Re: [PATCH v2 05/10] mm, hugetlb: fix and clean-up node iteration code to alloc or free

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Michal Hocko <mhocko@suse.cz> writes:

> On Mon 22-07-13 17:36:26, Joonsoo Kim wrote:
>> Current node iteration code have a minor problem which do one more
>> node rotation if we can't succeed to allocate. For example,
>> if we start to allocate at node 0, we stop to iterate at node 0.
>> Then we start to allocate at node 1 for next allocation.
>> 
>> I introduce new macros "for_each_node_mask_to_[alloc|free]" and
>> fix and clean-up node iteration code to alloc or free.
>> This makes code more understandable.
>
> I don't know but it feels like you are trying to fix an awkward
> interface with another one. Why hstate_next_node_to_alloc cannot simply
> return MAX_NUMNODES once the loop is done and start from first_node next
> time it is called? We wouldn't have the bug you are mentioning and you
> do not need scary looking macros.
>

Even though the macros looks confusing, the changes do help rest of the
code. for ex: I liked how it made alloc simpler.

 +	for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
 +		page = alloc_fresh_huge_page_node(h, node);

-aneesh