diff options
Diffstat (limited to 'include/net/dst.h')
| -rw-r--r-- | include/net/dst.h | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index d67fda89cd0f..78884429deed 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -16,6 +16,7 @@ #include <linux/bug.h> #include <linux/jiffies.h> #include <linux/refcount.h> +#include <linux/rcuref.h> #include <net/neighbour.h> #include <asm/processor.h> #include <linux/indirect_call_wrapper.h> @@ -61,23 +62,36 @@ struct dst_entry { unsigned short trailer_len; /* space to reserve at tail */ /* - * __refcnt wants to be on a different cache line from + * __rcuref wants to be on a different cache line from * input/output/ops or performance tanks badly */ #ifdef CONFIG_64BIT - atomic_t __refcnt; /* 64-bit offset 64 */ + rcuref_t __rcuref; /* 64-bit offset 64 */ #endif int __use; unsigned long lastuse; - struct lwtunnel_state *lwtstate; struct rcu_head rcu_head; short error; short __pad; __u32 tclassid; #ifndef CONFIG_64BIT - atomic_t __refcnt; /* 32-bit offset 64 */ + struct lwtunnel_state *lwtstate; + rcuref_t __rcuref; /* 32-bit offset 64 */ #endif netdevice_tracker dev_tracker; + + /* + * Used by rtable and rt6_info. Moves lwtstate into the next cache + * line on 64bit so that lwtstate does not cause false sharing with + * __rcuref under contention of __rcuref. This also puts the + * frequently accessed members of rtable and rt6_info out of the + * __rcuref cache line. + */ + struct list_head rt_uncached; + struct uncached_list *rt_uncached_list; +#ifdef CONFIG_64BIT + struct lwtunnel_state *lwtstate; +#endif }; struct dst_metrics { @@ -225,10 +239,10 @@ static inline void dst_hold(struct dst_entry *dst) { /* * If your kernel compilation stops here, please check - * the placement of __refcnt in struct dst_entry + * the placement of __rcuref in struct dst_entry */ - BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); - WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0); + BUILD_BUG_ON(offsetof(struct dst_entry, __rcuref) & 63); + WARN_ON(!rcuref_get(&dst->__rcuref)); } static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) @@ -292,7 +306,7 @@ static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb */ static inline bool dst_hold_safe(struct dst_entry *dst) { - return atomic_inc_not_zero(&dst->__refcnt); + return rcuref_get(&dst->__rcuref); } /** |