when choosing children to promote, use a sliding range to capture as many tombstones as possible.  also, experimented with larger number of leaves and found that 16 and 32 are apparently quite a bit faster overall than 8.  left it at 32 for now.
when choosing children to promote, use a sliding range to capture as many tombstones as possible.  also, experimented with larger number of leaves and found that 16 and 32 are apparently quite a bit faster overall than 8.  left it at 32 for now.

zumero/Elmo,zumero/Elmo