linux-kernel - Re: [PATCH mm-new v4 6/6] mm: khugepaged: set to next mm direct when mm has MMF_DISABLE_THP

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Message-ID: <c80d4095-a72c-4830-883e-93ed18600a2b@kernel.org>
Date: Wed, 14 Jan 2026 12:52:25 +0100
From: "David Hildenbrand (Red Hat)" <david@...nel.org>
To: Vernon Yang <vernon2gm@...il.com>, akpm@...ux-foundation.org
Cc: lorenzo.stoakes@...cle.com, ziy@...dia.com, dev.jain@....com,
 baohua@...nel.org, lance.yang@...ux.dev, linux-mm@...ck.org,
 linux-kernel@...r.kernel.org, Vernon Yang <yanglincheng@...inos.cn>
Subject: Re: [PATCH mm-new v4 6/6] mm: khugepaged: set to next mm direct when
 mm has MMF_DISABLE_THP_COMPLETELY

On 1/11/26 13:19, Vernon Yang wrote:
> When an mm with the MMF_DISABLE_THP_COMPLETELY flag is detected during
> scanning, directly set khugepaged_scan.mm_slot to the next mm_slot,
> reduce redundant operation.
> 
> Without this patch, entering khugepaged_scan_mm_slot() next time, we
> will set khugepaged_scan.mm_slot to the next mm_slot.
> 
> With this patch, we will directly set khugepaged_scan.mm_slot to the
> next mm_slot.
> 
> Signed-off-by: Vernon Yang <yanglincheng@...inos.cn>
> ---
>   mm/khugepaged.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 8a7008760566..4c055d6c2717 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -2566,7 +2566,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result
>   	 * Release the current mm_slot if this mm is about to die, or
>   	 * if we scanned all vmas of this mm.
>   	 */
> -	if (hpage_collapse_test_exit(mm) || !vma) {
> +	if (hpage_collapse_test_exit_or_disable(mm) || !vma) {
>   		/*
>   		 * Make sure that if mm_users is reaching zero while
>   		 * khugepaged runs here, khugepaged_exit will find

collect_mm_slot() should do the right thing when disabled and just keep 
it on the list.

So this LGTM

Acked-by: David Hildenbrand (Red Hat) <david@...nel.org>

-- 
Cheers

David