Re: [RFC PATCH 1/3] kmemleak: Allow partial freeing of memory blocks

Pekka Enberg
2009-07-08T06:34:17Z

On Tue, 2009-07-07 at 14:39 +0100, Catalin Marinas wrote:
> @@ -552,8 +557,27 @@ static void delete_object(unsigned long ptr)
> */
> spin_lock_irqsave(&object->lock, flags);
> object->flags &= ~OBJECT_ALLOCATED;
> + start = object->pointer;
> + end = object->pointer + object->size;
> + min_count = object->min_count;
> spin_unlock_irqrestore(&object->lock, flags);
> put_object(object);
> +
> + if (!size)
> + return;
> +
> + /*
> + * Partial freeing. Just create one or two objects that may result
> + * from the memory block split. Note that partial freeing is only done
> + * by free_bootmem() and this happens before kmemleak_init() is
> + * called. The path below is only executed during early log recording
> + * in kmemleak_init(), so GFP_KERNEL is enough.
> + */
> + if (ptr > start)
> + create_object(start, ptr - start, min_count, GFP_KERNEL);
> + if (ptr + size < end)
> + create_object(ptr + size, end - ptr - size, min_count,
> + GFP_KERNEL);
> }

Looks good to me. I think it would be better to have
delete_object_full() and delete_object_part(), and extract the common
code to __delete_object() or something instead of passing the magic zero
from kmemleak_free().

In any case:

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>

Pekka