+ mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack.patch added to mm-unstable branch

+ mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: mmap: no need to call khugepaged_enter_vma() for stack
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Yang Shi <yang@os.amperecomputing.com>
Subject: mm: mmap: no need to call khugepaged_enter_vma() for stack
Date: Wed, 20 Dec 2023 22:59:42 -0800

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.

Link: https://lkml.kernel.org/r/20231221065943.2803551-1-shy828301@gmail.com
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmap.c |    2 --
 1 file changed, 2 deletions(-)

--- a/mm/mmap.c~mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack
+++ a/mm/mmap.c
@@ -2049,7 +2049,6 @@ static int expand_upwards(struct vm_area
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma(vma, vma->vm_flags);
 	mas_destroy(&mas);
 	validate_mm(mm);
 	return error;
@@ -2143,7 +2142,6 @@ int expand_downwards(struct vm_area_stru
 		}
 	}
 	anon_vma_unlock_write(vma->anon_vma);
-	khugepaged_enter_vma(vma, vma->vm_flags);
 	mas_destroy(&mas);
 	validate_mm(mm);
 	return error;
_

Patches currently in -mm which might be from yang@os.amperecomputing.com are

mm-mmap-no-need-to-call-khugepaged_enter_vma-for-stack.patch
mm-mmap-map-map_stack-to-vm_nohugepage.patch