gc.c: introduce tomb heap. Tomb heap is where zombie objects and ghost (freed slot) lived in. Separate from other heaps (now there is only eden heap) at sweeping helps freeing pages more efficiently. Before this patch, even if there is an empty page at former phase of sweeping, we can't free it. Algorithm: (1) Sweeping all pages in a heap and move empty pages from the heap to tomb_heap. (2) Check all exsisting pages and free a page if all slots of this page are empty and there is enough empty slots (checking by swept_num) To introduce this pach, there are several tuning of GC parameters.
Added by ko1 (Koichi Sasada) about 12 years ago
Tomb heap is where zombie objects and ghost (freed slot) lived in.
Separate from other heaps (now there is only eden heap) at sweeping
helps freeing pages more efficiently.
Before this patch, even if there is an empty page at former phase
of sweeping, we can't free it.
Algorithm:
(1) Sweeping all pages in a heap and move empty pages from the
heap to tomb_heap.
(2) Check all exsisting pages and free a page
if all slots of this page are empty and
there is enough empty slots (checking by swept_num)
To introduce this pach, there are several tuning of GC parameters.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43395 b2dd03c8-39d4-4d8f-98ff-823fe69b080e