[v3 PATCH 1/7] mm: khugepaged: check THP flag in hugepage_vma_check()

From: Yang Shi <shy828301@gmail.com>
To: vbabka@suse.cz, kirill.shutemov@linux.intel.com,
	willy@infradead.org, akpm@linux-foundation.org
Cc: shy828301@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [v3 PATCH 1/7] mm: khugepaged: check THP flag in hugepage_vma_check()
Date: Mon,  6 Jun 2022 14:44:08 -0700	[thread overview]
Message-ID: <20220606214414.736109-2-shy828301@gmail.com> (raw)
In-Reply-To: <20220606214414.736109-1-shy828301@gmail.com>

Currently the THP flag check in hugepage_vma_check() will fallthrough if
the flag is NEVER and VM_HUGEPAGE is set.  This is not a problem for now
since all the callers have the flag checked before or can't be invoked if
the flag is NEVER.

However, the following patch will call hugepage_vma_check() in more
places, for example, page fault, so this flag must be checked in
hugepge_vma_check().

Signed-off-by: Yang Shi <shy828301@gmail.com>
---
 mm/khugepaged.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 671ac7800e53..84b9cf4b9be9 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -458,6 +458,9 @@ bool hugepage_vma_check(struct vm_area_struct *vma,
 	if (shmem_file(vma->vm_file))
 		return shmem_huge_enabled(vma);
 
+	if (!khugepaged_enabled())
+		return false;
+
 	/* THP settings require madvise. */
 	if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always())
 		return false;
-- 
2.26.3

