len = cache_len;
-
- create_eth_hdr(cache, rt);
- cache_data = get_cached_header(cache) + rt_dst(rt).hh->hh_len;
+ create_eth_hdr(cache, hh);
+ cache_data = get_cached_header(cache) + cache->hh_len;
+ cache->len = cache->hh_len + mutable->tunnel_hlen;
create_tunnel_header(vport, mutable, rt, cache_data);
@@ -1181,7 +1194,7 @@ int tnl_send(struct vport *vport, struct sk_buff *skb)
skb_push(skb, cache->len);
memcpy(skb->data, get_cached_header(cache), cache->len);
skb_reset_mac_header(skb);
- skb_set_network_header(skb, rt_dst(rt).hh->hh_len);
+ skb_set_network_header(skb, cache->hh_len);
} else {
skb_push(skb, mutable->tunnel_hlen);
diff --git a/datapath/tunnel.h b/datapath/tunnel.h
index 8d20c77..0ab0390 100644
--- a/datapath/tunnel.h
+++ b/datapath/tunnel.h
@@ -148,6 +148,7 @@ struct tnl_cache {
struct rcu_head rcu;
int len; /* Length of data to be memcpy'd from cache. */
+ int hh_len;
/* Sequence number of mutable->seq from which this cache was generated.
*/
unsigned mutable_seq;
--
1.7.1
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