[Bug 1894407] Re: linux-tools: can perf be linked against libbfd, maybe statically?

I too would very much like to see this fixed. As it stands `perf report`
is unusable on large binaries on Ubuntu.

Seth, I think Jay's arguments are compelling. Do you agree? If I
prepared a patch, would that be helpful?

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Title:
linux-tools: can perf be linked against libbfd, maybe statically?

Status in linux package in Ubuntu:
Won't Fix

Bug description:
The perf tool has an optional dependency on libbfd. Per Debian policy,
and due to some situation involving parallel installations of this
library, no packages should link dynamically against libbfd. In the
past, bugs have been filed to link perf statically against libbfd in
bug 783660 (from 2011) and then to just not link against it at all in
bug 1748922 (from 2018) and bug 1828234 (from 2019). The argument was
made that perf does not need this dependency, as perf can use
libiberty as an alternative to demangle C++ names.

However, that is not the only thing perf is using libbfd for: the
other is to implement an inlined version of addr2line. This was part
of an important patchset from 2013 that strove to improve the
performance of perf. In my case, I ran my program for all of 30
seconds, generating a 163M large trace, and have been waiting almost
an hour for the events to process... and it is only a third of the way
done; what I see it doing is spawning, over and over and over again,
addr2line, which it wouldn't do if linked against libbfd.

https://lore.kernel.org/patchwork/patch/413455/

Is it possible to link perf statically against libbfd, in order to let
it use the in-process implementation of addr2line? That is the
solution that I've understood for other packages, such as oprofile in
bug 426614 and bug 588033. Doing a quick grep of the code of perf for
HAVE_LIBBFD_SUPPORT, it seems like bpf disassembly support is also
dependent on libbfd (and so while it is great that Ubuntu's build of
perf has been compiled against libbpf, it seems like that
functionality is being hampered by the lack of linking libbfd).

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