2015-02-16 12:01, Panu Matilainen: > On 02/13/2015 03:18 PM, Thomas Monjalon wrote: > > 2015-02-13 12:33, Panu Matilainen: > >> On 02/13/2015 11:28 AM, Thomas Monjalon wrote: > >>> 2015-02-13 09:27, Panu Matilainen: > >>>> On 02/12/2015 05:44 PM, Thomas Monjalon wrote: > >>>>> A library is considered as a plugin if there is no public API and it > >>>>> registers itself. That's the case of normal PMD. > >>>>> But bonding and Xen have some library parts with public API. > >>>>> It has been discussed and agreed for bonding but I'm not aware of the > >>>>> Xen case. > >>>> > >>>> Fair enough, thanks for the explanation. > >>>> > >>>> Just wondering about versioning of these things - currently all the PMDs > >>>> are versioned as well, which is slightly at odds with their expected > >>>> usage, dlopen()'ed items usually are not versioned because it makes the > >>>> files moving targets. But if a plugin can be an library too then it > >>>> clearly needs to be versioned as well. > >>> > >>> Not sure to understand your considerations. > >>> Plugins must be versioned because there can be some incompatibilities > >>> like mbuf rework. > >> > >> Plugins are version-dependent obviously, but the issue is somewhat > >> different from library versioning. Plugins are generally consumers of > >> the versioned ABIs, whereas libraries are the providers. > >> > >>>> I'm just thinking of typical packaging where the unversioned *.so > >>>> symlinks are in a -devel subpackage and the versioned libraries are in > >>>> the main runtime package. Plugins should be loadable by a stable > >>>> unversioned name always, for libraries the linker handles it behind the > >>>> scenes. So in packaging these things, plugin *.so links need to be > >>>> handled differently (placed into the main package) from others. Not > >>>> rocket science to filter by 'pmd' in the name, but a new twist anyway > >>>> and easy to get wrong. > >>>> > >>>> One possibility to make it all more obvious might be having a separate > >>>> directory for plugins, the mixed case ccould be handled by symlinks. > >>> > >>> I think I don't understand which use case you are trying to solve. > >> > >> Its a usability/documentation issue more than a technical one. If plugin > >> DSO's are versioned (like they currently are), then loading them via eg > >> -d becomes cumbersome since you need to hunt down and provide the > >> versioned name, eg "testpmd -d librte_pmd_pcap.so.1 [...]" > >> > >> Like said above, it can be worked around by leaving the unversioned > >> symlinks in place for plugins in runtime (library) packages, but that > >> sort of voids the point of versioning. One possibility would be > >> introducing a per-version plugin directory that would be used as the > >> default path for dlopen() unless an absolute path is used. > > > > It makes me think that instead of using a -d option per plugin, why not > > adding a -D option to load all plugins from a directory? > > Are you thinking of "-D <plugindir>" or just -D (to use a build-time > hardwired directory)?
I'm thinking of "-D <plugindir>". I understand you would like a "hardwired" default directory which would be properly packaged by a distribution. Maybe that it could be a build-time default to load all the plugins of a directory (without option). Then the -d and -D options would overwrite the build-time default behaviour.