Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | alexs@kernel ... | Subject | [PATCH 01/12] mm/ksm: catch tail page abnormal in page_stable_node | Date | Mon, 18 Mar 2024 20:14:30 +0800 |
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From: Alex Shi <alexs@kernel.org>
commit 19138349ed59 ("mm/migrate: Add folio_migrate_flags()") change the meaning of func page_stable_node() to check the compound head for tail 'page' instead of tail page self. But seems both semantics are same at results, the func always return NULL for tail page. So adding a bug monitor here in case of abnormal.
Signed-off-by: Alex Shi <alexs@kernel.org> Cc: Izik Eidus <izik.eidus@ravellosystems.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Chris Wright <chrisw@sous-sol.org> To: linux-kernel@vger.kernel.org To: linux-mm@kvack.org To: Andrew Morton <akpm@linux-foundation.org> --- mm/ksm.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/mm/ksm.c b/mm/ksm.c index 8c001819cf10..3ff469961927 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1091,7 +1091,12 @@ static inline struct ksm_stable_node *folio_stable_node(struct folio *folio) static inline struct ksm_stable_node *page_stable_node(struct page *page) { - return folio_stable_node(page_folio(page)); + struct ksm_stable_node *node; + + node = folio_stable_node(page_folio(page)); + VM_BUG_ON_PAGE(PageTail(page) && node, page); + + return node; } static inline void set_page_stable_node(struct page *page, -- 2.43.0
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