The quilt patch titled
Subject: hugetlb: clear flags in tail pages that will be freed individually
has been removed from the -mm tree. Its filename was
hugetlb-clear-flags-in-tail-pages-that-will-be-freed-individually.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Subject: hugetlb: clear flags in tail pages that will be freed individually
Date: Tue, 22 Aug 2023 15:30:43 -0700
hugetlb manually creates and destroys compound pages. As such it makes
assumptions about struct page layout. Commit ebc1baf5c9b4 ("mm: free up a
word in the first tail page") breaks hugetlb. The following will fix the
breakage.
Link: https://lkml.kernel.org/r/20230822231741.GC4509@monkey
Fixes: ebc1baf5c9b4 ("mm: free up a word in the first tail page")
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
--- a/mm/hugetlb.c~hugetlb-clear-flags-in-tail-pages-that-will-be-freed-individually
+++ a/mm/hugetlb.c
@@ -1484,6 +1484,7 @@ static void __destroy_compound_gigantic_
for (i = 1; i < nr_pages; i++) {
p = folio_page(folio, i);
+ p->flags &= ~PAGE_FLAGS_CHECK_AT_FREE;
p->mapping = NULL;
clear_compound_head(p);
if (!demote)
@@ -1702,8 +1703,6 @@ static void add_hugetlb_folio(struct hst
static void __update_and_free_hugetlb_folio(struct hstate *h,
struct folio *folio)
{
- int i;
- struct page *subpage;
bool clear_dtor = folio_test_hugetlb_vmemmap_optimized(folio);
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
@@ -1745,14 +1744,6 @@ static void __update_and_free_hugetlb_fo
spin_unlock_irq(&hugetlb_lock);
}
- for (i = 0; i < pages_per_huge_page(h); i++) {
- subpage = folio_page(folio, i);
- subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
- 1 << PG_referenced | 1 << PG_dirty |
- 1 << PG_active | 1 << PG_private |
- 1 << PG_writeback);
- }
-
/*
* Non-gigantic pages demoted from CMA allocated gigantic pages
* need to be given back to CMA in free_gigantic_folio.
_
Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are
