From nobody Sun Feb 8 14:56:14 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 033ACC001B0 for ; Wed, 19 Jul 2023 06:32:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229905AbjGSGcS (ORCPT ); Wed, 19 Jul 2023 02:32:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54980 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229831AbjGSGcQ (ORCPT ); Wed, 19 Jul 2023 02:32:16 -0400 Received: from mail-ot1-x32a.google.com (mail-ot1-x32a.google.com [IPv6:2607:f8b0:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B7771FC4 for ; Tue, 18 Jul 2023 23:32:14 -0700 (PDT) Received: by mail-ot1-x32a.google.com with SMTP id 46e09a7af769-6b9edef7993so486827a34.2 for ; Tue, 18 Jul 2023 23:32:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1689748334; x=1692340334; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=c9KrLLP8cL1uPsjJ1nSTy5SK2yTBHa/947mlcAdb160=; b=OdMNMSpEfv/yH1YzdMwSElZuj3ZFDDe2Uvr+0uT/C9mKCgI3PnkaDphepFbwXZGaEh 4veUsr3yq4av+3Kyq+YmVd8InvdEWYYmEbxxSbxVZpDlbA8mF7IUCkYe0beFK37O129D HwZepvEjoG0zFUPtNuvTTJNeKyeFZNy5V0aLxZXX4omIC3Pi/jf6NyTqsEStkdHwzKpp KLIRLmMK5x4fsT0nFh8BTFe6u7ptjPcC8XeOO6h7Zj9FF0SK+Hg5C4Ln1YpMWgWaPOIQ DcqIgGRwYzCSxddeZapFOS1ZpehwxS41A/L2zcFcH55bH7WPxxoB8TARBVQ51D1vrgax vtSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689748334; x=1692340334; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=c9KrLLP8cL1uPsjJ1nSTy5SK2yTBHa/947mlcAdb160=; b=Be0DXbvYyI+gb5RPqZGdZdeXggPSAN2vIgrUY+3NVCX1zSQ5nsx0eb0oYSg50kbo4S JCQxoU+1wWoqnfyxSykgdKSiKaAwhosBydw+jKz7QkNXyUFJvCgbfPolL8aXZu4GkuoW iR7uiOQjqXyuxJ+kuMH57ph9r/nZjkB9um9EWT0xlKTINbEjnlAE8ln0oM23mR0+tobd xLT65ka45n3tyaZ6jt6eCMpUHcvVwWXTfQh48cW4nq/+G9W/hWsLJ/lZH5I6faauwQum xumoMnTxMY6Pu5pieooDc+OrqegP1Kd/0RdgNWkCLzobjDlS7+eLYEZ/fHgu/3TX3T2J H9Qw== X-Gm-Message-State: ABy/qLYDPuBUXHS6t+6+YnZamWhWV7++B4TWscReRfMVw7ITvNWZGg6t HxgNgKASwOiHNTGmu6VY9EzQz0SaxefHRpSZygng7w== X-Google-Smtp-Source: APBJJlG7Hnr+DLSYxVj/kGW324BYuM9R7IW3z2osuMAejNGZ153KuMIBDUA2MT+Nc81tM5Yh8hK+Hg== X-Received: by 2002:a05:6830:1110:b0:6b8:90cd:47b5 with SMTP id w16-20020a056830111000b006b890cd47b5mr5139616otq.7.1689748333811; Tue, 18 Jul 2023 23:32:13 -0700 (PDT) Received: from PXLDJ45XCM.bytedance.net ([139.177.225.226]) by smtp.gmail.com with ESMTPSA id p12-20020a631e4c000000b005348af1b84csm2701678pgm.74.2023.07.18.23.32.10 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 18 Jul 2023 23:32:12 -0700 (PDT) From: Muchun Song To: mike.kravetz@oracle.com, muchun.song@linux.dev, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song Subject: [PATCH] mm: hugetlb_vmemmap: use PageCompound() instead of PageReserved() Date: Wed, 19 Jul 2023 14:31:31 +0800 Message-Id: <20230719063132.37676-1-songmuchun@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The ckeck of PageReserved() is easy to be broken in the future, PageCompoun= d() is more stable to check if the page should be split. Signed-off-by: Muchun Song --- mm/hugetlb_vmemmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 4b9734777f69..8068fe890f52 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -73,8 +73,10 @@ static int split_vmemmap_huge_pmd(pmd_t *pmd, unsigned l= ong start) * be treated as indepdenent small pages (as they can be freed * individually). */ - if (!PageReserved(head)) + if (PageCompound(head)) { + VM_BUG_ON(compound_order(head) !=3D get_order(PMD_SIZE)); split_page(head, get_order(PMD_SIZE)); + } =20 /* Make pte visible before pmd. See comment in pmd_install(). */ smp_wmb(); --=20 2.11.0