netpoll: Respect NETIF_F_LLTX
Stop taking the transmit lock when a network device has specified
NETIF_F_LLTX.
If no locks needed to trasnmit a packet this is the ideal scenario for
netpoll as all packets can be trasnmitted immediately.
Even if some locks are needed in ndo_start_xmit skipping any unnecessary
serialization is desirable for netpoll as it makes it more likely a
debugging packet may be trasnmitted immediately instead of being
deferred until later.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0d8c871..4cd5e9e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2909,6 +2909,11 @@
} \
}
+#define HARD_TX_TRYLOCK(dev, txq) \
+ (((dev->features & NETIF_F_LLTX) == 0) ? \
+ __netif_tx_trylock(txq) : \
+ true )
+
#define HARD_TX_UNLOCK(dev, txq) { \
if ((dev->features & NETIF_F_LLTX) == 0) { \
__netif_tx_unlock(txq); \
