Re: [PATCH -mm 2/7] mm: get unmapped area from VMA tree

[Rik van Riel <riel@redhat.com>]

On 06/21/2012 05:01 AM, Johannes Weiner wrote:

>> +		/* Go left if it looks promising. */
>> +		if (node_free_hole(rb_node->rb_left)>= len&&
>> +					vma->vm_start - len>= lower_limit) {
>> +			rb_node = rb_node->rb_left;
>> +			continue;
>
> If we already are at a vma whose start has a lower address than the
> overall length, does it make sense to check for a left hole?
> I.e. shouldn't this be inside the if (vma->vm_start>  len) block?

You are right, I can move this in under the
conditional.

>> +		if (!found_here&&  node_free_hole(rb_node->rb_left)>= len) {
>> +			/* Last known hole is to the right of this subtree. */
>
> "to the left"

Actually, it is to the right.  We walked left from
our parent to get here, so the holes found so far
are to the right of here.