+ khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch added to -mm tree

+ khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch added to -mm tree

[akpm]

The patch titled
     Subject: khugepaged: use helper khugepaged_test_exit() in __khugepaged_enter()
has been added to the -mm tree.  Its filename is
     khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: khugepaged: use helper khugepaged_test_exit() in __khugepaged_enter()

Commit 4d45e75a9955 ("mm: remove the now-unnecessary mmget_still_valid()
hack") have made khugepaged_test_exit() suitable for check mm->mm_users
against 0.  Use this helper here.

Link: https://lkml.kernel.org/r/20210306032947.35921-4-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/khugepaged.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/khugepaged.c~khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter
+++ a/mm/khugepaged.c
@@ -481,7 +481,7 @@ int __khugepaged_enter(struct mm_struct
 		return -ENOMEM;
 
 	/* __khugepaged_exit() must not run from under us */
-	VM_BUG_ON_MM(atomic_read(&mm->mm_users) == 0, mm);
+	VM_BUG_ON_MM(khugepaged_test_exit(mm), mm);
 	if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) {
 		free_mm_slot(mm_slot);
 		return 0;
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

hugetlb_cgroup-fix-imbalanced-css_get-and-css_put-pair-for-shared-mappings.patch
mm-hugetlb-remove-redundant-reservation-check-condition-in-alloc_huge_page.patch
mm-hugetlb-use-some-helper-functions-to-cleanup-code.patch
mm-hugetlb-optimize-the-surplus-state-transfer-code-in-move_hugetlb_state.patch
hugetlb_cgroup-remove-unnecessary-vm_bug_on_page-in-hugetlb_cgroup_migrate.patch
mm-hugetlb-simplify-the-code-when-alloc_huge_page-failed-in-hugetlb_no_page.patch
mm-hugetlb-avoid-calculating-fault_mutex_hash-in-truncate_op-case.patch
khugepaged-remove-unneeded-return-value-of-khugepaged_collapse_pte_mapped_thps.patch
khugepaged-reuse-the-smp_wmb-inside-__setpageuptodate.patch
khugepaged-use-helper-khugepaged_test_exit-in-__khugepaged_enter.patch
khugepaged-fix-wrong-result-value-for-trace_mm_collapse_huge_page_isolate.patch