diff options
| author | Daniel Borkmann <dborkman@redhat.com> | 2014-04-02 20:52:57 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-04-03 14:29:12 -0400 |
| commit | 8e2f1a63f2217365223026422a2f8ba5967051d6 (patch) | |
| tree | 617c58bd5a55d41cfe3c28e1087a17691f1ae197 | |
| parent | 0f97ede45e65ffb6eab856313e79b14b902bcfaa (diff) | |
| download | blackbird-obmc-linux-8e2f1a63f2217365223026422a2f8ba5967051d6.tar.gz blackbird-obmc-linux-8e2f1a63f2217365223026422a2f8ba5967051d6.zip | |
packet: fix packet_direct_xmit for BQL enabled drivers
Currently, in packet_direct_xmit() we test the assigned netdevice queue
for netif_xmit_frozen_or_stopped() before doing an ndo_start_xmit().
This can have the side-effect that BQL enabled drivers which make use
of netdev_tx_sent_queue() internally, set __QUEUE_STATE_STACK_XOFF from
within the stack and would not fully fill the device's TX ring from
packet sockets with PACKET_QDISC_BYPASS enabled.
Instead, use a test without BQL bit so that bursts can be absorbed
into the NICs TX ring. Fix and code suggested by Eric Dumazet, thanks!
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/linux/netdevice.h | 24 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 2 |
2 files changed, 20 insertions, 6 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 775cc956ff78..7ed3a3aa6604 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -519,11 +519,18 @@ enum netdev_queue_state_t { __QUEUE_STATE_DRV_XOFF, __QUEUE_STATE_STACK_XOFF, __QUEUE_STATE_FROZEN, -#define QUEUE_STATE_ANY_XOFF ((1 << __QUEUE_STATE_DRV_XOFF) | \ - (1 << __QUEUE_STATE_STACK_XOFF)) -#define QUEUE_STATE_ANY_XOFF_OR_FROZEN (QUEUE_STATE_ANY_XOFF | \ - (1 << __QUEUE_STATE_FROZEN)) }; + +#define QUEUE_STATE_DRV_XOFF (1 << __QUEUE_STATE_DRV_XOFF) +#define QUEUE_STATE_STACK_XOFF (1 << __QUEUE_STATE_STACK_XOFF) +#define QUEUE_STATE_FROZEN (1 << __QUEUE_STATE_FROZEN) + +#define QUEUE_STATE_ANY_XOFF (QUEUE_STATE_DRV_XOFF | QUEUE_STATE_STACK_XOFF) +#define QUEUE_STATE_ANY_XOFF_OR_FROZEN (QUEUE_STATE_ANY_XOFF | \ + QUEUE_STATE_FROZEN) +#define QUEUE_STATE_DRV_XOFF_OR_FROZEN (QUEUE_STATE_DRV_XOFF | \ + QUEUE_STATE_FROZEN) + /* * __QUEUE_STATE_DRV_XOFF is used by drivers to stop the transmit queue. The * netif_tx_* functions below are used to manipulate this flag. The @@ -2252,11 +2259,18 @@ static inline bool netif_xmit_stopped(const struct netdev_queue *dev_queue) return dev_queue->state & QUEUE_STATE_ANY_XOFF; } -static inline bool netif_xmit_frozen_or_stopped(const struct netdev_queue *dev_queue) +static inline bool +netif_xmit_frozen_or_stopped(const struct netdev_queue *dev_queue) { return dev_queue->state & QUEUE_STATE_ANY_XOFF_OR_FROZEN; } +static inline bool +netif_xmit_frozen_or_drv_stopped(const struct netdev_queue *dev_queue) +{ + return dev_queue->state & QUEUE_STATE_DRV_XOFF_OR_FROZEN; +} + static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue, unsigned int bytes) { diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index c81a9719b5b2..72e0c71fb01d 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -261,7 +261,7 @@ static int packet_direct_xmit(struct sk_buff *skb) local_bh_disable(); HARD_TX_LOCK(dev, txq, smp_processor_id()); - if (!netif_xmit_frozen_or_stopped(txq)) { + if (!netif_xmit_frozen_or_drv_stopped(txq)) { ret = ops->ndo_start_xmit(skb, dev); if (ret == NETDEV_TX_OK) txq_trans_update(txq); |
