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Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v3 02/12] mm/debug_vm_pgtable: Use struct
 pgtable_debug_args in basic tests
To:     Anshuman Khandual <anshuman.khandual@arm.com>, 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>
 <20210719130613.334901-3-gshan@redhat.com>
 <20c7be76-661b-6e75-3721-7b577fb4e05d@arm.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <c71684f7-46af-ce26-4301-4d2b1387e4df@redhat.com>
Date:   Wed, 21 Jul 2021 21:57:37 +1000
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Hi Anshuman,

On 7/21/21 3:57 PM, Anshuman Khandual wrote:
> On 7/19/21 6:36 PM, Gavin Shan wrote:
>> This uses struct pgtable_debug_args in the basic test functions. There
>> are more cleanups applied:
>>
>>     * Move hugetlb_basic_tests() so that the basic tests are treated
>>       as a bundle.
> 
> Please dont move this test as it is placed near to the THP functions.
> Also please don't club any non-related changes here while converting
> various tests into this new arg structure.
> 

Yes. I won't move hugetlb_basic_tests() around in v4.

>>
>>     * Drop parameters to {pgd, p4d}_basic_tests() as they're never
>>       used.
> 
> Right, they are not getting used right now. But then it might be just
> better to replace them with this new structure in order not to do any
> unrelated changes.
> 

Sure. I will pass &args to these two functions in v4, even they are
not used. Hopefully, I understand your comments correctly.


