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=-13.3 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=ham 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 AF6B4C433DF for ; Fri, 21 Aug 2020 08:20:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6FC502078D for ; Fri, 21 Aug 2020 08:20:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6FC502078D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E3BBE6B0036; Fri, 21 Aug 2020 04:20:56 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DEBBD6B0037; Fri, 21 Aug 2020 04:20:56 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D01C86B0055; Fri, 21 Aug 2020 04:20:56 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id BA0136B0036 for ; Fri, 21 Aug 2020 04:20:56 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 75ACD181AEF10 for ; Fri, 21 Aug 2020 08:20:56 +0000 (UTC) X-FDA: 77173880112.11.ring55_601437f27037 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 42FD2180F8B82 for ; Fri, 21 Aug 2020 08:20:56 +0000 (UTC) X-HE-Tag: ring55_601437f27037 X-Filterd-Recvd-Size: 5973 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Fri, 21 Aug 2020 08:20:55 +0000 (UTC) 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 051C230E; Fri, 21 Aug 2020 01:20:55 -0700 (PDT) Received: from [10.163.67.49] (unknown [10.163.67.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 46EDE3F66B; Fri, 21 Aug 2020 01:20:53 -0700 (PDT) Subject: Re: [PATCH v2 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry To: "Aneesh Kumar K.V" , Christophe Leroy , linux-mm@kvack.org, akpm@linux-foundation.org Cc: linuxppc-dev@lists.ozlabs.org References: <20200819130107.478414-1-aneesh.kumar@linux.ibm.com> <20200819130107.478414-8-aneesh.kumar@linux.ibm.com> <3d966519-0a6b-3ccb-fd21-b7f06c8e4df7@linux.ibm.com> From: Anshuman Khandual Message-ID: <5a7f6dd1-eb13-d942-6fab-80265cd421fc@arm.com> Date: Fri, 21 Aug 2020 13:50:22 +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: <3d966519-0a6b-3ccb-fd21-b7f06c8e4df7@linux.ibm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Rspamd-Queue-Id: 42FD2180F8B82 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 08/21/2020 12:44 PM, Aneesh Kumar K.V wrote: > On 8/20/20 8:02 PM, Christophe Leroy wrote: >> >> >> Le 19/08/2020 =C3=A0 15:01, Aneesh Kumar K.V a =C3=A9crit=C2=A0: >>> set_pte_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 TL= B >>> invalidate in set_pte_at() and hence expect it to be used to set loca= tions >>> that are not a valid PTE. >>> >>> Signed-off-by: Aneesh Kumar K.V >>> --- >>> =C2=A0 mm/debug_vm_pgtable.c | 35 +++++++++++++++-------------------- >>> =C2=A0 1 file changed, 15 insertions(+), 20 deletions(-) >>> >>> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c >>> index 76f4c713e5a3..9c7e2c9cfc76 100644 >>> --- a/mm/debug_vm_pgtable.c >>> +++ b/mm/debug_vm_pgtable.c >>> @@ -74,15 +74,18 @@ static void __init pte_advanced_tests(struct mm_s= truct *mm, >>> =C2=A0 { >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte_t pte =3D pfn_pte(pfn, prot); >>> +=C2=A0=C2=A0=C2=A0 /* >>> +=C2=A0=C2=A0=C2=A0=C2=A0 * Architectures optimize set_pte_at by avoi= ding TLB flush. >>> +=C2=A0=C2=A0=C2=A0=C2=A0 * This requires set_pte_at to be not used t= o update an >>> +=C2=A0=C2=A0=C2=A0=C2=A0 * existing pte entry. Clear pte before we d= o set_pte_at >>> +=C2=A0=C2=A0=C2=A0=C2=A0 */ >>> + >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pr_debug("Validating PTE advanced\n"); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D pfn_pte(pfn, prot); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 set_pte_at(mm, vaddr, ptep, pte); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ptep_set_wrprotect(mm, vaddr, ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D ptep_get(ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(pte_write(pte)); >>> - >>> -=C2=A0=C2=A0=C2=A0 pte =3D pfn_pte(pfn, prot); >>> -=C2=A0=C2=A0=C2=A0 set_pte_at(mm, vaddr, ptep, pte); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ptep_get_and_clear(mm, vaddr, ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D ptep_get(ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!pte_none(pte)); >>> @@ -96,13 +99,11 @@ static void __init pte_advanced_tests(struct mm_s= truct *mm, >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ptep_set_access_flags(vma, vaddr, ptep= , pte, 1); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D ptep_get(ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!