linux-kernel - [PATCH 1/2] mm: mmap: no need to call khugepaged_enter

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Date: Wed, 20 Dec 2023 22:59:42 -0800
From: Yang Shi <shy828301@...il.com>
To: oliver.sang@...el.com,
	riel@...riel.com,
	fengwei.yin@...el.com,
	willy@...radead.org,
	cl@...ux.com,
	ying.huang@...el.com,
	akpm@...ux-foundation.org
Cc: shy828301@...il.com,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org
Subject: [PATCH 1/2] mm: mmap: no need to call khugepaged_enter_vma() for stack

From: Yang Shi <yang@...amperecomputing.com>

We avoid allocating THP for temporary stack, even tnough
khugepaged_enter_vma() is called for stack VMAs, it actualy returns
false.  So no need to call it in the first place at all.

Signed-off-by: Yang Shi <yang@...amperecomputing.com>
---
 mm/mmap.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index b78e83d351d2..2ff79b1d1564 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2046,7 +2046,6 @@ static int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma(vma, vma->vm_flags);
 	mas_destroy(&mas);
 	validate_mm(mm);
 	return error;
@@ -2140,7 +2139,6 @@ int expand_downwards(struct vm_area_struct *vma, unsigned long address)
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma(vma, vma->vm_flags);
 	mas_destroy(&mas);
 	validate_mm(mm);
 	return error;
-- 
2.41.0