Re: [Patch v3] mm/page_alloc.c: use NODE_MASK_NONE define used_mask

From: Wei Yang
Date: Sun Mar 29 2020 - 02:19:10 EST


On Sat, Mar 28, 2020 at 09:00:26PM -0700, John Hubbard wrote:
>On 3/28/20 7:42 PM, Wei Yang wrote:
>> For all 0 nodemask_t, we have already define macro NODE_MASK_NONE.
>> Leverage this to define an all clear nodemask.
>
>It would be a little clearer if you used wording more like this:
>
>Subject: [Patch v3] mm/page_alloc.c: use NODE_MASK_NONE in build_zonelists()
>
>Slightly simplify the code by initializing user_mask with
>NODE_MASK_NONE, instead of later calling nodes_clear(). This saves
>a line of code.
>

Thanks, the wording is better.

>
>>
>> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
>>
>> ---
>> v3: adjust the commit log a little
>> v2: use NODE_MASK_NONE as suggested by David Hildenbrand
>> ---
>> mm/page_alloc.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index ef790dfad6aa..dfcf2682ed40 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -5587,14 +5587,13 @@ static void build_zonelists(pg_data_t *pgdat)
>> {
>> static int node_order[MAX_NUMNODES];
>> int node, load, nr_nodes = 0;
>> - nodemask_t used_mask;
>> + nodemask_t used_mask = NODE_MASK_NONE;
>> int local_node, prev_node;
>> /* NUMA-aware ordering of nodes */
>> local_node = pgdat->node_id;
>> load = nr_online_nodes;
>> prev_node = local_node;
>> - nodes_clear(used_mask);
>> memset(node_order, 0, sizeof(node_order));
>> while ((node = find_next_best_node(local_node, &used_mask)) >= 0) {
>>
>
>Honestly, I don't think it's really worth doing a patch for this, but
>there's nothing wrong with the diff, so:
>
>Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
>

Thanks.

>
>thanks,
>--
>John Hubbard
>NVIDIA

--
Wei Yang
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