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| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-07-07 22:59:14 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-07-10 22:18:46 -0700 |
| commit | 1722933323b70f44b0548131604f1f3454c2aa8f (patch) | |
| tree | b0abfaae2f0b3f5c2a13de3fbd629c3331193c17 /Documentation/networking | |
| parent | 963bd949b12158d9b5380b718b31c4b33372ed73 (diff) | |
| download | linux-1722933323b70f44b0548131604f1f3454c2aa8f.tar.gz | |
[NET]: netdevice locking assumptions documentation
Update the documentation about locking assumptions. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/netdevices.txt | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/Documentation/networking/netdevices.txt b/Documentation/networking/netdevices.txt index ce1361f95243..a6cab674b676 100644 --- a/Documentation/networking/netdevices.txt +++ b/Documentation/networking/netdevices.txt @@ -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. |