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Date: Thu, 22 Jan 2026 14:58:15 +0530
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Subject: Re: [PATCH V3 5/5] mm/khugepaged: make khugepaged_collapse_control
 static
To: Shivank Garg <shivankg@amd.com>, Andrew Morton
 <akpm@linux-foundation.org>, David Hildenbrand <david@kernel.org>,
 Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>, Baolin Wang <baolin.wang@linux.alibaba.com>,
 "Liam R . Howlett" <Liam.Howlett@oracle.com>, Nico Pache
 <npache@redhat.com>, Ryan Roberts <ryan.roberts@arm.com>,
 Barry Song <baohua@kernel.org>, Lance Yang <lance.yang@linux.dev>,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org,
 Wei Yang <richard.weiyang@gmail.com>,
 Anshuman Khandual <anshuman.khandual@arm.com>
References: <20260118192253.9263-4-shivankg@amd.com>
 <20260118192253.9263-14-shivankg@amd.com>
Content-Language: en-US
From: Dev Jain <dev.jain@arm.com>
In-Reply-To: <20260118192253.9263-14-shivankg@amd.com>
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On 19/01/26 12:53 am, Shivank Garg wrote:
> The global variable 'khugepaged_collapse_control' is not used outside of
> mm/khugepaged.c. Make it static to limit its scope.
>
> Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> Signed-off-by: Shivank Garg <shivankg@amd.com>
> ---
>  mm/khugepaged.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 1667abae6d8d..fba6aea5bea6 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -827,7 +827,7 @@ static void khugepaged_alloc_sleep(void)
>  	remove_wait_queue(&khugepaged_wait, &wait);
>  }
>  
> -struct collapse_control khugepaged_collapse_control = {
> +static struct collapse_control khugepaged_collapse_control = {
>  	.is_khugepaged = true,
>  };
>  

Will it not be better to just remove this variable? In madvise_collapse,
we defined cc as a local variable and set .is_khugepaged = false. The
same can be done in int khugepaged() - define a local variable and set
.is_khugepaged = true.