Commit 5a571434 authored Apr 16, 2024 by Yang Shi Committed by Kefeng Wang Apr 16, 2024

mm: mmap: no need to call khugepaged_enter_vma() for stack

mainline inclusion
from mainline-v6.9-rc1
commit 05976a42b327d4f5a529a5e55cb8bfc2fa0bcca1
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9H84X
CVE: NA

-------------------------------------------------

We avoid allocating THP for temporary stack, even though
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>
(cherry picked from commit 05976a42b327d4f5a529a5e55cb8bfc2fa0bcca1)
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

parent ea413770

mm/mmap.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -2069,7 +2069,6 @@ 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;
		@@ -2163,7 +2162,6 @@ 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;