[musl] musl and jemalloc support

["Kaisrlík, Jan" <jan.kaisrlik@avast.com>]

Hello guys,

I would like to ask about the support of external malloc and jemalloc.
I find an old mail in ML claiming that support is not there and using
external malloc function can potentially cause problems[1] and a
thread[2] on jemalloc saying the same. On the other hand, I find a lot
of pages comparing speed like pages [3] and also I noticed that Musl
claims "replacement of malloc is now allowed/supported" statement in
changelog [4]. So, my expectation is Musl from version 1.1.20 supports
the loading of external malloc function and it is working. Is my
assumption correct? Does it have any limitations, e.g., it has to be
done in compilation time, is LD_PRELOAD supported?

The reason why I'm asking is that some apps started crashing with a
weird coredump from the moment I used
LD_PRELOAD=/usr/lib/libjemalloc.so.2:/usr/lib/libpthread.so.

Thank you for your answer.

The best,
Jan

[1]: https://www.openwall.com/lists/musl/2014/08/08/11
[2]: https://github.com/jemalloc/jemalloc/issues/1443
[3]: https://users.rust-lang.org/t/optimizing-rust-binaries-observation-of-musl-versus-glibc-and-jemalloc-versus-system-alloc/8499/7
[4]: https://git.musl-libc.org/cgit/musl/tree/WHATSNEW#n1916