[ovs-dev] [PATCH 1/3] ovs-dpctl: Show number of flows

[Jesse Gross]

On Wed, Aug 3, 2011 at 10:19 AM, Simon Horman <horms at verge.net.au> wrote:
> Expose the number of flows present in a datapath to user-space
> and to users via ovs-dpctl show.
>
> e.g.:
>
> ovs-dpctl show br3
> system at br3:
>        lookups: frags:0, hit:0, missed:0, lost:0
>        flows: 0
>        ...
>
> Signed-off-by: Simon Horman <horms at verge.net.au>
>
> ---
>
> This has proved quite useful while looking at ways
> to increase the number of flows that can be handled.
> I am unsure if it is generally useful or not to
> warrant inclusion upstream.

I think this is generally useful information.  We actually used to
report it but it was eliminated during the transition to Netlink
because it was no longer strictly necessary (it was previously used to
size buffers) and because it was grouped together with some other
information that exposed too much in the way of implementation
details.

I think the place to put it is back where it originally was, which is
in struct odp_stats.  Stil we (still) haven't locked down the
interface yet, it's OK to change the structure.  My main goal in the
process of locking down the userspace/kernel interface is to reduce
the size and this generally simplifies things anyways.