Re: [dpdk-dev] [PATCH v6 3/4] bond mode 4: allow external state machine

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-11-03 08:48, Panu Matilainen:
> On 11/02/2015 06:42 PM, Eric Kinzie wrote:
> > On Mon Nov 02 12:23:47 +0200 2015, Panu Matilainen wrote:
> >> On 11/01/2015 08:17 PM, Thomas Monjalon wrote:
> >>> 2015-10-19 08:36, Eric Kinzie:
> >>>>    Size of struct rte_eth_bond_8023ad_conf changed.  Increment LIBABIVER
> >>>>    and version bond_mode_8023ad_setup and bond_mode_8023ad_conf_get
> >>>>    functions.
> >>> [...]
> >>>> +VERSION_SYMBOL(bond_mode_8023ad_setup, _v20, 2.0);
> >>> [...]
> >>>> +BIND_DEFAULT_SYMBOL(bond_mode_8023ad_setup, _v22, 2.2);
> >>>> +MAP_STATIC_SYMBOL(void bond_mode_8023ad_setup(struct rte_eth_dev *dev, struct rte_eth_bond_8023ad_conf *conf), \
> >>>> +		  bond_mode_8023ad_setup_v22);
> >>>
> >>> I'm sorry it doesn't work well when trying to build a combined lib:
> >>>
> >>> ld: libdpdk.so: version node not found for symbol bond_mode_8023ad_setup@@DPDK_2.2
> >>>
> >>> The symbols are OK in the .o file:
> >>> 0000000000002340 g     F .text  0000000000000171 bond_mode_8023ad_setup@@DPDK_2.2
> >>> 0000000000002260 g     F .text  00000000000000da bond_mode_8023ad_setup@DPDK_2.0
> >>> 0000000000002260 g     F .text  00000000000000da bond_mode_8023ad_setup_v20
> >>> 0000000000002340 g     F .text  0000000000000171 bond_mode_8023ad_setup_v22
> >>> 0000000000000000         *UND*  0000000000000000 bond_mode_8023ad_setup
> >>>
> >>> I don't understand the problem and I am considering disabling versioning in
> >>> combined library.
> >>>
> >>> Any idea?
> >>>
> >>
> >> The .map additions look incorrect to me:
> >>
> >>> diff --git a/drivers/net/bonding/rte_eth_bond_version.map b/drivers/net/bonding/rte_eth_bond_version.map
> >>> index 22bd920..7f78717 100644
> >>> --- a/drivers/net/bonding/rte_eth_bond_version.map
> >>> +++ b/drivers/net/bonding/rte_eth_bond_version.map
> >>> @@ -17,6 +17,9 @@  DPDK_2.0 {
> >>> 	rte_eth_bond_slaves_get;
> >>> 	rte_eth_bond_xmit_policy_get;
> >>> 	rte_eth_bond_xmit_policy_set;
> >>> +	rte_eth_bond_8023ad_ext_collect;
> >>> +	rte_eth_bond_8023ad_ext_distrib;
> >>> +	rte_eth_bond_8023ad_ext_slowtx;
> >>
> >> These symbols didn't exist in DPDK 2.0 but are only being added
> >> here. So why are they being added to the 2.0 section?
> >
> > Yes, I think these should probably be moved.
> >
> >
> >>>
> >>> 	local: *;
> >>> };
> >>> @@ -27,3 +30,10 @@  DPDK_2.1 {
> >>> 	rte_eth_bond_free;
> >>>
> >>> } DPDK_2.0;
> >>> +
> >>> +DPDK_2.2 {
> >>> +	local
> >>> +
> >>> +	bond_mode_8023ad_conf_get;
> >>> +	bond_mode_8023ad_setup;
> >>> +} DPDK_2.1;
> >>
> >> These are marked local, as in, "not exported" which doesn't seem
> >> right. Also they're lacking the rte_eth_ prefix. AFAICS this is what
> >> the symbol export map should look like here:
> >
> >
> > These were not exported to begin with.  But after versioning these
> > functions, they are exported unless explicitly declared to be local here.
> >
> 
> And this does not ring any warning bells? :)
> 
> Sorry, I was not looking at the patch as a whole. You're declaring these 
> symbols as exported with the versioning macros, eg
> 
> BIND_DEFAULT_SYMBOL(bond_mode_8023ad_setup, _v22, 2.2);
> 
> ...and then explicitly telling it to not export them by declaring local, 
> and then we wonder why it has trouble finding the symbols.
> The versioning macros wont invent the librte_ prefix for you, you need 
> to rename the functions accordingly.
> 
> But all this versioning gymnastics is moot anyway because you declare 
> the ABI incompatible:
> 
> -LIBABIVER := 1
> +LIBABIVER := 2
> 
> This changes the library soname, so no binary compiled against the 
> previous version can possibly use it anymore. As in, by definition there 
> can be no callers of the _v20 variants after this ABI version bump.

Panu, thanks for your careful review.
We must remove the private functions from the export map.and not bump LIBABIVER.