From f6b72b6217f8c24f2a54988e58af858b4e66024d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 14 Jul 2011 07:53:20 -0700 Subject: net: Embed hh_cache inside of struct neighbour. Now that there is a one-to-one correspondance between neighbour and hh_cache entries, we no longer need: 1) dynamic allocation 2) attachment to dst->hh 3) refcounting Initialization of the hh_cache entry is indicated by hh_len being non-zero, and such initialization is always done with the neighbour's lock held as a writer. Signed-off-by: David S. Miller --- include/linux/netdevice.h | 15 +-------------- include/net/dst.h | 18 +++++++++--------- include/net/neighbour.h | 2 +- 3 files changed, 11 insertions(+), 24 deletions(-) (limited to 'include') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 7538237..5ccc0cb 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -252,14 +252,7 @@ struct netdev_hw_addr_list { netdev_hw_addr_list_for_each(ha, &(dev)->mc) struct hh_cache { - atomic_t hh_refcnt; /* number of users */ -/* - * We want hh_output, hh_len, hh_lock and hh_data be a in a separate - * cache line on SMP. - * They are mostly read, but hh_refcnt may be changed quite frequently, - * incurring cache line ping pongs. - */ - u16 hh_len ____cacheline_aligned_in_smp; + u16 hh_len; u16 __pad; int (*hh_output)(struct sk_buff *skb); seqlock_t hh_lock; @@ -273,12 +266,6 @@ struct hh_cache { unsigned long hh_data[HH_DATA_ALIGN(LL_MAX_HEADER) / sizeof(long)]; }; -static inline void hh_cache_put(struct hh_cache *hh) -{ - if (atomic_dec_and_test(&hh->hh_refcnt)) - kfree(hh); -} - /* Reserve HH_DATA_MOD byte aligned hard_header_len, but at least that much. * Alternative is: * dev->hard_header_len ? (dev->hard_header_len + diff --git a/include/net/dst.h b/include/net/dst.h index e12ddfb..0dd7ccb 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -38,7 +38,6 @@ struct dst_entry { unsigned long expires; struct dst_entry *path; struct neighbour *neighbour; - struct hh_cache *hh; #ifdef CONFIG_XFRM struct xfrm_state *xfrm; #else @@ -47,6 +46,14 @@ struct dst_entry { int (*input)(struct sk_buff*); int (*output)(struct sk_buff*); + int flags; +#define DST_HOST 0x0001 +#define DST_NOXFRM 0x0002 +#define DST_NOPOLICY 0x0004 +#define DST_NOHASH 0x0008 +#define DST_NOCACHE 0x0010 +#define DST_NOCOUNT 0x0020 + short error; short obsolete; unsigned short header_len; /* more space at head required */ @@ -62,7 +69,7 @@ struct dst_entry { * (L1_CACHE_SIZE would be too much) */ #ifdef CONFIG_64BIT - long __pad_to_align_refcnt[1]; + long __pad_to_align_refcnt[2]; #endif /* * __refcnt wants to be on a different cache line from @@ -71,13 +78,6 @@ struct dst_entry { atomic_t __refcnt; /* client references */ int __use; unsigned long lastuse; - int flags; -#define DST_HOST 0x0001 -#define DST_NOXFRM 0x0002 -#define DST_NOPOLICY 0x0004 -#define DST_NOHASH 0x0008 -#define DST_NOCACHE 0x0010 -#define DST_NOCOUNT 0x0020 union { struct dst_entry *next; struct rtable __rcu *rt_next; diff --git a/include/net/neighbour.h b/include/net/neighbour.h index 6fe8c2c..bd8f9f0 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -108,7 +108,7 @@ struct neighbour { __u8 dead; seqlock_t ha_lock; unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; - struct hh_cache *hh; + struct hh_cache hh; int (*output)(struct sk_buff *skb); const struct neigh_ops *ops; struct rcu_head rcu; -- cgit v1.1