The new allocator uses a segregated best-fit algorithm with exact-size
lists for all sizes between 8 bytes (the minimum) and 60 bytes, one list
for blocks of size 64-252 and one for larger blocks.
Arenas managed by this allocator have built-in statistics that track
used and free memory (accounting for block headers), peak memory, and
various allocation results.
In addition, the allocator has self-checks in the form of integrity
verifications, that can be enabled with -DGINT_KMALLOC_DEBUG=1 at
configuration time or with the :dev configuration for GiteaPC. This is
used by gintctl.
The kmalloc interface is extended with a new arena covering all unused
memory in user RAM, managed by gint's allocator. It spans about 4 kB on
SH3 fx-9860G, 16 kB on SH4 fx-9860G, and 500 kB on fx-CG 50, in addition
to the OS heap. This new arena is now the default arena for malloc(),
except on SH3 where some heap problems are currently known.
