On Sat, 11 May 2024 11:54:35 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
> When I did memory failure tests recently, below panic occurs:
>
> kernel BUG at include/linux/mm.h:1135!
> invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 9 PID: 137 Comm: kswapd1 Not tainted 6.9.0-rc4-00491-gd5ce28f156fe-dirty #14
>
> ...
>
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -208,6 +208,7 @@ static bool get_huge_zero_page(void)
> __free_pages(zero_page, compound_order(zero_page));
> goto retry;
> }
> + __SetPageReserved(zero_page);
> WRITE_ONCE(huge_zero_pfn, page_to_pfn(zero_page));
>
> /* We take additional reference here. It will be put back by shrinker */
> @@ -260,6 +261,7 @@ static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink,
> struct page *zero_page = xchg(&huge_zero_page, NULL);
> BUG_ON(zero_page == NULL);
> WRITE_ONCE(huge_zero_pfn, ~0UL);
> + __ClearPageReserved(zero_page);
> __free_pages(zero_page, compound_order(zero_page));
> return HPAGE_PMD_NR;
> }
This causes a bit of a mess when staged ahead of mm-stable. So to
avoid disruption I staged it behind mm-stable. This means that when
the -stable maintainers try to merge it, they will ask for a fixed up
version for older kernels so you can please just send them this
version.
To facilitate this I added the below adjustment:
(btw, shouldn't get_huge_zero_page() and shrink_huge_zero_page_scan()
be renamed to *_folio_*?)
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-huge_memory-mark-huge_zero_page-reserved-fix
Date: Tue May 14 01:53:37 PM PDT 2024
Update it for 5691753d73a2 ("mm: convert huge_zero_page to huge_zero_folio")
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Cc: Xu Yu <xuyu@xxxxxxxxxxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/mm/huge_memory.c~mm-huge_memory-mark-huge_zero_page-reserved-fix
+++ a/mm/huge_memory.c
@@ -212,7 +212,7 @@ retry:
folio_put(zero_folio);
goto retry;
}
- __SetPageReserved(zero_page);
+ __folio_set_reserved(zero_folio);
WRITE_ONCE(huge_zero_pfn, folio_pfn(zero_folio));
/* We take additional reference here. It will be put back by shrinker */
@@ -265,7 +265,7 @@ static unsigned long shrink_huge_zero_pa
struct folio *zero_folio = xchg(&huge_zero_folio, NULL);
BUG_ON(zero_folio == NULL);
WRITE_ONCE(huge_zero_pfn, ~0UL);
- __ClearPageReserved(zero_page);
+ __folio_clear_reserved(zero_folio);
folio_put(zero_folio);
return HPAGE_PMD_NR;
}
_
