From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B0424381A1 for ; Mon, 18 Mar 2024 12:11:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710763881; cv=none; b=mGw3VNU7GCAcx37z6xAYgRQF5hXNuTCSRj2ZwxwTbzDr2QXKn3L4oJQVfWJMi8tNe13hyXu/9OlrFH6k/dn2FR8MImuxA9B4QvXYrmFIwWUg2N5KQch9gktANW61wdx+jAJu+Cq6xXplDyTDg8sNES6se0FHWERS+vDqNDwfYAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710763881; c=relaxed/simple; bh=JGYfbRVIlHuHoI0NmXjtxepKc6ayun3xXlgDn4j46pw=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=NKo3AZzvO7yhfo2sfRDADYYnAIENyIEorGGD2pnZSOUFaaI/g433KDP/r0ODHfaHBFStWlt/blHYWw0+KOZIKQR97nrkDLW5dDw87gSwtJ6thpzTNYDiM+9+jokTR/AKGodtRRev1khLdZ1XspHaM8xOxMyXy652bjwQB9HqZrA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qhNCPdXY; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qhNCPdXY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A178C433F1; Mon, 18 Mar 2024 12:11:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710763881; bh=JGYfbRVIlHuHoI0NmXjtxepKc6ayun3xXlgDn4j46pw=; h=From:To:Subject:Date:From; b=qhNCPdXYMkprcVdjnMn62xTr1ev9QT80OeSwydB8rxi2JOdRpMbLfbVXABSBeqO/B QNn+lahk2HRco7Ry/mGwVwYXVhIJLQ2+vxjol3pMpexnomkDo1Az+EEj2IG3ZF4el1 sZqhtbj56qd+zBEiKBb6DkBfjX3ta6qqWlM7LLsTPx7SdIjd+BVi+MgVNksfGWnS1h SefuNpistEXlrQ3w9/+za8sLv4iS7nnwfoG6Fm89v+IoF1VemtGdNlml6j6rWgq2pY SmDsBHVyqF8tWaY6pj1lYDpJBHglTnCVyTnLA7bG2/QzrvSBqnzl4olfVuaIO022CA ZlvQG2kuW3KxA== From: alexs@kernel.org To: kasong@tencent.com, Andrew Morton , linux-mm@kvack.org (open list:MEMORY MANAGEMENT), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 01/12] mm/ksm: catch tail page abnormal in page_stable_node Date: Mon, 18 Mar 2024 20:14:30 +0800 Message-ID: <20240318121443.3991104-1-alexs@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Alex Shi 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 Cc: Izik Eidus Cc: Matthew Wilcox Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Chris Wright To: linux-kernel@vger.kernel.org To: linux-mm@kvack.org To: Andrew Morton --- 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