From af12fa6e46aa651e7b86a4c4117b562518fef184 Mon Sep 17 00:00:00 2001 From: Eliezer Tamir Date: Mon, 10 Jun 2013 11:39:41 +0300 Subject: net: add napi_id and hash Adds a napi_id and a hashing mechanism to lookup a napi by id. This will be used by subsequent patches to implement low latency Ethernet device polling. Based on a code sample by Eric Dumazet. Signed-off-by: Eliezer Tamir Signed-off-by: Eric Dumazet Tested-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/netdevice.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8f967e34142b..39bbd462d68e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -324,12 +324,15 @@ struct napi_struct { struct sk_buff *gro_list; struct sk_buff *skb; struct list_head dev_list; + struct hlist_node napi_hash_node; + unsigned int napi_id; }; enum { NAPI_STATE_SCHED, /* Poll is scheduled */ NAPI_STATE_DISABLE, /* Disable pending */ NAPI_STATE_NPSVC, /* Netpoll - don't dequeue from poll_list */ + NAPI_STATE_HASHED, /* In NAPI hash */ }; enum gro_result { @@ -445,6 +448,32 @@ static inline bool napi_reschedule(struct napi_struct *napi) extern void __napi_complete(struct napi_struct *n); extern void napi_complete(struct napi_struct *n); +/** + * napi_by_id - lookup a NAPI by napi_id + * @napi_id: hashed napi_id + * + * lookup @napi_id in napi_hash table + * must be called under rcu_read_lock() + */ +extern struct napi_struct *napi_by_id(unsigned int napi_id); + +/** + * napi_hash_add - add a NAPI to global hashtable + * @napi: napi context + * + * generate a new napi_id and store a @napi under it in napi_hash + */ +extern void napi_hash_add(struct napi_struct *napi); + +/** + * napi_hash_del - remove a NAPI from global table + * @napi: napi context + * + * Warning: caller must observe rcu grace period + * before freeing memory containing @napi + */ +extern void napi_hash_del(struct napi_struct *napi); + /** * napi_disable - prevent NAPI from scheduling * @n: napi context -- cgit v1.2.3