The patch titled
Subject: hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page()
has been added to the -mm tree. Its filename is
hugetlbfs-call-vm_bug_on_page-earlier-in-free_huge_page.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/hugetlbfs-call-vm_bug_on_page-earlier-in-free_huge_page.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/hugetlbfs-call-vm_bug_on_page-earlier-in-free_huge_page.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Yongkai Wu <nic.wuyk@xxxxxxxxx>
Subject: hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page()
A stack trace was triggered by VM_BUG_ON_PAGE(page_mapcount(page), page)
in free_huge_page(). Unfortunately, the page->mapping field was set to
NULL before this test. This made it more difficult to determine the root
cause of the problem.
Move the VM_BUG_ON_PAGE tests earlier in the function so that if they do
trigger more information is present in the page struct.
Link: http://lkml.kernel.org/r/1543491843-23438-1-git-send-email-nic_w@xxxxxxx
Signed-off-by: Yongkai Wu <nic_w@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Acked-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/mm/hugetlb.c~hugetlbfs-call-vm_bug_on_page-earlier-in-free_huge_page
+++ a/mm/hugetlb.c
@@ -1248,10 +1248,11 @@ void free_huge_page(struct page *page)
(struct hugepage_subpool *)page_private(page);
bool restore_reserve;
- set_page_private(page, 0);
- page->mapping = NULL;
VM_BUG_ON_PAGE(page_count(page), page);
VM_BUG_ON_PAGE(page_mapcount(page), page);
+
+ set_page_private(page, 0);
+ page->mapping = NULL;
restore_reserve = PagePrivate(page);
ClearPagePrivate(page);
_
Patches currently in -mm which might be from nic.wuyk@xxxxxxxxx are
hugetlbfs-call-vm_bug_on_page-earlier-in-free_huge_page.patch
