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>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 775cc95..7ed3a3a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -519,11 +519,18 @@
__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 @@
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)
{
