On Wed, 8 Sep 2021 10:21:18 -0700 Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > Again I am ignorant on the details so if you can clarify the following > > it may help me and others to better understand the problem: > > > > 1. Peter's patch appears to just take the same "fallback" path > > that would be taken if the trylock failed. > > Is this really a breakage or just loss of performance ? > > I would expect the latter, since it is called "fallback". > > As Yonghong explained it's a user space breakage. > User space tooling expects build_id to be available 99.999% of the time > and that's what users observed in practice. > They've built a bunch of tools on top of this feature. > The data from these tools goes into various datacenter tables > and humans analyze it later. > So Peter's proposal is not acceptable. We don't want to get yelled at. > I'm not understanding. Peter said "this patch merely removes a performance tweak" and you and Yonghong said "it breaks userspace". These assertions are contradictory! Please describe the expected userspace-visible change from Peter's patch in full detail? And yes, it is far preferable that we resolve this by changing BPF to be a better interface citizen, please. Let's put those thinking caps on?
