Subject: net: Use skbufhead with raw lock From: Thomas Gleixner Date: Tue Jul 12 15:38:34 2011 +0200 From: Thomas Gleixner Use the rps lock as rawlock so we can keep irq-off regions. It looks low latency. However we can't kfree() from this context therefore we defer this to the softirq and use the tofree_queue list for it (similar to process_queue). Signed-off-by: Thomas Gleixner --- include/linux/skbuff.h | 7 +++++++ net/core/dev.c | 6 +++--- 2 files changed, 10 insertions(+), 3 deletions(-) --- --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -297,6 +297,7 @@ struct sk_buff_head { __u32 qlen; spinlock_t lock; + raw_spinlock_t raw_lock; }; struct sk_buff; @@ -1916,6 +1917,12 @@ static inline void skb_queue_head_init(s __skb_queue_head_init(list); } +static inline void skb_queue_head_init_raw(struct sk_buff_head *list) +{ + raw_spin_lock_init(&list->raw_lock); + __skb_queue_head_init(list); +} + static inline void skb_queue_head_init_class(struct sk_buff_head *list, struct lock_class_key *class) { --- a/net/core/dev.c +++ b/net/core/dev.c @@ -225,14 +225,14 @@ static inline struct hlist_head *dev_ind static inline void rps_lock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_lock(&sd->input_pkt_queue.lock); + raw_spin_lock(&sd->input_pkt_queue.raw_lock); #endif } static inline void rps_unlock(struct softnet_data *sd) { #ifdef CONFIG_RPS - spin_unlock(&sd->input_pkt_queue.lock); + raw_spin_unlock(&sd->input_pkt_queue.raw_lock); #endif } @@ -11626,7 +11626,7 @@ static int __init net_dev_init(void) INIT_WORK(flush, flush_backlog); - skb_queue_head_init(&sd->input_pkt_queue); + skb_queue_head_init_raw(&sd->input_pkt_queue); skb_queue_head_init(&sd->process_queue); #ifdef CONFIG_XFRM_OFFLOAD skb_queue_head_init(&sd->xfrm_backlog);