[PATCH] malloc: retire mechanism for older non used tcached chunks

[Florian Weimer]

* Cupertino Miranda:

>>> +      while (tcache_tmp->return_to_arena)
>>> +	{
>>> +	  tcache_entry *e = tcache_tmp->return_to_arena;
>>> +	  if (__glibc_unlikely (misaligned_mem (e)))
>>> +	    malloc_printerr ("tcache_thread_shutdown(): "
>>> +			     "unaligned tcache chunk detected");
>>> +	  tcache_tmp->return_to_arena = REVEAL_PTR (e->next);
>>> +	  __libc_free (e);
>> These needs a comment why this actually returns allocations to the
>> arena.  And if it doesn't why this isn't necessary.

> I don't know if I understand what you mean. It always does it in that
> loop, right? The loop traverses the bin freeing all those chunks.
> One mistake I notice there is the call to __libc_free, instead of
> _int_free_chunk, locking the arena only once instead of for each
> chunk.

Well, that's what I meant. 8-)

I haven't done an in-depth review of the patch, and I may not have time
soon to look into it further.

Thanks,
Florian