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 3B209C63797 for ; Thu, 22 Jul 2021 05:38:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BCD061264 for ; Thu, 22 Jul 2021 05:38:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229971AbhGVE6H (ORCPT ); Thu, 22 Jul 2021 00:58:07 -0400 Received: from foss.arm.com ([217.140.110.172]:44114 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229540AbhGVE6D (ORCPT ); Thu, 22 Jul 2021 00:58:03 -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 B081AD6E; Wed, 21 Jul 2021 22:38:38 -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 3FCBC3F66F; Wed, 21 Jul 2021 22:38:36 -0700 (PDT) Subject: Re: [PATCH v3 09/12] mm/debug_vm_pgtable: Use struct pgtable_debug_args in PUD 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> <20210719130613.334901-10-gshan@redhat.com> From: Anshuman Khandual Message-ID: <8997bf56-ff67-060d-c25b-91e11f31e88a@arm.com> Date: Thu, 22 Jul 2021 11:09:25 +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: <20210719130613.334901-10-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 PUD modifying tests. The allocated > huge page is used when set_pud_at() is used. The corresponding tests > are skipped if the huge page doesn't exist. Besides, the following unused > variables in debug_vm_pgtable() are dropped: @prot, @paddr, @pud_aligned. Please dont drop @prot, @paddr, @pud_aligned just yet. > > Signed-off-by: Gavin Shan > --- > mm/debug_vm_pgtable.c | 130 ++++++++++++++++-------------------------- > 1 file changed, 50 insertions(+), 80 deletions(-) > > diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c > index cec3cbf99a6b..57b7ead0708b 100644 > --- a/mm/debug_vm_pgtable.c > +++ b/mm/debug_vm_pgtable.c > @@ -338,55 +338,55 @@ static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) > WARN_ON(!pud_bad(pud_mkhuge(pud))); > } > > -static void __init pud_advanced_tests(struct mm_struct *mm, > - struct vm_area_struct *vma, pud_t *pudp, > - unsigned long pfn, unsigned long vaddr, > - pgprot_t prot) > +static void __init pud_advanced_tests(struct pgtable_debug_args *args) > { > + unsigned long vaddr = (args->vaddr & HPAGE_PUD_MASK); > pud_t pud; > > if (!has_transparent_hugepage()) > return; > > pr_debug("Validating PUD advanced\n"); > - /* Align the address wrt HPAGE_PUD_SIZE */ > - vaddr &= HPAGE_PUD_MASK; Please just leave these unchanged. If has_transparent_hugepage() evaluates negative, it skips the masking operation. As mentioned earlier please avoid changing the test in any manner during these transition patches. > + if (args->pud_pfn == ULONG_MAX) { > + pr_debug("%s: Skipped\n", __func__); Just return. Please dont call out "Skipped". Applicable for all transition patches here. > + return; > + } > > - pud = pfn_pud(pfn, prot); > - set_pud_at(mm, vaddr, pudp, pud); > - pudp_set_wrprotect(mm, vaddr, pudp); > - pud = READ_ONCE(*pudp); > + pud = pfn_pud(args->pud_pfn, args->page_prot); > + set_pud_at(args->mm, vaddr, args->pudp, pud); > + pudp_set_wrprotect(args->mm, vaddr, args->pudp); > + pud = READ_ONCE(*(args->pudp)); Seems like an extra braces while de-referencing arg->pudp. Could these be dropped. Just READ_ONCE(*args->pudp). > WARN_ON(pud_write(pud)); > > #ifndef __PAGETABLE_PMD_FOLDED > - pudp_huge_get_and_clear(mm, vaddr, pudp); > - pud = READ_ONCE(*pudp); > + pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(!pud_none(pud)); > #endif /* __PAGETABLE_PMD_FOLDED */ > - pud = pfn_pud(pfn, prot); > + pud = pfn_pud(args->pud_pfn, args->page_prot); > pud = pud_wrprotect(pud); > pud = pud_mkclean(pud); > - set_pud_at(mm, vaddr, pudp, pud); > + set_pud_at(args->mm, vaddr, args->pudp, pud); > pud = pud_mkwrite(pud); > pud = pud_mkdirty(pud); > - pudp_set_access_flags(vma, vaddr, pudp, pud, 1); > - pud = READ_ONCE(*pudp); > + pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(!