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 X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DDA22C433E0 for ; Wed, 12 Aug 2020 13:20:30 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D87F20656 for ; Wed, 12 Aug 2020 13:20:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D87F20656 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4BRVgc23CWzDqb9 for ; Wed, 12 Aug 2020 23:20:28 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=anshuman.khandual@arm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=arm.com Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4BRTwZ25mYzDqWq for ; Wed, 12 Aug 2020 22:46:37 +1000 (AEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BE4FD31B; Wed, 12 Aug 2020 05:46:35 -0700 (PDT) Received: from [10.163.66.87] (unknown [10.163.66.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DF5973F70D; Wed, 12 Aug 2020 05:46:33 -0700 (PDT) Subject: Re: [PATCH 08/16] debug_vm_pgtable/set_pmd: Don't use set_pmd_at to update an existing pmd entry To: "Aneesh Kumar K.V" , linux-mm@kvack.org, akpm@linux-foundation.org References: <20200812063358.369514-1-aneesh.kumar@linux.ibm.com> <20200812063358.369514-8-aneesh.kumar@linux.ibm.com> From: Anshuman Khandual Message-ID: Date: Wed, 12 Aug 2020 18:16:04 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200812063358.369514-8-aneesh.kumar@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 08/12/2020 12:03 PM, Aneesh Kumar K.V wrote: > set_pmd_at() should not be used to set a pte entry at locations that > already holds a valid pte entry. Architectures like ppc64 don't do TLB > invalidate in set_pmd_at() and hence expect it to be used to set locations > that are not a valid PTE. > > Signed-off-by: Aneesh Kumar K.V > --- > mm/debug_vm_pgtable.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index cd609a212dd4..60bf876081b8 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -164,8 +164,6 @@ static void __init pmd_advanced_tests(struct mm_struct *mm, > pmd = READ_ONCE(*pmdp); > WARN_ON(pmd_write(pmd)); > > - pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); > - set_pmd_at(mm, vaddr, pmdp, pmd); > pmdp_huge_get_and_clear(mm, vaddr, pmdp); > pmd = READ_ONCE(*pmdp); > WARN_ON(!pmd_none(pmd)); > @@ -180,12 +178,11 @@ static void __init pmd_advanced_tests(struct mm_struct *mm, > pmd = READ_ONCE(*pmdp); > WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd))); > > - pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); > - set_pmd_at(mm, vaddr, pmdp, pmd); > pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1); > pmd = READ_ONCE(*pmdp); > WARN_ON(!pmd_none(pmd)); > > + pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); > pmd = pmd_mkyoung(pmd); > set_pmd_at(mm, vaddr, pmdp, pmd); > pmdp_test_and_clear_young(vma, vaddr, pmdp); > Very similar to [PATCH 3/16] wrt set_pte_at(), please fold it.