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BTF examples or documentation?

PJ Waskiewicz
 

Hi folks,

We (Maciek and I) were on the call today, and were experiencing some audio/mic issues. We're looking for any documentation or usage models that people might have in flight already for BTF. Outside of the kernel source, we are drawing a blank. Any pointers here would be most helpful.

Thanks,
-PJ

Brendan Gregg
 

On Wed, Aug 8, 2018 at 1:28 PM, PJ Waskiewicz
<peter.waskiewicz.jr@...> wrote:
Hi folks,

We (Maciek and I) were on the call today, and were experiencing some audio/mic issues. We're looking for any documentation or usage models that people might have in flight already for BTF. Outside of the kernel source, we are drawing a blank. Any pointers here would be most helpful.
I expect to use BTF as a source for kernel struct information, as a
lightweight version of debuginfo (and hopefully one day BTF info will
be included in the kernel binary, so it's always there). I have no
docs to share yet. If you figure anything out, please share anywhere.
Here, blog post, talk, etc. :-)

Brendan

Thanks,
-PJ



Daniel Borkmann
 

On 08/08/2018 10:57 PM, Brendan Gregg wrote:
On Wed, Aug 8, 2018 at 1:28 PM, PJ Waskiewicz
<peter.waskiewicz.jr@...> wrote:
Hi folks,

We (Maciek and I) were on the call today, and were experiencing some audio/mic issues. We're looking for any documentation or usage models that people might have in flight already for BTF. Outside of the kernel source, we are drawing a blank. Any pointers here would be most helpful.
I expect to use BTF as a source for kernel struct information, as a
lightweight version of debuginfo (and hopefully one day BTF info will
be included in the kernel binary, so it's always there). I have no
docs to share yet. If you figure anything out, please share anywhere.
Here, blog post, talk, etc. :-)
There are some initial bits on BTF (mostly on the workflow for now) in
the Cilium doc that can be found here:

- http://cilium.readthedocs.io/en/latest/bpf/#llvm
- http://cilium.readthedocs.io/en/latest/bpf/#bpftool

Perhaps that helps to get started.

Cheers,
Daniel

Yonghong Song
 

On Wed, Aug 8, 2018 at 2:16 PM, Daniel Borkmann <daniel@...> wrote:
On 08/08/2018 10:57 PM, Brendan Gregg wrote:
On Wed, Aug 8, 2018 at 1:28 PM, PJ Waskiewicz
<peter.waskiewicz.jr@...> wrote:
Hi folks,

We (Maciek and I) were on the call today, and were experiencing some audio/mic issues. We're looking for any documentation or usage models that people might have in flight already for BTF. Outside of the kernel source, we are drawing a blank. Any pointers here would be most helpful.
I expect to use BTF as a source for kernel struct information, as a
lightweight version of debuginfo (and hopefully one day BTF info will
be included in the kernel binary, so it's always there). I have no
docs to share yet. If you figure anything out, please share anywhere.
Here, blog post, talk, etc. :-)
Currently, we are still in the design and prototyping stage. Will
definitely share for comments
once we got some concept design and RFC implementation.


There are some initial bits on BTF (mostly on the workflow for now) in
the Cilium doc that can be found here:

- http://cilium.readthedocs.io/en/latest/bpf/#llvm
- http://cilium.readthedocs.io/en/latest/bpf/#bpftool

Perhaps that helps to get started.

Cheers,
Daniel


Jesper Dangaard Brouer
 

On Wed, 8 Aug 2018 20:28:09 +0000
"PJ Waskiewicz" <peter.waskiewicz.jr@...> wrote:
Hi folks,

We (Maciek and I) were on the call today, and were experiencing some
audio/mic issues. We're looking for any documentation or usage
models that people might have in flight already for BTF. Outside of
the kernel source, we are drawing a blank. Any pointers here would
be most helpful.
I noticed that Arnaldo is playing with pahole (see twitter[1]) and
converting dwarf into BTF (BPF Type Format), and have written a very
nice step-by-step guide in README.btf file[2].

[1] https://twitter.com/acmel/status/1029833148006363137
[2] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/tree/README.btf

Hope this will get you a few steps further...
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer