Re: [ethtool PATCH 4/4] v5 Add RX packet classification interface

[Ben Hutchings <bhutchings@solarflare.com>]

On Wed, 2011-05-04 at 10:09 -0700, Dimitris Michailidis wrote:
> On 05/03/2011 04:34 PM, Ben Hutchings wrote:
> > On Tue, 2011-05-03 at 16:23 -0700, Dimitris Michailidis wrote:
> >> I think RX_CLS_LOC_UNSPEC should be passed to the driver, where there is 
> >> enough knowledge to pick an appropriate slot.  So I'd remove the
> >>
> >>      if (loc == RX_CLS_LOC_UNSPEC)
> >>
> >> block above, let the driver pick a slot, and then pass the selected location 
> >> back for ethtool to report.
> > 
> > But first we have to specify this in the ethtool API.  So please propose
> > a patch to ethtool.h.
> 
> In the past we discussed that being able to specify the first available slot or 
> the last available would be useful, so something like the below?
>
> diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
> index 4194a20..909ef79 100644
> --- a/include/linux/ethtool.h
> +++ b/include/linux/ethtool.h
> @@ -442,7 +442,8 @@ struct ethtool_flow_ext {
>    *	includes the %FLOW_EXT flag.
>    * @ring_cookie: RX ring/queue index to deliver to, or %RX_CLS_FLOW_DISC
>    *	if packets should be discarded
> - * @location: Index of filter in hardware table
> + * @location: Index of filter in hardware table, or %RX_CLS_FLOW_FIRST_LOC for
> + *	first available index, or %RX_CLS_FLOW_LAST_LOC for last available
[...]

I think that's reasonable.  We should also explicitly state that
location determines priority, i.e. if a packet matches two filters then
the one with the lower location wins.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.