malloc: Move mmap code out of __libc_free hotpath

Currently __libc_free checks for a freed mmap chunk in the fast path.
Also errno is always saved and restored to preserve it.  Since mmap chunks
are larger than the largest tcache chunk, it is safe to delay this and
handle tcache, smallbin and medium bin blocks first.  Move saving of errno
to cases that actually need it.  Remove a safety check that fails on mmap
chunks and a check that mmap chunks cannot be added to tcache.

Performance of bench-malloc-thread improves by 9.2% for 1 thread and
6.9% for 32 threads on Neoverse V2.

Reviewed-by: DJ Delorie  <dj@redhat.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

0 files changed, 0 insertions, 0 deletions