On Tue, 21 Apr 2015 09:34:27 +0000 "Burakov, Anatoly" <anatoly.burakov at intel.com> wrote:
> Hi Stephen, > > > The VFIO_PRESENT #define was a landmine and we hit it. > > The DPDK has a config system and it should be used rather than silently > > dropping a feature during build only to have it fail at run time. > > > > If VFIO is configured, and the kernel headers are not present the build > > should fail. Rather than leaving developers puzzling why the build system > > (with old kernel headers) produced non functioning DPDK and their system > > (with new kernel headers) produced correctly working DPDK. > > > > As a matter of policy, really no code should be looking at <linux/version.h> > > except for kernel drivers with compat files. > > In theory, I agree with you. In practice however, this change will > unconditionally break builds on pre-VFIO kernels (<3.6). If someone is building with an older kernel, then they should change the config. > This may be OK now, but wasn't OK at the time it was developed because > pre-VFIO kernels were still very much prevalent. AFAIK, VFIO is enabled by > default, so maybe we should disable it in the default configs? But failing at runtime is much worse.
