On 11/11/20 8:06 AM, Daniel Borkmann wrote: > > Not really. What you imply here is that we're living in a perfect world > and that > all distros follow suite and i) add libbpf dependency to their official > iproute2 > package, ii) upgrade iproute2 package along with new kernel releases and > iii) > upgrade libbpf along with it so that users are able to develop BPF > programs against > the feature set that the kernel offers (as intended). These are a lot of > moving parts > to get right, and as I pointed out earlier in the conversation, it took > major distros > 2 years to get their act together to officially include bpftool as a > package - Yes, there are lot of moving parts and that puts a huge burden on distributions. The trend that related s/w is outdated 2-3 months after a release can be taken as a sign that bpf is not stable and ready for distributions to take on and support. bpftool is only 3 years old (Oct 2017 is first kernel commit). You can not expect distributions to chase every whim from kernel developers, so bpftool needed to evolve and prove its usefulness. It has now, so really the disappointment should be limited to distributions over the past 12 months, especially Ubuntu 20.04 (most recent LTS) not having a libbpf and bpftool releases. But again, 20.04 was too old for BTF 3 months after it was released and that comes back to the bigger question of whether bpf is really ready for distributions to support. More below. Focusing on the future: for Ubuntu (and Debian?) bpftool is in the linux-tools-common package. perf has already trained distributions to release a tools package with kernel releases. That means bpftool updates follow the kernel cadence. bpftool requires libbpf and I believe given the feature dependencies will force libbpf versions to follow kernel releases, so I believe your goal is going to be achieved by those dependencies. But there is an on-going nagging problem which needs to be acknowledged and solved. As an *example*, Ubunutu has kernel updates to get new hardware support (HWE releases). Updating kernels on an LTS is problematic when the kernel update requires toolchain updates to maintain features (DEBUG_INFO_BTF) and library updates to get tools for that kernel version working. That is a huge disruption to their customers who want stability — the whole reason for LTS distributions.
