Re: memory leak in reorg_loops

[Jeff Law <law at redhat dot com>]

On 01/07/14 06:57, Richard Biener wrote:
> On Mon, Jan 6, 2014 at 6:24 PM, Jeff Law <law@redhat.com> wrote:
> > On 01/02/14 19:31, dxq wrote:
> > > hi,
> > >
> > > In hw-doloop.c,  is there a memory leak?
> > >
> > > valgrind checking shows:
> > >
> > > ==18622== 1,479,296 bytes in 364 blocks are definitely lost in loss record
> > > 559 of 559
> > > ==18622==    at 0x4006ADD: malloc (vg_replace_malloc.c:291)
> > > ==18622==    by 0x8C0A9D5: xmalloc (xmalloc.c:147)
> > > ==18622==    by 0x910457: _obstack_begin (in /lib/libc-2.5.so)
> > > ==18622==    by 0x81EDD24: bitmap_obstack_initialize (bitmap.c:318)
> > > ==18622==    by 0x8B22BBE: reorg_loops (hw-doloop.c:635)
> > > ...
> > > ...
> > > ==18622==    by 0x8688B3E: rest_of_handle_machine_reorg (reorg.c:4183)
> > > ==18622==    by 0x861D2A6: execute_one_pass (passes.c:2097)
> > > ==18622==    by 0x861D6A0: execute_pass_list (passes.c:2152)
> > > ==18622==    by 0x861D6BC: execute_pass_list (passes.c:2153)
> > > ==18622==    by 0x861D6BC: execute_pass_list (passes.c:2153)
> > >
> > > should loop_stack be freed at the end of reorg_loops? please confirm!
> > > if it's true, commit for me, thanks!
> > >
> > >       free_loops (loops);
> > > +  bitmap_obstack_release (&loop_stack);
> > >
> > >      if (dump_file)
> > >        print_rtl (dump_file, get_insns ());
> > >
> > > thanks!
> >
> > Isn't the bitmap free'd from within free_loops?
>
> It isn't (it's hw-doloops 'loop' structures).
I realize it's hw-doloops loop structures.  I was referring to the 
BITMAP_FREE of the underlying bitmaps in free_loops.  But if I'm reading 
everything correctly that puts stuff on the free list.  To actually 
release things back we need the bitmap_obstack_release.

> The patch is ok.
Installed.

Jeff