linux-kernel - Re: [PATCH v2 3/7] mm: introduce do_zap_pte

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Message-ID: <db3cd6c1-03d6-48fd-9591-ab3e90d7e10f@redhat.com>
Date: Tue, 12 Nov 2024 18:00:27 +0100
From: David Hildenbrand <david@...hat.com>
To: Qi Zheng <zhengqi.arch@...edance.com>, jannh@...gle.com,
 hughd@...gle.com, willy@...radead.org, mgorman@...e.de,
 muchun.song@...ux.dev, vbabka@...nel.org, akpm@...ux-foundation.org,
 zokeefe@...gle.com, rientjes@...gle.com, peterx@...hat.com,
 catalin.marinas@....com
Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH v2 3/7] mm: introduce do_zap_pte_range()

On 31.10.24 09:13, Qi Zheng wrote:
> This commit introduces do_zap_pte_range() to actually zap the PTEs, which
> will help improve code readability and facilitate secondary checking of
> the processed PTEs in the future.
> 
> No functional change.
> 
> Signed-off-by: Qi Zheng <zhengqi.arch@...edance.com>
> ---
>   mm/memory.c | 45 ++++++++++++++++++++++++++-------------------
>   1 file changed, 26 insertions(+), 19 deletions(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index bd9ebe0f4471f..c1150e62dd073 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1657,6 +1657,27 @@ static inline int zap_nonpresent_ptes(struct mmu_gather *tlb,
>   	return nr;
>   }
>   
> +static inline int do_zap_pte_range(struct mmu_gather *tlb,
> +				   struct vm_area_struct *vma, pte_t *pte,
> +				   unsigned long addr, unsigned long end,
> +				   struct zap_details *details, int *rss,
> +				   bool *force_flush, bool *force_break)
> +{
> +	pte_t ptent = ptep_get(pte);
> +	int max_nr = (end - addr) / PAGE_SIZE;
> +
> +	if (pte_none(ptent))
> +		return 1;

Maybe we should just skip all applicable pte_none() here directly.

Acked-by: David Hildenbrand <david@...hat.com>

-- 
Cheers,

David / dhildenb