Re: [PATCH 2/3] mm: hugetlb: make the hugetlb migration strategy consistent

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 2024/2/27 23:17, Oscar Salvador wrote:
> On Tue, Feb 27, 2024 at 09:52:26PM +0800, Baolin Wang wrote:
> 
>> --- a/mm/hugetlb.c
>> +++ b/mm/hugetlb.c
>> @@ -2567,13 +2567,38 @@ static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h,
>>   }
>>   
>>   static struct folio *alloc_migrate_hugetlb_folio(struct hstate *h, gfp_t gfp_mask,
>> -				     int nid, nodemask_t *nmask)
>> +				     int nid, nodemask_t *nmask, int reason)
> 
> I still dislike taking the reason argument this far, and I'd rather have
> this as a boolean specifing whether we allow fallback on other nodes.
> That would mean parsing the reason in alloc_migration_target().
> If we don't add a new helper e.g: gfp_allow_fallback(), we can just do
> it right there an opencode it with a e.g: macro etc.
> 
> Although doing it in an inline helper might help hiding these details.
> 
> That's my take on this, but let's see what others have to say.

Sure. I also expressed my preference for hiding these details within the 
hugetlb core as much as possible.

Muchun, what do you think? Thanks.