Commit adf05a3b authored Apr 16, 2024 by Lance Yang Committed by Kefeng Wang Apr 16, 2024

mm/khugepaged: keep mm in mm_slot without MMF_DISABLE_THP check

mainline inclusion
from mainline-v6.9-rc1
commit 5dad604809c5acc546ec74057498db1623f1c408
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9H84X
CVE: NA

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

Previously, we removed the mm from mm_slot and dropped mm_count
if the MMF_THP_DISABLE flag was set. However, we didn't re-add
the mm back after clearing the MMF_THP_DISABLE flag. Additionally,
We add a check for the MMF_THP_DISABLE flag in hugepage_vma_revalidate().

Link: https://lkml.kernel.org/r/20240227035135.54593-1-ioworker0@gmail.com


Fixes: 879c6000e191 ("mm/khugepaged: bypassing unnecessary scans with MMF_DISABLE_THP check")
Signed-off-by: Lance Yang <ioworker0@gmail.com>
Suggested-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 5dad604809c5acc546ec74057498db1623f1c408)
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>

parent 798109a8

mm/khugepaged.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -928,7 +928,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
		{
		struct vm_area_struct *vma;

		if (unlikely(hpage_collapse_test_exit(mm)))
		if (unlikely(hpage_collapse_test_exit_or_disable(mm)))
		return SCAN_ANY_PROCESS;

		*vmap = vma = find_vma(mm, address);
		@@ -1445,7 +1445,7 @@ static void collect_mm_slot(struct khugepaged_mm_slot *mm_slot)

		lockdep_assert_held(&khugepaged_mm_lock);

		if (hpage_collapse_test_exit_or_disable(mm)) {
		if (hpage_collapse_test_exit(mm)) {
		/* free mm_slot */
		hash_del(&slot->hash);
		list_del(&slot->mm_node);
		@@ -2483,7 +2483,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
		* Release the current mm_slot if this mm is about to die, or
		* if we scanned all vmas of this mm.
		*/
		if (hpage_collapse_test_exit_or_disable(mm) \|\| !vma) {
		if (hpage_collapse_test_exit(mm) \|\| !vma) {
		/*
		* Make sure that if mm_users is reaching zero while
		* khugepaged runs here, khugepaged_exit will find