(pte_write(pte) && pte_dirty(= pte))); >>> - >>> -=C2=A0=C2=A0=C2=A0 pte =3D pfn_pte(pfn, prot); >>> -=C2=A0=C2=A0=C2=A0 set_pte_at(mm, vaddr, ptep, pte); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ptep_get_and_clear_full(mm, vaddr, pte= p, 1); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D ptep_get(ptep); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!pte_none(pte)); >>> +=C2=A0=C2=A0=C2=A0 pte =3D pfn_pte(pfn, prot); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pte =3D pte_mkyoung(pte); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 set_pte_at(mm, vaddr, ptep, pte); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ptep_test_and_clear_young(vma, vaddr, = ptep); >>> @@ -164,9 +165,6 @@ static void __init pmd_advanced_tests(struct mm_s= truct *mm, >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmdp_set_wrprotect(mm, vaddr, pmdp); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmd =3D READ_ONCE(*pmdp); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(pmd_write(pmd)); >>> - >>> -=C2=A0=C2=A0=C2=A0 pmd =3D pmd_mkhuge(pfn_pmd(pfn, prot)); >>> -=C2=A0=C2=A0=C2=A0 set_pmd_at(mm, vaddr, pmdp, pmd); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmdp_huge_get_and_clear(mm, vaddr, pmd= p); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmd =3D READ_ONCE(*pmdp); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!pmd_none(pmd)); >>> @@ -180,13 +178,11 @@ static void __init pmd_advanced_tests(struct mm= _struct *mm, >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmdp_set_access_flags(vma, vaddr, pmdp= , pmd, 1); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmd =3D READ_ONCE(*pmdp); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!(pmd_write(pmd) && pmd_dirty(= pmd))); >>> - >>> -=C2=A0=C2=A0=C2=A0 pmd =3D pmd_mkhuge(pfn_pmd(pfn, prot)); >>> -=C2=A0=C2=A0=C2=A0 set_pmd_at(mm, vaddr, pmdp, pmd); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmdp_huge_get_and_clear_full(vma, vadd= r, pmdp, 1); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmd =3D READ_ONCE(*pmdp); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(!pmd_none(pmd)); >>> +=C2=A0=C2=A0=C2=A0 pmd =3D pmd_mkhuge(pfn_pmd(pfn, prot)); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmd =3D pmd_mkyoung(pmd); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 set_pmd_at(mm, vaddr, pmdp, pmd); >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 pmdp_test_and_clear_young(vma, vaddr, = pmdp); >>> @@ -283,18 +279,10 @@ static void __init pud_advanced_tests(struct mm= _struct *mm, >>> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 WARN_ON(pud_write(pud)); >>> =C2=A0 #ifndef __PAGETABLE_PMD_FOLDED >> >> Same as below, once set_put_at() is gone, I don't think this #ifndef _= _PAGETABLE_PMD_FOLDED is still need, should be possible to replace by 'if= (mm_pmd_folded())' >=20 > I would skip that change in this series because I still haven't worked = out what it means to have FOLDED PMD with CONFIG_HAVE_ARCH_TRANSPARENT_HU= GEPAGE_PUD. >=20 >=20 > We should probably push that as a cleanup later and somebody who can te= st that config can do that? Currently i can't boot ppc64 with DBUG_VM_PGT= ABLE enabled on ppc64 because it is all buggy w.r.t rules. Agreed. I think its OK not address these changes/improvements in this par= ticular series which is trying to modify the test to make it run on ppc64 platfor= m. I will probably look into that later.