[ovs-dev] [PATCH] ofproto-dpif-xlate: Work around Linux netdev_max_backlog limit.

[Flavio Leitner]

On Tue, Sep 09, 2014 at 03:07:28PM -0700, Ben Pfaff wrote:
> Linux has an internal queue that temporarily holds packets transmitted to
> certain network devices.  If too many packets are transmitted to such
> network devices within a single list of actions, then packets tend to get
> dropped.  Broadcast or flooded or multicast packets on bridges with
> thousands of ports are examples of how this can occur.
> 
> This commit avoids the problem by implementing a flow in userspace when it
> outputs its packet more times than the maximum length of the queue.
> 
> CC: Flavio Leitner <fbl at redhat.com>
> Signed-off-by: Ben Pfaff <blp at nicira.com>
> ---

Hi Ben,

The code looks good to me.

I used netdev_max_backlog  = 110 here and I was able to go all
the 4k ports in the test.  Without the patch, the failure starts
with 112 ports.

Thanks!

Acked-by: Flavio Leitner <fbl at redhat.com>