(pud_write(pud) && pud_dirty(pud))); > > #ifndef __PAGETABLE_PMD_FOLDED > - pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1); > - pud = READ_ONCE(*pudp); > + pudp_huge_get_and_clear_full(args->mm, vaddr, args->pudp, 1); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(!pud_none(pud)); > #endif /* __PAGETABLE_PMD_FOLDED */ > > - pud = pfn_pud(pfn, prot); > + pud = pfn_pud(args->pud_pfn, args->page_prot); > pud = pud_mkyoung(pud); > - set_pud_at(mm, vaddr, pudp, pud); > - pudp_test_and_clear_young(vma, vaddr, pudp); > - pud = READ_ONCE(*pudp); > + set_pud_at(args->mm, vaddr, args->pudp, pud); > + pudp_test_and_clear_young(args->vma, vaddr, args->pudp); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(pud_young(pud)); > > - pudp_huge_get_and_clear(mm, vaddr, pudp); > + pudp_huge_get_and_clear(args->mm, vaddr, args->pudp); > } > > static void __init pud_leaf_tests(struct pgtable_debug_args *args) > @@ -406,24 +406,14 @@ static void __init pud_leaf_tests(struct pgtable_debug_args *args) > } > #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ > static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } > -static void __init pud_advanced_tests(struct mm_struct *mm, > - struct vm_area_struct *vma, pud_t *pudp, > - unsigned long pfn, unsigned long vaddr, > - pgprot_t prot) > -{ > -} > +static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } > static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } > #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ > #else /* !CONFIG_TRANSPARENT_HUGEPAGE */ > static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { } > static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { } > static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { } > -static void __init pud_advanced_tests(struct mm_struct *mm, > - struct vm_area_struct *vma, pud_t *pudp, > - unsigned long pfn, unsigned long vaddr, > - pgprot_t prot) > -{ > -} > +static void __init pud_advanced_tests(struct pgtable_debug_args *args) { } > static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { } > static void __init pud_leaf_tests(struct pgtable_debug_args *args) { } > static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) { } > @@ -450,11 +440,11 @@ static void __init pmd_huge_tests(struct pgtable_debug_args *args) > WARN_ON(!pmd_none(pmd)); > } > > -static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) > +static void __init pud_huge_tests(struct pgtable_debug_args *args) > { > pud_t pud; > > - if (!arch_vmap_pud_supported(prot)) > + if (!arch_vmap_pud_supported(args->page_prot)) > return; > > pr_debug("Validating PUD huge\n"); > @@ -462,15 +452,16 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) > * X86 defined pud_set_huge() verifies that the given > * PUD is not a populated non-leaf entry. > */ > - WRITE_ONCE(*pudp, __pud(0)); > - WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot)); > - WARN_ON(!pud_clear_huge(pudp)); > - pud = READ_ONCE(*pudp); > + WRITE_ONCE(*(args->pudp), __pud(0)); > + WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), > + args->page_prot)); Please dont break the line, we could go upto 100 width. Please do the same for the entire series. Improves the readability. > + WARN_ON(!pud_clear_huge(args->pudp)); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(!pud_none(pud)); > } > #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ > static void __init pmd_huge_tests(struct pgtable_debug_args *args) { } > -static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { } > +static void __init pud_huge_tests(struct pgtable_debug_args *args) { } > #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ > > static void __init p4d_basic_tests(void) > @@ -492,27 +483,26 @@ static void __init pgd_basic_tests(void) > } > > #ifndef __PAGETABLE_PUD_FOLDED > -static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) > +static void __init pud_clear_tests(struct pgtable_debug_args *args) > { > - pud_t pud = READ_ONCE(*pudp); > + pud_t pud = READ_ONCE(*(args->pudp)); > > - if (mm_pmd_folded(mm)) > + if (mm_pmd_folded(args->mm)) > return; > > pr_debug("Validating PUD clear\n"); > pud = __pud(pud_val(pud) | RANDOM_ORVALUE); > - WRITE_ONCE(*pudp, pud); > - pud_clear(pudp); > - pud = READ_ONCE(*pudp); > + WRITE_ONCE(*(args->pudp), pud); > + pud_clear(args->pudp); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(!pud_none(pud)); > } > > -static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, > - pmd_t *pmdp) > +static void __init pud_populate_tests(struct pgtable_debug_args *args) > { > pud_t pud; > > - if (mm_pmd_folded(mm)) > + if (mm_pmd_folded(args->mm)) > return; > > pr_debug("Validating PUD populate\n"); > @@ -520,16 +510,13 @@ static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, > * This entry points to next level page table page. > * Hence this must not qualify as pud_bad(). > */ > - pud_populate(mm, pudp, pmdp); > - pud = READ_ONCE(*pudp); > + pud_populate(args->mm, args->pudp, args->start_pmdp); > + pud = READ_ONCE(*(args->pudp)); > WARN_ON(pud_bad(pud)); > } > #else /* !__PAGETABLE_PUD_FOLDED */ > -static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { } > -static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp, > - pmd_t *pmdp) > -{ > -} > +static void __init pud_clear_tests(struct pgtable_debug_args *args) { } > +static void __init pud_populate_tests(struct pgtable_debug_args *args) { } > #endif /* PAGETABLE_PUD_FOLDED */ > > #ifndef __PAGETABLE_P4D_FOLDED > @@ -1152,10 +1139,7 @@ static int __init debug_vm_pgtable(void) > pud_t *pudp, *saved_pudp; > pmd_t *pmdp, *saved_pmdp, pmd; > pgtable_t saved_ptep; > - pgprot_t prot; > - phys_addr_t paddr; > unsigned long vaddr; > - unsigned long pud_aligned; > spinlock_t *ptl = NULL; > int idx, ret; > > @@ -1164,7 +1148,6 @@ static int __init debug_vm_pgtable(void) > if (ret) > return ret; > > - prot = vm_get_page_prot(VMFLAGS); Please dont drop these just yet and wait until [PATCH 11/12]. > vaddr = get_random_vaddr(); > mm = mm_alloc(); > if (!mm) { > @@ -1178,19 +1161,6 @@ static int __init debug_vm_pgtable(void) > return 1; > } > > - /* > - * PFN for mapping at PTE level is determined from a standard kernel > - * text symbol. But pfns for higher page table levels are derived by > - * masking lower bits of this real pfn. These derived pfns might not > - * exist on the platform but that does not really matter as pfn_pxx() > - * helpers will still create appropriate entries for the test. This > - * helps avoid large memory block allocations to be used for mapping > - * at higher page table levels. > - */ Please move this comment as is to the right place inside init_args() in the first patch itself. If possible all comments should be moved during the first patch and just the code remains till [PATCH 11/12]. > - paddr = __pa_symbol(&start_kernel); > - > - pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; > - Please dont drop these just yet and wait until [PATCH 11/12]. > pgdp = pgd_offset(mm, vaddr); > p4dp = p4d_alloc(mm, pgdp, vaddr); > pudp = pud_alloc(mm, p4dp, vaddr); > @@ -1282,11 +1252,11 @@ static int __init debug_vm_pgtable(void) > pmd_populate_tests(&args); > spin_unlock(ptl); > > - ptl = pud_lock(mm, pudp); > - pud_clear_tests(mm, pudp); > - pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot); > - pud_huge_tests(pudp, pud_aligned, prot); > - pud_populate_tests(mm, pudp, saved_pmdp); > + ptl = pud_lock(args.mm, args.pudp); > + pud_clear_tests(&args); > + pud_advanced_tests(&args); > + pud_huge_tests(&args); > + pud_populate_tests(&args); > spin_unlock(ptl); > > spin_lock(&mm->page_table_lock); >