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

[Wei Yang <richard.weiyang@gmail.com>]

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@gmail.com>
>> 
>> ---
>> 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@nvidia.com>
>

Thanks.

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

-- 
Wei Yang
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