In article <1033445508.174360.31838.nullmailer / picachu.netlab.jp>,
  matz / ruby-lang.org (Yukihiro Matsumoto) writes:

> Some reports from valgrind is due to Ruby's conservative GC, which
> touch all C stack region.

I use following suppression file to suppress such reports.

{
  memcpy/rb_thread_save_context(Value1)
  Addr1
  fun:memcpy
  fun:rb_thread_save_context
}

{
  memcpy/rb_thread_restore_context(Value1)
  Addr1
  fun:memcpy
  fun:rb_thread_restore_context
}

{
  strchr/_dl_catch_error(Cond)
  Cond
  fun:strchr
  obj:/lib/libc-2.2.5.so
  fun:_dl_catch_error
}

{
  mark_locations_array(Cond)
  Cond
  fun:mark_locations_array
}

{
  mark_locations_array(Value4)
  Value4
  fun:mark_locations_array
}

{
  mark_locations_array(Value4)
  Addr4
  fun:mark_locations_array
}

{
  rb_gc_mark(Cond)
  Cond
  fun:rb_gc_mark
}

{
  rb_gc_mark(Value4)
  Value4
  fun:rb_gc_mark
}

{
  rb_gc_mark_children(Value4)
  Value4
  fun:rb_gc_mark_children
}

{
  rb_gc_mark_children(Cond)
  Cond
  fun:rb_gc_mark_children
}
-- 
Tanaka Akira