>>
>>     * Drop unused variables @{pgd, p4d}_aligned in debug_vm_pgtable().
>>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>>   mm/debug_vm_pgtable.c | 51 ++++++++++++++++++++-----------------------
>>   1 file changed, 24 insertions(+), 27 deletions(-)
>>
>> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
>> index ea153ff40d23..5f79d725f8d8 100644
>> --- a/mm/debug_vm_pgtable.c
>> +++ b/mm/debug_vm_pgtable.c
>> @@ -88,10 +88,10 @@ struct pgtable_debug_args {
>>   	unsigned long		fixed_pte_pfn;
>>   };
>>   
>> -static void __init pte_basic_tests(unsigned long pfn, int idx)
>> +static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
>>   {
>>   	pgprot_t prot = protection_map[idx];
>> -	pte_t pte = pfn_pte(pfn, prot);
>> +	pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);
>>   	unsigned long val = idx, *ptr = &val;
>>   
>>   	pr_debug("Validating PTE basic (%pGv)\n", ptr);
>> @@ -173,7 +173,7 @@ static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
>>   }
>>   
>>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> -static void __init pmd_basic_tests(unsigned long pfn, int idx)
>> +static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
>>   {
>>   	pgprot_t prot = protection_map[idx];
>>   	unsigned long val = idx, *ptr = &val;
>> @@ -183,7 +183,7 @@ static void __init pmd_basic_tests(unsigned long pfn, int idx)
>>   		return;
>>   
>>   	pr_debug("Validating PMD basic (%pGv)\n", ptr);
>> -	pmd = pfn_pmd(pfn, prot);
>> +	pmd = pfn_pmd(args->fixed_pmd_pfn, prot);
>>   
>>   	/*
>>   	 * This test needs to be executed after the given page table entry
>> @@ -295,7 +295,7 @@ static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
>>   }
>>   
>>   #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
>> -static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx)
>> +static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
>>   {
>>   	pgprot_t prot = protection_map[idx];
>>   	unsigned long val = idx, *ptr = &val;
>> @@ -305,7 +305,7 @@ static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int
>>   		return;
>>   
>>   	pr_debug("Validating PUD basic (%pGv)\n", ptr);
>> -	pud = pfn_pud(pfn, prot);
>> +	pud = pfn_pud(args->fixed_pud_pfn, prot);
>>   
>>   	/*
>>   	 * This test needs to be executed after the given page table entry
>> @@ -326,7 +326,7 @@ static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int
>>   	WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
>>   	WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
>>   
>> -	if (mm_pmd_folded(mm))
>> +	if (mm_pmd_folded(args->mm))
>>   		return;
>>   
>>   	/*
>> @@ -403,7 +403,7 @@ static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
>>   	WARN_ON(!pud_leaf(pud));
>>   }
>>   #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
>> -static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
>> +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,
>> @@ -413,8 +413,8 @@ static void __init pud_advanced_tests(struct mm_struct *mm,
>>   static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
>>   #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
>>   #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
>> -static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
>> -static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
>> +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 mm_struct *mm,
>>   				      struct vm_area_struct *vma, pmd_t *pmdp,
>>   				      unsigned long pfn, unsigned long vaddr,
>> @@ -475,7 +475,7 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
>>   static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
>>   #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
>>   
>> -static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
>> +static void __init p4d_basic_tests(void)
>>   {
>>   	p4d_t p4d;
>>   
>> @@ -484,7 +484,7 @@ static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
>>   	WARN_ON(!p4d_same(p4d, p4d));
>>   }
>>   
>> -static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
>> +static void __init pgd_basic_tests(void)
>>   {
>>   	pgd_t pgd;
>>   
>> @@ -889,7 +889,7 @@ static void __init swap_migration_tests(void)
>>   }
>>   
>>   #ifdef CONFIG_HUGETLB_PAGE
>> -static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
>> +static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
>>   {
>>   	struct page *page;
>>   	pte_t pte;
>> @@ -899,21 +899,21 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
>>   	 * Accessing the page associated with the pfn is safe here,
>>   	 * as it was previously derived from a real kernel symbol.
>>   	 */
>> -	page = pfn_to_page(pfn);
>> -	pte = mk_huge_pte(page, prot);
>> +	page = pfn_to_page(args->fixed_pmd_pfn);
>> +	pte = mk_huge_pte(page, args->page_prot);
>>   
>>   	WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
>>   	WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
>>   	WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
>>   
>>   #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
>> -	pte = pfn_pte(pfn, prot);
>> +	pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot);
>>   
>>   	WARN_ON(!pte_huge(pte_mkhuge(pte)));
>>   #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
>>   }
>>   #else  /* !CONFIG_HUGETLB_PAGE */
>> -static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
>> +static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
>>   #endif /* CONFIG_HUGETLB_PAGE */
>>   
>>   #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> @@ -1157,7 +1157,7 @@ static int __init debug_vm_pgtable(void)
>>   	pgprot_t prot, protnone;
>>   	phys_addr_t paddr;
>>   	unsigned long vaddr, pte_aligned, pmd_aligned;
>> -	unsigned long pud_aligned, p4d_aligned, pgd_aligned;
>> +	unsigned long pud_aligned;
>>   	spinlock_t *ptl = NULL;
>>   	int idx, ret;
>>   
>> @@ -1200,8 +1200,6 @@ static int __init debug_vm_pgtable(void)
>>   	pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
>>   	pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
>>   	pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
>> -	p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
>> -	pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
>>   	WARN_ON(!pfn_valid(pte_aligned));
>>   
>>   	pgdp = pgd_offset(mm, vaddr);
>> @@ -1235,9 +1233,9 @@ static int __init debug_vm_pgtable(void)
>>   	 * given page table entry.
>>   	 */
>>   	for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
>> -		pte_basic_tests(pte_aligned, idx);
>> -		pmd_basic_tests(pmd_aligned, idx);
>> -		pud_basic_tests(mm, pud_aligned, idx);
>> +		pte_basic_tests(&args, idx);
>> +		pmd_basic_tests(&args, idx);
>> +		pud_basic_tests(&args, idx);
>>   	}
>>   
>>   	/*
>> @@ -1247,8 +1245,9 @@ static int __init debug_vm_pgtable(void)
>>   	 * the above iteration for now to save some test execution
>>   	 * time.
>>   	 */
>> -	p4d_basic_tests(p4d_aligned, prot);
>> -	pgd_basic_tests(pgd_aligned, prot);
>> +	p4d_basic_tests();
>> +	pgd_basic_tests();
>> +	hugetlb_basic_tests(&args);
>>   
>>   	pmd_leaf_tests(pmd_aligned, prot);
>>   	pud_leaf_tests(pud_aligned, prot);
>> @@ -1277,8 +1276,6 @@ static int __init debug_vm_pgtable(void)
>>   	pmd_thp_tests(pmd_aligned, prot);
>>   	pud_thp_tests(pud_aligned, prot);
>>   
>> -	hugetlb_basic_tests(pte_aligned, prot);
>> -
>>   	/*
>>   	 * Page table modifying tests. They need to hold
>>   	 * proper page table lock.
>>

Thanks,
Gavin