[jeffbee]

There isn't really a "system malloc on Linux". Many distributions come with the GNU allocator based on ptmalloc2, but there is no particular reason that a distro could not come out of the box with any other allocator. The world's most widespread Linux distribution uses LLVM's Scudo allocator. Alpine Linux comes with musl's (unbelievably slow) allocator, although it is possible to rebuild it with mimalloc.