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Date: Wed, 28 Feb 2024 15:40:08 +0800
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Subject: Re: [PATCH 2/3] mm: hugetlb: make the hugetlb migration strategy
 consistent
To: Oscar Salvador <osalvador@suse.de>
Cc: akpm@linux-foundation.org, muchun.song@linux.dev, david@redhat.com,
 linmiaohe@huawei.com, naoya.horiguchi@nec.com, mhocko@kernel.org,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org
References: <cover.1709041586.git.baolin.wang@linux.alibaba.com>
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From: Baolin Wang <baolin.wang@linux.alibaba.com>
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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.