But I think you can tweak musl to perform well, and musl is closer to the spec than glibc so I would rather use it; even if its slower in the default case for multithreaded programmes.
You can not, its allocator does thread safety via a big lock and that’s that.
> musl is closer to the spec than glibc
Is it?
> even if its slower in the default case for multithreaded programmes.
That’s far from the only situation where it’s slower though.
Swapping out jemalloc for the system allocator will net you huge performance wins if you link against musl, but you’ll still have issues with multithreading performance due to the slower implementations of necessary helpers.