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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 92937C63793 for ; Thu, 22 Jul 2021 05:08:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C60161264 for ; Thu, 22 Jul 2021 05:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229731AbhGVE1r (ORCPT ); Thu, 22 Jul 2021 00:27:47 -0400 Received: from foss.arm.com ([217.140.110.172]:43678 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhGVE1q (ORCPT ); Thu, 22 Jul 2021 00:27:46 -0400 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 1D413D6E; Wed, 21 Jul 2021 22:08:22 -0700 (PDT) Received: from [10.163.65.134] (unknown [10.163.65.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 675F33F66F; Wed, 21 Jul 2021 22:08:19 -0700 (PDT) From: Anshuman Khandual Subject: Re: [PATCH v3 10/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PGD and P4D modifying tests To: Gavin Shan , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, chuhu@redhat.com, shan.gavin@gmail.com References: <20210719130613.334901-1-gshan@redhat.com> <20210719130613.334901-11-gshan@redhat.com> Message-ID: Date: Thu, 22 Jul 2021 10:39:08 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210719130613.334901-11-gshan@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/19/21 6:36 PM, Gavin Shan wrote: > This uses struct pgtable_debug_args in PGD/P4D modifying tests. No > allocated huge page is used in these tests. Besides, the unused > variable @saved_p4dp and @saved_pudp are dropped. Please dont drop @saved_p4dp and @saved_pudp just yet. > > Signed-off-by: Gavin Shan > --- > mm/debug_vm_pgtable.c | 86 +++++++++++++++++++------------------------ > 1 file changed, 38 insertions(+), 48 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index 57b7ead0708b..5ebacc940b68 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -520,27 +520,26 @@ static void __init pud_populate_tests(struct pgtable_debug_args *args) { } > #endif /* PAGETABLE_PUD_FOLDED */ > > #ifndef __PAGETABLE_P4D_FOLDED > -static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) > +static void __init p4d_clear_tests(struct pgtable_debug_args *args) > { > - p4d_t p4d = READ_ONCE(*p4dp); > + p4d_t p4d = READ_ONCE(*(args->p4dp)); > > - if (mm_pud_folded(mm)) > + if (mm_pud_folded(args->mm)) > return; > > pr_debug("Validating P4D clear\n"); > p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE); > - WRITE_ONCE(*p4dp, p4d); > - p4d_clear(p4dp); > - p4d = READ_ONCE(*p4dp); > + WRITE_ONCE(*(args->p4dp), p4d); > + p4d_clear(args->p4dp); > + p4d = READ_ONCE(*(args->p4dp)); > WARN_ON(!p4d_none(p4d)); > } > > -static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, > - pud_t *pudp) > +static void __init p4d_populate_tests(struct pgtable_debug_args *args) > { > p4d_t p4d; > > - if (mm_pud_folded(mm)) > + if (mm_pud_folded(args->mm)) > return; > > pr_debug("Validating P4D populate\n"); > @@ -548,34 +547,33 @@ static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, > * This entry points to next level page table page. > * Hence this must not qualify as p4d_bad(). > */ > - pud_clear(pudp); > - p4d_clear(p4dp); > - p4d_populate(mm, p4dp, pudp); > - p4d = READ_ONCE(*p4dp); > + pud_clear(args->pudp); > + p4d_clear(args->p4dp); > + p4d_populate(args->mm, args->p4dp, args->start_pudp); > + p4d = READ_ONCE(*(args->p4dp)); > WARN_ON(p4d_bad(p4d)); > } > > -static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) > +static void __init pgd_clear_tests(struct pgtable_debug_args *args) > { > - pgd_t pgd = READ_ONCE(*pgdp); > + pgd_t pgd = READ_ONCE(*(args->pgdp)); > > - if (mm_p4d_folded(mm)) > + if (mm_p4d_folded(args->mm)) > return; > > pr_debug("Validating