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authorDaniel Borkmann <dborkman@redhat.com>2014-04-02 20:52:57 +0200
committerDavid S. Miller <davem@davemloft.net>2014-04-03 14:29:12 -0400
commit8e2f1a63f2217365223026422a2f8ba5967051d6 (patch)
tree617c58bd5a55d41cfe3c28e1087a17691f1ae197
parent0f97ede45e65ffb6eab856313e79b14b902bcfaa (diff)
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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.h24
-rw-r--r--net/packet/af_packet.c2
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);