[[LSF/MM/BPF TOPIC] Progress on BTF linking and deduplication using the toolchain

[Nick Alcock <nick.alcock@oracle.com>]

This talk will provide an update on the work we have done in binutils and
pahole to support BTF.

We have been working on pahole modifications, intended for use with
GCC-generated BTF information, providing a more direct handling of BTF
without the need for DWARF to BTF conversion.

This is done using libctf from binutils, which as of our latest version (not
yet on binutils master), can read and write BTF in a way that is fully
compatible with the existing mechanism.  We also have added support for
merging and deduplicating BTF in the linker.  In addition we can now dump
BTF with objdump.

We will show comparisons between the old and new approach within pahole,
which will exemplify differences in speed, as well as the lack of
differences in output.

This talk will give a brief overview of how this works as well as a short
demonstration.


(Like several others, I'm hoping I can do this remotely: transport from
the UK across Bank Holiday Monday is something between awful and
abominable.

I've added a couple of other possible attendees -- Cc:ed -- to the
Google form side of this: if this was overstepping some sort of bound,
since I'm not a subsystem maintainer of any sort, my apologies.)