https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64128
--- Comment #4 from Eelis <gcc-bugzilla at contacts dot eelis.net> --- Yeah, I noticed that tcmalloc is also way faster, and since tcmalloc barely over-allocates for the sizes requested by vector, there is no benefit to using malloc_usable_size (which it also supports) there. So I think the bottom line is indeed: just don't use glibc malloc, because it's very slow.
