[merged mm-stable] mm-thp-remove-redundant-pgtable-check-in-set_huge_zero_page.patch removed from -mm tree

[merged mm-stable] mm-thp-remove-redundant-pgtable-check-in-set_huge_zero_page.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: thp: remove redundant pgtable check in set_huge_zero_page()
has been removed from the -mm tree.  Its filename was
     mm-thp-remove-redundant-pgtable-check-in-set_huge_zero_page.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: thp: remove redundant pgtable check in set_huge_zero_page()
Date: Thu, 18 Aug 2022 16:27:48 +0800

When the pgtable is NULL in the set_huge_zero_page(), we should not
increment the count of PTE page table pages by calling mm_inc_nr_ptes(). 
Otherwise we may receive the following warning when the mm exits:

	BUG: non-zero pgtables_bytes on freeing mm

Now we can't observe the above warning since only
do_huge_pmd_anonymous_page() invokes set_huge_zero_page() and the pgtable
can not be NULL.

Therefore, instead of moving mm_inc_nr_ptes() to the non-NULL branch of
pgtable, it is better to remove the redundant pgtable check directly.

Link: https://lkml.kernel.org/r/20220818082748.40021-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/huge_memory.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/huge_memory.c~mm-thp-remove-redundant-pgtable-check-in-set_huge_zero_page
+++ a/mm/huge_memory.c
@@ -770,8 +770,7 @@ static void set_huge_zero_page(pgtable_t
 		return;
 	entry = mk_pmd(zero_page, vma->vm_page_prot);
 	entry = pmd_mkhuge(entry);
-	if (pgtable)
-		pgtable_trans_huge_deposit(mm, pmd, pgtable);
+	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, haddr, pmd, entry);
 	mm_inc_nr_ptes(mm);
 }
_

Patches currently in -mm which might be from zhengqi.arch@bytedance.com are

mm-introduce-common-struct-mm_slot.patch
mm-thp-convert-to-use-common-struct-mm_slot.patch
mm-thp-convert-to-use-common-struct-mm_slot-fix.patch
ksm-remove-redundant-declarations-in-ksmh.patch
ksm-add-the-ksm-prefix-to-the-names-of-the-ksm-private-structures.patch
ksm-convert-ksm_mm_slotmm_list-to-ksm_mm_slotmm_node.patch
ksm-convert-ksm_mm_slotlink-to-ksm_mm_slothash.patch
ksm-convert-to-use-common-struct-mm_slot.patch