Bug #8095: [patch] gc: fix unlimited memory growth with large values of RUBY_FREE_MIN

• Status: Closed
• Assignee: authorNari (Narihiro Nakamura)
• Target version: -
• ruby -v: ruby 2.1.0dev (2013-03-14 trunk 39748) [x86_64-darwin12.2.1]

[tmm1 (Aman Karmani)]

Normally, do_heap_free is set to 65% of total slots available.

But if you specify a very large RUBY_FREE_MIN, then do_heap_free is always set to 100%. This results in a memory leak over time.
Instead of forcing do_heap_free = 100%, the following patch sets do_heap_free = max( RUBY_FREE_MIN, 65% )

diff --git a/gc.c b/gc.c
index bd95073..4103af6 100644
--- a/gc.c
+++ b/gc.c
@@ -1973,8 +1973,9 @@ before_gc_sweep(rb_objspace_t *objspace)
objspace->heap.do_heap_free = (size_t)((heaps_used * HEAP_OBJ_LIMIT) * 0.65);
objspace->heap.free_min = (size_t)((heaps_used * HEAP_OBJ_LIMIT) * 0.2);
if (objspace->heap.free_min < initial_free_min) {

•   objspace->heap.do_heap_free = heaps_used * HEAP_OBJ_LIMIT;
     objspace->heap.free_min = initial_free_min;
  

•    if (objspace->heap.do_heap_free < initial_free_min)
  

•        objspace->heap.do_heap_free = initial_free_min;
  

  }
  objspace->heap.sweep_slots = heaps;
  objspace->heap.free_num = 0;

[authorNari (Narihiro Nakamura)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r39810.
Aman, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• gc.c: Fix unlimited memory growth with large values of
  RUBY_FREE_MIN. patched by tmm1(Aman Gupta).
  [Bug #8095] [ruby-core:53405]