23/07/2019 20:29, Stephen Hemminger: > On Tue, 23 Jul 2019 09:59:04 +0200 > Thomas Monjalon <tho...@monjalon.net> wrote: > > > 22/07/2019 20:34, Stephen Hemminger: > > > On Mon, 22 Jul 2019 19:31:08 +0200 > > > Thomas Monjalon <tho...@monjalon.net> wrote: > > > > > > > 22/07/2019 19:13, Stephen Hemminger: > > > > > Thomas Monjalon <tho...@monjalon.net> wrote: > > > > > > Are the constructors run on dlopen of the bus driver? > > > > > > > > > > Yes, constructors are run on dlopen. > > > > > But application should not have to ask DPDK to dlopen the bus devices. > > > > > > > > > > The core principle is that dynamic build of DPDK should act the same > > > > > as old > > > > > statically linked DPDK. Otherwise, the user experience is even worse, > > > > > and all > > > > > the example documentation is wrong. > > > > > > > > OK, this is where I wanted to bring the discussion. > > > > You are arguing against a design which is in DPDK from some early days. > > > > So this is an interesting discussion to have. > > > > Do we want to change the "plugin model" we have? > > > > Or do we want to simply drop this model (dlopen calls) > > > > and replace it with strong dynamic linking? > > > > > > I argue that examples should work the same with dynamic linking. > > > This used to work before the break out of the bus model, so it is a bug. > > > > The PCI support was part of EAL, yes, but the device drivers > > were plugins and already required the -d option. > > > > > For distributions, this also matters. Linking with -ldpdk which is a > > > linker > > > script should work. > > > > There is no longer this linker script with meson. > > Ok, for usability that is a problem. > Requiring user to figure out which DPDK libraries to link with is a serious > waste of time. It should be possible to just link with -ldpdk and > distribution packages and just get the necessary libraries for the application > (no extra rte_foo_bar .so loaded at run time), and the application should > just work. > > The idea that the user should link with 20 shared libraries, in the right > order and pass -d flags to eal_init to load the right PMD is user hostile. > It only makes sense if you want to invent yet another layer to manage the > ugly stuff hidden underneath. Think virt-manager versus raw KVM/QEMU. > > I know it is hard, and I know not all this will make it into 19.08 > but let's try and do better. The DPDK already has a reputation as being > like a super car, (ie unreliable and hard to drive). It doesn't have to be > that way.
About the build-time link, it is already improved thanks to the pkgconfig file generated by meson. The only issue I understand is the runtime need for -d, which is a feature, and could be removed.
