The patch titled
Subject: mm/hugetlb: fix gigantic page initialization/allocation
has been removed from the -mm tree. Its filename was
mm-hugetlb-fix-gigantic-page-initialization-allocation.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Subject: mm/hugetlb: fix gigantic page initialization/allocation
Attempting to preallocate 1G gigantic huge pages at boot time with
"hugepagesz=1G hugepages=1" on the kernel command line will prevent
booting with the following:
kernel BUG at mm/hugetlb.c:1218!
When mapcount accounting was reworked, the setting of
compound_mapcount_ptr in prep_compound_gigantic_page was overlooked. As a
result, the validation of mapcount in free_huge_page fails.
The "BUG_ON" checks in free_huge_page were also changed to "VM_BUG_ON_PAGE"
to assist with debugging.
Fixes: 53f9263baba69 ("mm: rework mapcount accounting to enable 4k mapping of THPs")
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Tested-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff -puN mm/hugetlb.c~mm-hugetlb-fix-gigantic-page-initialization-allocation mm/hugetlb.c
--- a/mm/hugetlb.c~mm-hugetlb-fix-gigantic-page-initialization-allocation
+++ a/mm/hugetlb.c
@@ -1214,8 +1214,8 @@ void free_huge_page(struct page *page)
set_page_private(page, 0);
page->mapping = NULL;
- BUG_ON(page_count(page));
- BUG_ON(page_mapcount(page));
+ VM_BUG_ON_PAGE(page_count(page), page);
+ VM_BUG_ON_PAGE(page_mapcount(page), page);
restore_reserve = PagePrivate(page);
ClearPagePrivate(page);
@@ -1286,6 +1286,7 @@ static void prep_compound_gigantic_page(
set_page_count(p, 0);
set_compound_head(p, page);
}
+ atomic_set(compound_mapcount_ptr(page), -1);
}
/*
_
Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are
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