From mboxrd@z Thu Jan 1 00:00:00 1970 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 A1023C46467 for ; Tue, 10 Jan 2023 06:45:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229505AbjAJGp1 convert rfc822-to-8bit (ORCPT ); Tue, 10 Jan 2023 01:45:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56750 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229660AbjAJGpY (ORCPT ); Tue, 10 Jan 2023 01:45:24 -0500 Received: from ex01.ufhost.com (ex01.ufhost.com [61.152.239.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CED1CE26 for ; Mon, 9 Jan 2023 22:45:21 -0800 (PST) Received: from EXMBX166.cuchost.com (unknown [175.102.18.54]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "EXMBX166", Issuer "EXMBX166" (not verified)) by ex01.ufhost.com (Postfix) with ESMTP id 8A8A224E217; Tue, 10 Jan 2023 14:45:19 +0800 (CST) Received: from EXMBX162.cuchost.com (172.16.6.72) by EXMBX166.cuchost.com (172.16.6.76) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Tue, 10 Jan 2023 14:45:19 +0800 Received: from EXMBX066.cuchost.com (172.16.7.66) by EXMBX162.cuchost.com (172.16.6.72) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Tue, 10 Jan 2023 14:45:19 +0800 Received: from EXMBX066.cuchost.com ([fe80::5947:9245:907e:339f]) by EXMBX066.cuchost.com ([fe80::5947:9245:907e:339f%17]) with mapi id 15.00.1497.044; Tue, 10 Jan 2023 14:45:19 +0800 From: JeeHeng Sia To: Andrew Jones CC: "paul.walmsley@sifive.com" , "palmer@dabbelt.com" , "aou@eecs.berkeley.edu" , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Leyfoon Tan , Mason Huo Subject: RE: [PATCH v2 2/3] RISC-V: mm: Enable huge page support to kernel_page_present() function Thread-Topic: [PATCH v2 2/3] RISC-V: mm: Enable huge page support to kernel_page_present() function Thread-Index: AQHZI/MEyk4BWxsDWk+SJDmuy1TBsK6VpAGAgAGQfoA= Date: Tue, 10 Jan 2023 06:45:19 +0000 Message-ID: <62163664add9493db394c8ca45b73ce2@EXMBX066.cuchost.com> References: <20230109062407.3235-1-jeeheng.sia@starfivetech.com> <20230109062407.3235-3-jeeheng.sia@starfivetech.com> <20230109144525.4xgnpeb6zcyyvx4j@orel> In-Reply-To: <20230109144525.4xgnpeb6zcyyvx4j@orel> Accept-Language: en-US, zh-CN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [60.49.128.133] x-yovoleruleagent: yovoleflag Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Andrew Jones > Sent: Monday, 9 January, 2023 10:45 PM > To: JeeHeng Sia > Cc: paul.walmsley@sifive.com; palmer@dabbelt.com; > aou@eecs.berkeley.edu; linux-riscv@lists.infradead.org; linux- > kernel@vger.kernel.org; Leyfoon Tan ; > Mason Huo > Subject: Re: [PATCH v2 2/3] RISC-V: mm: Enable huge page support to > kernel_page_present() function > > On Mon, Jan 09, 2023 at 02:24:06PM +0800, Sia Jee Heng wrote: > > Currently kernel_page_present() function doesn't support huge page > > detection causes the function to mistakenly return false to the > > hibernation core. > > > > Add huge page detection to the function to solve the problem. > > > > Signed-off-by: Sia Jee Heng > > Reviewed-by: Ley Foon Tan > > Reviewed-by: Mason Huo > > --- > > arch/riscv/mm/pageattr.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c > > index 86c56616e5de..73fdec8c0a72 100644 > > --- a/arch/riscv/mm/pageattr.c > > +++ b/arch/riscv/mm/pageattr.c > > @@ -221,14 +221,20 @@ bool kernel_page_present(struct page *page) > > p4d = p4d_offset(pgd, addr); > > if (!p4d_present(*p4d)) > > return false; > > + if (p4d_leaf(*pud)) > ^ p4d > > I guess you got lucky with the stack garbage in your testing. You are right. But the reason it is added here is because kernel page table walk is checking for the p4d_leaf as well. For example: walk_p4d_range() in the mm/pagewalk.c. So, I just trying to make it consistent to the Kernel page table walk mechanism. Should I remove it? > > > + return true; > > > > pud = pud_offset(p4d, addr); > > if (!pud_present(*pud)) > > return false; > > + if (pud_leaf(*pud)) > > + return true; > > > > pmd = pmd_offset(pud, addr); > > if (!pmd_present(*pmd)) > > return false; > > + if (pmd_leaf(*pmd)) > > + return true; > > > > pte = pte_offset_kernel(pmd, addr); > > return pte_present(*pte); > > -- > > 2.34.1 > > > > Thanks, > drew