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Date:   Tue, 6 Jun 2023 14:43:21 -0400
From:   "Liam R. Howlett" <Liam.Howlett@Oracle.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Hugh Dickins <hughd@google.com>,
        "Yin, Fengwei" <fengwei.yin@intel.com>,
        Peng Zhang <zhangpeng.00@bytedance.com>,
        maple-tree@lists.infradead.org
Subject: Re: [PATCH] mm: Update validate_mm() to use vma iterator CONFIG flag
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        "Yin, Fengwei" <fengwei.yin@intel.com>,
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References: <20230606183538.588190-1-Liam.Howlett@oracle.com>
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Sorry, I should have added some more Cc's here.

* Liam R. Howlett <Liam.Howlett@oracle.com> [230606 14:35]:
> The validate_mm() function was deemed too heavy to enable with
> CONFIG_DEBUG_VM [1].  Revert the config option to
> CONFIG_DEBUG_VM_MAPLE_TREE
> 
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
> 
> Andrew,
> 
> Please squash this into your mm-unstable commit e9c9b8e9753d ("mm:
> update validate_mm() to use vma iterator")
> 
>  mm/mmap.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 71733953ff83..7c106a164c0f 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -299,7 +299,7 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
>  	return origbrk;
>  }
>  
> -#if defined(CONFIG_DEBUG_VM)
> +#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
>  static void validate_mm(struct mm_struct *mm)
>  {
>  	int bug = 0;
> @@ -307,10 +307,7 @@ static void validate_mm(struct mm_struct *mm)
>  	struct vm_area_struct *vma;
>  	VMA_ITERATOR(vmi, mm, 0);
>  
> -#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
>  	mt_validate(&mm->mm_mt);
> -#endif
> -
>  	for_each_vma(vmi, vma) {
>  #ifdef CONFIG_DEBUG_VM_RB
>  		struct anon_vma *anon_vma = vma->anon_vma;
> @@ -353,9 +350,9 @@ static void validate_mm(struct mm_struct *mm)
>  	VM_BUG_ON_MM(bug, mm);
>  }
>  
> -#else /* !CONFIG_DEBUG_VM */
> +#else /* !CONFIG_DEBUG_VM_MAPLE_TREE */
>  #define validate_mm(mm) do { } while (0)
> -#endif /* CONFIG_DEBUG_VM */
> +#endif /* CONFIG_DEBUG_VM_MAPLE_TREE */
>  
>  /*
>   * vma has some anon_vma assigned, and is already inserted on that
> -- 
> 2.39.2
>