diff options
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index c57088f..6be767c 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -193,13 +193,20 @@ struct hh_cache { struct hh_cache *hh_next; /* Next entry */ atomic_t hh_refcnt; /* number of users */ - __be16 hh_type; /* protocol identifier, f.e ETH_P_IP +/* + * 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. + */ + __be16 hh_type ____cacheline_aligned_in_smp; + /* protocol identifier, f.e ETH_P_IP * NOTE: For VLANs, this will be the * encapuslated type. --BLG */ u16 hh_len; /* length of header */ int (*hh_output)(struct sk_buff *skb); - rwlock_t hh_lock; + seqlock_t hh_lock; /* cached hardware header; allow for machine alignment needs. */ #define HH_DATA_MOD 16 |
