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| author | Tom Herbert <therbert@google.com> | 2010-05-20 18:37:59 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-05-21 00:38:33 -0700 |
| commit | 76cc8b13a6e41b537fd262b600da1571314add62 (patch) | |
| tree | a8a25a4f23be5c0eeed77dd9fcb30dc9b315e519 /include/linux/netdevice.h | |
| parent | 1f01bfd202bc539bccd282befa2bbdb8d6ad80ee (diff) | |
| download | lwn-76cc8b13a6e41b537fd262b600da1571314add62.tar.gz lwn-76cc8b13a6e41b537fd262b600da1571314add62.zip | |
net: fix problem in dequeuing from input_pkt_queue
Fix some issues introduced in batch skb dequeuing for input_pkt_queue.
The primary issue it that the queue head must be incremented only
after a packet has been processed, that is only after
__netif_receive_skb has been called. This is needed for the mechanism
to prevent OOO packet in RFS. Also when flushing the input_pkt_queue
and process_queue, the process queue should be done first to prevent
OOO packets.
Because the input_pkt_queue has been effectively split into two queues,
the calculation of the tail ptr is no longer correct. The correct value
would be head+input_pkt_queue->len+process_queue->len. To avoid
this calculation we added an explict input_queue_tail in softnet_data.
The tail value is simply incremented when queuing to input_pkt_queue.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index a1bff6518166..256419583d9d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1407,17 +1407,25 @@ struct softnet_data { struct softnet_data *rps_ipi_next; unsigned int cpu; unsigned int input_queue_head; + unsigned int input_queue_tail; #endif unsigned dropped; struct sk_buff_head input_pkt_queue; struct napi_struct backlog; }; -static inline void input_queue_head_add(struct softnet_data *sd, - unsigned int len) +static inline void input_queue_head_incr(struct softnet_data *sd) { #ifdef CONFIG_RPS - sd->input_queue_head += len; + sd->input_queue_head++; +#endif +} + +static inline void input_queue_tail_incr_save(struct softnet_data *sd, + unsigned int *qtail) +{ +#ifdef CONFIG_RPS + *qtail = ++sd->input_queue_tail; #endif } |