[ovs-dev] [PATCH 4/6] internal-vport: Convert internal devices to vport stats.

[Ben Pfaff]

Before I get started, while reviewing code I noticed that vport.c has
some "extern" declarations in it.  Those are a no-no in the kernel that
I see people getting called out on from time to time (mostly by Andrew
Morton).  We should move them into a header.

On Wed, Jun 09, 2010 at 07:33:19PM -0700, Jesse Gross wrote:
> Internal devices currently keep track of stats themselves.  However,
> we now have stats tracking in the vport layer, so convert to use
> that instead to avoid code duplication and take advantage of
> additional features such as 64-bit counters.

At first I thought there must be recursion in internal_dev_get_stats(),
but I convinced myself it's OK:

  vport_user_stats_get() calls
    vport_get_stats(), which implements generic stats itself.

  something in the core kernel network stack calls
    internal_dev_get_stats(), which calls
      vport_get_stats(), which implements generic stats itself.

It's too bad both network devices and vports have a member called
'get_stats'.  That's probably the source of my confusion.  Maybe we
should have added a 'v_' or 'vp_' prefix to struct vport_ops member
names.