PGD clear\n"); > pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE); > - WRITE_ONCE(*pgdp, pgd); > - pgd_clear(pgdp); > - pgd = READ_ONCE(*pgdp); > + WRITE_ONCE(*(args->pgdp), pgd); > + pgd_clear(args->pgdp); > + pgd = READ_ONCE(*(args->pgdp)); > WARN_ON(!pgd_none(pgd)); > } > > -static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, > - p4d_t *p4dp) > +static void __init pgd_populate_tests(struct pgtable_debug_args *args) > { > pgd_t pgd; > > - if (mm_p4d_folded(mm)) > + if (mm_p4d_folded(args->mm)) > return; > > pr_debug("Validating PGD populate\n"); > @@ -583,23 +581,17 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, > * This entry points to next level page table page. > * Hence this must not qualify as pgd_bad(). > */ > - p4d_clear(p4dp); > - pgd_clear(pgdp); > - pgd_populate(mm, pgdp, p4dp); > - pgd = READ_ONCE(*pgdp); > + p4d_clear(args->p4dp); > + pgd_clear(args->pgdp); > + pgd_populate(args->mm, args->pgdp, args->start_p4dp); > + pgd = READ_ONCE(*(args->pgdp)); > WARN_ON(pgd_bad(pgd)); > } > #else /* !__PAGETABLE_P4D_FOLDED */ > -static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { } > -static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { } > -static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp, > - pud_t *pudp) > -{ > -} > -static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, > - p4d_t *p4dp) > -{ > -} > +static void __init p4d_clear_tests(struct pgtable_debug_args *args) { } > +static void __init pgd_clear_tests(struct pgtable_debug_args *args) { } > +static void __init p4d_populate_tests(struct pgtable_debug_args *args) { } > +static void __init pgd_populate_tests(struct pgtable_debug_args *args) { } > #endif /* PAGETABLE_P4D_FOLDED */ > > static void __init pte_clear_tests(struct pgtable_debug_args *args) > @@ -1135,8 +1127,8 @@ static int __init debug_vm_pgtable(void) > struct vm_area_struct *vma; > struct mm_struct *mm; > pgd_t *pgdp; > - p4d_t *p4dp, *saved_p4dp; > - pud_t *pudp, *saved_pudp; > + p4d_t *p4dp; > + pud_t *pudp; > pmd_t *pmdp, *saved_pmdp, pmd; > pgtable_t saved_ptep; > unsigned long vaddr; > @@ -1180,8 +1172,6 @@ static int __init debug_vm_pgtable(void) > * page table pages. > */ > pmd = READ_ONCE(*pmdp); > - saved_p4dp = p4d_offset(pgdp, 0UL); > - saved_pudp = pud_offset(p4dp, 0UL); > saved_pmdp = pmd_offset(pudp, 0UL); > saved_ptep = pmd_pgtable(pmd); > > @@ -1259,15 +1249,15 @@ static int __init debug_vm_pgtable(void) > pud_populate_tests(&args); > spin_unlock(ptl); > > - spin_lock(&mm->page_table_lock); > - p4d_clear_tests(mm, p4dp); > - pgd_clear_tests(mm, pgdp); > - p4d_populate_tests(mm, p4dp, saved_pudp); > - pgd_populate_tests(mm, pgdp, saved_p4dp); > - spin_unlock(&mm->page_table_lock); > + spin_lock(&(args.mm->page_table_lock)); > + p4d_clear_tests(&args); > + pgd_clear_tests(&args); > + p4d_populate_tests(&args); > + pgd_populate_tests(&args); > + spin_unlock(&(args.mm->page_table_lock)); > > - p4d_free(mm, saved_p4dp); > - pud_free(mm, saved_pudp); > + p4d_free(mm, p4d_offset(pgdp, 0UL)); > + pud_free(mm, pud_offset(p4dp, 0UL)); Please keep @saved_pudp and @saved_p4dp declaration, assignment and usage unchanged for now. Drop them only during [PATCH 11/12]. So in each patch like these, drop the elements only if there is an unused warning during build. There are two set of page table debug elements i.e old and new. The test is transitioning from old to new. Even after the transition is complete, the old elements are properly declared, initialized and freed up. Entire old set should be dropped only in [PATCH 11/12]. > pmd_free(mm, saved_pmdp); > pte_free(mm, saved_ptep); > >