linux-kernel - Re: [PATCH 06/10] mm/hugetlb: remove redundant huge_pte_alloc() in hugetlb

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Message-ID: <20200807125928.GQ14854@MiWiFi-R3L-srv>
Date:   Fri, 7 Aug 2020 20:59:28 +0800
From:   Baoquan He <bhe@...hat.com>
To:     Wei Yang <richard.weiyang@...ux.alibaba.com>
Cc:     mike.kravetz@...cle.com, akpm@...ux-foundation.org,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 06/10] mm/hugetlb: remove redundant huge_pte_alloc() in
 hugetlb_fault()

On 08/07/20 at 05:12pm, Wei Yang wrote:
> Before proper processing, huge_pte_alloc() would be called
> un-conditionally. It is not necessary to do this when ptep is NULL.
> 
> Signed-off-by: Wei Yang <richard.weiyang@...ux.alibaba.com>
> ---
>  mm/hugetlb.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index f5f04e89000d..fb09e5a83c39 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4534,10 +4534,6 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
>  		} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
>  			return VM_FAULT_HWPOISON_LARGE |
>  				VM_FAULT_SET_HINDEX(hstate_index(h));
> -	} else {
> -		ptep = huge_pte_alloc(mm, haddr, huge_page_size(h));
> -		if (!ptep)
> -			return VM_FAULT_OOM;

Right, seems a relic from Mike's i_mmap_rwsem handling patches.

Reviewed-by: Baoquan He <bhe@...hat.com>

>  	}
>  
>  	/*
> -- 
> 2.20.1 (Apple Git-117)
> 
>