Re: [dpdk-dev] [PATCH v3 01/10] table: added structure for storing table stats

["Dumitrescu, Cristian" <cristian.dumitrescu@intel.com>]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Tuesday, May 26, 2015 10:58 PM
> To: Dumitrescu, Cristian
> Cc: Gajdzica, MaciejX T; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 01/10] table: added structure for storing
> table stats
> 
> On Tue, 26 May 2015 21:40:42 +0000
> "Dumitrescu, Cristian" <cristian.dumitrescu@intel.com> wrote:
> 
> >
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen
> > > Hemminger
> > > Sent: Tuesday, May 26, 2015 3:58 PM
> > > To: Gajdzica, MaciejX T
> > > Cc: dev@dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH v3 01/10] table: added structure for
> storing
> > > table stats
> > >
> > > On Tue, 26 May 2015 14:39:38 +0200
> > > Maciej Gajdzica <maciejx.t.gajdzica@intel.com> wrote:
> > >
> > > > +
> > > >  /** Lookup table interface defining the lookup table operation */
> > > >  struct rte_table_ops {
> > > >  	rte_table_op_create f_create;       /**< Create */
> > > > @@ -194,6 +218,7 @@ struct rte_table_ops {
> > > >  	rte_table_op_entry_add f_add;       /**< Entry add */
> > > >  	rte_table_op_entry_delete f_delete; /**< Entry delete */
> > > >  	rte_table_op_lookup f_lookup;       /**< Lookup */
> > > > +	rte_table_op_stats_read f_stats;	/**< Stats */
> > > >  };
> > >
> > > Another good idea, which is an ABI change.
> >
> > This is simply adding a new API function, this is not changing any function
> prototype. There is no change required in the map file of this library. Is there
> anything we should have done and we did not do?
> >
> 
> But if I built an external set of code which had rte_table_ops (don't worry I
> haven't)
> and that binary ran with the new definition, the core code it table would
> reference
> outside the (old version) of rte_table_ops structure and find garbage.

This is just adding  a new field at the end of an API data structure. Based on input from multiple people and after reviewing the rules listed on http://dpdk.org/doc/guides/rel_notes/abi.html , I think this is an acceptable change. There are other patches in flight on this mailing list that are in the same situation. Any typical/well behaved application will not break due to this change.