Re: [PATCH] mm/hugetlb: remove redundant reservation check condition in alloc_huge_page()

From: Miaohe Lin
Date: Wed Feb 17 2021 - 21:27:56 EST


Hi:
On 2021/2/13 9:15, Mike Kravetz wrote:
> On 2/9/21 11:54 PM, Miaohe Lin wrote:
>> If there is no reservation corresponding to a vma, map_chg is always != 0,
>> i.e. we can not meet the condition where a vma does not have reservation
>> while map_chg = 0.
>
> This commit message might be easier to understand?
>
> vma_resv_map(vma) checks if a reserve map is associated with the vma. The
> routine vma_needs_reservation() will check vma_resv_map(vma) and return 1
> if no reserv map is present. map_chg is set to the return value of
> vma_needs_reservation(). Therefore, !vma_resv_map(vma) is redundant in the
> expression:
> map_chg || avoid_reserve || !vma_resv_map(vma);
> Remove the redundant check.
>

Sorry for late respond! I will use this wonderful commit message. Many thanks! :)