Re: [PATCH v6 4/6] mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY

[Mike Kravetz]

On 7/22/21 2:42 AM, Michal Hocko wrote:
> On Wed 21-07-21 13:49:15, Mike Kravetz wrote:
>> On 7/12/21 1:09 AM, Feng Tang wrote:
> [...]
>>> +#ifdef CONFIG_NUMA
>>> +	if (mpol->mode == MPOL_PREFERRED_MANY) {
>>> +		gfp_t gfp = (gfp_mask | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM;
>>
>> I believe __GFP_NOWARN will be added later in alloc_buddy_huge_page, so
>> no need to add here?
> 
> The mask is manipulated here anyway and the __GFP_NOWARN is really
> telling that there is no need to report the failure for _this_
> allocation request. alloc_surplus_huge_page might alter that in whatever
> way in the future. So I would keep NOWARN here for the code clarity
> rather than rely on some implicit assumption down the path.

Makes sense.  Better to leave the __GFP_NOWARN here for clarity.

-- 
Mike Kravetz