On Sun, 2017-05-07 at 09:33 +0300, Leon Romanovsky wrote: > On Sat, May 06, 2017 at 12:48:26PM +0200, Jiri Pirko wrote: > > Fri, May 05, 2017 at 03:17:54PM CEST, leon@xxxxxxxxxx wrote: > > >On Fri, May 05, 2017 at 08:54:57AM +0200, Jiri Benc wrote: > > >> On Thu, 4 May 2017 21:02:08 +0300, Leon Romanovsky wrote: > > >> > In order to close object model, ensure reuse of existing code and make this > > >> > tool usable from day one, we decided to implement wrappers over legacy sysfs > > >> > prior to implementing netlink functionality. As a nice bonus, it will allow > > >> > to use this tool with old kernels too. > > >> > > >> This sounds wrong. We don't support legacy ioctl interface for the 'ip' > > >> command, either. I think rdma should be converted to netlink first and > > >> the new tool should only use netlink. > > > > > >RDMA in slightly different situation than "ip" tool was. "ip" was implemented > > >when tools like ifconfig existed. It allowed to old and new systems to be > > >configured to some degree. In RDMA community, there are no similar tools like > > >"ifconfig". Implementation in netlink-only interface will leave old systems without > > >common tool at all. > > > > > >As an upstream-oriented person, I personally fine with that, but anyway would > > >like to get wider agreement/disagreement on that, before removing sysfs > > >parsing logic from the rdmatool. > > > > I tend to agree with Jiri Benc. I fear that supporting sysfs + netlink > > api later on for the same things will make the code unnecessary complex. > > Also, the legacy sysfs will most likely stay there forever so there will > > be no actual motivation to port the existing things to the new netlink > > api. > > > > For the prototyping purposes, I belive that what you did makes perfect > > sense. But for the actual mergable version, my feeling is that we need > > to strictly stick with new netlink rdma interface and just forget about > > the old sysfs one. Distros would have to backport the new kernel > > rdma netlink api. > > Thanks, > It looks like that most of the comments are in favor of netlink-only > solution. Leon, I like the thought bw comp support. After all this is a user level tool so it should be possible to make a clean implementation that makes the old stuff easy to remove at some point. It will also attract users much sooner than if they have to have their own if-then-else logic around everything to be able to support old and new. > > Yes, this will be little bit more painful at the beginning, but in the > > long run, I believe it will save some severe headaches. > > IMHO, some headache will be there anyway, just a matter of how how far out it gets. Knut -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
