On 1/10/2014 12:18 AM, Jason Wang wrote: > Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The > will cause several issues: > > - NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan > instead of lower device which misses the necessary txq synchronization for > lower device such as txq stopping or frozen required by dev watchdog or > control path. > - dev_hard_start_xmit() was called with NULL txq which bypasses the net device > watchdog. > - dev_hard_start_xmit() does not check txq everywhere which will lead a crash > when tso is disabled for lower device. > > Fix this by explicitly introducing a new param for .ndo_select_queue() for > just > selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was > also > extended to accept this parameter and dev_queue_xmit_accel() was used to do l2 > forwarding transmission. > > With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no > need > to check txq against NULL in dev_hard_start_xmit(). Also there's no need to > keep > a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of > dev_queue_xmit() to do the transmission. > > In the future, it was also required for macvtap l2 forwarding support since it > provides a necessary synchronization method. > > Cc: John Fastabend <[email protected]> > Cc: Neil Horman <[email protected]> > Cc: [email protected] > Signed-off-by: Jason Wang <[email protected]> > > --- > Changes from V2: > - Reuse dev_queue_xmit() instead of re-inventing dfwd_direct_xmit() > - remove the unnecessary braces > Changes from V1: > - Adding a new parameter to ndo_select_queue instead of a new method to select > queue for l2 forwarding. > - Remove the unnecessary ndo_dfwd_start_xmit() since txq was selected > explicitly. > - Keep NETIF_F_LLTX when netdev feature is changed. > - Shape the commit log > ---
Looks good to me thanks, I tested my macvlan use cases and everything works as expected. Acked-by: John Fastabend <[email protected]> ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ E1000-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
