On Fri, 23 Jun 2017 13:03:55 +0530 Hemant Agrawal <hemant.agra...@nxp.com> wrote:
> On 6/21/2017 9:58 PM, Stephen Hemminger wrote: > > Looking at some other issues, I noticed that both the TAP and MLX5 device > > drivers are looking at kernel version through uname. Although this may > > seem like a good way to deal with kernel API changes, it is not reliable. > > > > Enterprise kernel distro vendors never change kernel version but do backport > > features from later kernels. Therefore the behavior expected may change > > even though kernel version doesn't change. Also kernel version does not > > dictate that the expected feature (like flower) is in the kernel > > configuration. > > > > I recommend this be looked for in all future submissions. Maybe even flagged > > as error in DPDK version of checkpatch. > > what is the alternative than? > > There are many legitimate cases, where userspace code need to make > decision on the basis underlying kernel version. > > In some cases, user space code can add error handling and fallback, but > it is not possible in all cases. Userspace code should test for the specific feature it wants. I.e is the flow qdisc available. Then report missing feature as error if necessary.
