Re: [RFT] Testing 1.22

[Jiri Olsa <jolsa@redhat.com>]

On Thu, May 27, 2021 at 01:41:13PM -0700, Andrii Nakryiko wrote:
> On Thu, May 27, 2021 at 12:57 PM Arnaldo <arnaldo.melo@gmail.com> wrote:
> >
> >
> >
> > On May 27, 2021 4:14:17 PM GMT-03:00, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> > >On Thu, May 27, 2021 at 12:06 PM Arnaldo <arnaldo.melo@gmail.com>
> > >wrote:
> > >>
> > >>
> > >>
> > >> On May 27, 2021 1:54:40 PM GMT-03:00, Andrii Nakryiko
> > ><andrii.nakryiko@gmail.com> wrote:
> > >> >On Thu, May 27, 2021 at 8:20 AM Arnaldo Carvalho de Melo
> > >> ><acme@kernel.org> wrote:
> > >> >>
> > >> >> Hi guys,
> > >> >>
> > >> >>         Its important to have 1.22 out of the door ASAP, so please
> > >> >clone
> > >> >> what is in tmp.master and report your results.
> > >> >>
> > >> >
> > >> >Hey Arnaldo,
> > >> >
> > >> >If we are going to make pahole 1.22 a new mandatory minimal version
> > >of
> > >> >pahole, I think we should take a little bit of time and fix another
> > >> >problematic issue and clean up Kbuild significantly.
> > >> >
> > >> >We discussed this before, it would be great to have an ability to
> > >dump
> > >> >generated BTF into a separate file instead of modifying vmlinux
> > >image
> > >> >in place. I'd say let's try to push for [0] to land as a temporary
> > >> >work around to buy us a bit of time to implement this feature. Then,
> > >> >when pahole 1.22 is released and packaged into major distros, we can
> > >> >follow up in kernel with Kbuild clean ups and making pahole 1.22
> > >> >mandatory.
> > >> >
> > >> >What do you think? If anyone agrees, please consider chiming in on
> > >the
> > >> >above thread ([0]).
> > >>
> > >> There's multiple fixes that affects lots of stakeholders, so I'm more
> > >inclined to release 1.22 sooner rather than later.
> > >>
> > >> If anyone has cycles right now to work on that detached BTF feature,
> > >releasing 1.23 as soon as that feature is complete and tested shouldn't
> > >be a problem.
> > >>
> > >> Then 1.23 the mandatory minimal version.
> > >>
> > >> Wdyt?
> > >
> > >If we make 1.22 mandatory there will be no good reason to make 1.23
> > >mandatory again. So I will have absolutely no inclination to work on
> > >this, for example. So we are just wasting a chance to clean up the
> > >Kbuild story w.r.t. pahole. And we are talking about just a few days
> > >at most, while we do have a reasonable work around on the kernel side.
> >
> > So there were patches for stop using objcopy, which we thought could uncover some can of worms, were there patches for the detached BTF  file?
> 
> No, there weren't, if I remember correctly. What's the concern,
> though? That detached BTF file isn't even an ELF, so it's
> btf__get_raw_data() and write it to the file. Done.

heya,
I probably overlooked this, but are there more details about that
detached BTF file feature somewhere? 

thanks,
jirka