[NET]: netdevice locking assumptions documentation (17229333) · Commits · 戴 / test

Documentation/networking/netdevices.txt

+8 −7

Original line number	Diff line number	Diff line
		@@ -20,7 +20,6 @@ private data which gets freed when the network device is freed. If
		separately allocated data is attached to the network device
		(dev->priv) then it is up to the module exit handler to free that.


		struct net_device synchronization rules
		=======================================
		dev->open:
		@@ -43,16 +42,17 @@ dev->get_stats:

		dev->hard_start_xmit:
		Synchronization: netif_tx_lock spinlock.

		When the driver sets NETIF_F_LLTX in dev->features this will be
		called without holding netif_tx_lock. In this case the driver
		has to lock by itself when needed. It is recommended to use a try lock
		for this and return -1 when the spin lock fails.
		for this and return NETDEV_TX_LOCKED when the spin lock fails.
		The locking there should also properly protect against
		set_multicast_list
		Context: Process with BHs disabled or BH (timer).
		Notes: netif_queue_stopped() is guaranteed false
		Interrupts must be enabled when calling hard_start_xmit.
		(Interrupts must also be enabled when enabling the BH handler.)
		set_multicast_list.

		Context: Process with BHs disabled or BH (timer),
		will be called with interrupts disabled by netconsole.

		Return codes:
		o NETDEV_TX_OK everything ok.
		o NETDEV_TX_BUSY Cannot transmit packet, try later
		@@ -74,4 +74,5 @@ dev->poll:
		Synchronization: __LINK_STATE_RX_SCHED bit in dev->state. See
		dev_close code and comments in net/core/dev.c for more info.
		Context: softirq
		will be called with interrupts disabled by netconsole.