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From: Anshuman Khandual <anshuman.khandual@arm.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	linux-mm@kvack.org, akpm@linux-foundation.org
Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 16/16] debug_vm_pgtable/ppc64: Add a variant of pfn_pte/pmd
Date: Thu, 13 Aug 2020 11:00:56 +0530	[thread overview]
Message-ID: <fe7beb39-97e6-dd7c-59d4-e1a72bab3d71@arm.com> (raw)
In-Reply-To: <20200812063358.369514-16-aneesh.kumar@linux.ibm.com>


On 08/12/2020 12:03 PM, Aneesh Kumar K.V wrote:
> The tests do expect _PAGE_PTE bit set by different page table accessors.
> This is not true for the kernel. Within the kernel, _PAGE_PTE bits are
> usually set by set_pte_at(). To make the below tests work correctly add test
> specific pfn_pte/pmd helpers that set _PAGE_PTE bit.
> 
> pte_t pte = pfn_pte(pfn, prot);
> WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
> WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  mm/debug_vm_pgtable.c | 65 +++++++++++++++++++++++++++----------------
>  1 file changed, 41 insertions(+), 24 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index eea62d5e503b..153c925b5273 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -31,6 +31,23 @@
>  #include <asm/pgalloc.h>
>  #include <asm/tlbflush.h>
>  
> +#ifdef CONFIG_PPC_BOOK3S_64
> +static inline pte_t debug_vm_pfn_pte(unsigned long pfn, pgprot_t pgprot)
> +{
> +	pte_t pte = pfn_pte(pfn, pgprot);
> +	return __pte(pte_val(pte) | _PAGE_PTE);
> +
> +}
> +static inline pmd_t debug_vm_pfn_pmd(unsigned long pfn, pgprot_t pgprot)
> +{
> +	pmd_t pmd = pfn_pmd(pfn, pgprot);
> +	return __pmd(pmd_val(pmd) | _PAGE_PTE);
> +}
> +#else
> +#define debug_vm_pfn_pte(pfn, pgprot) pfn_pte(pfn, pgprot)
> +#define debug_vm_pfn_pmd(pfn, pgprot) pfn_pmd(pfn, pgprot)
> +#endif

Again, no platform specific constructs please. This defeats the whole purpose of
this test. If __PAGE_PTE is required for the helpers, then pfn_pmd/pte() could
be modified to accommodate that. We dont see similar issues on other platforms,
hence could you please explain why ppc64 is different here.


WARNING: multiple messages have this Message-ID (diff)
From: Anshuman Khandual <anshuman.khandual@arm.com>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>,
	linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 16/16] debug_vm_pgtable/ppc64: Add a variant of pfn_pte/pmd
Date: Thu, 13 Aug 2020 11:00:56 +0530	[thread overview]
Message-ID: <fe7beb39-97e6-dd7c-59d4-e1a72bab3d71@arm.com> (raw)
In-Reply-To: <20200812063358.369514-16-aneesh.kumar@linux.ibm.com>


On 08/12/2020 12:03 PM, Aneesh Kumar K.V wrote:
> The tests do expect _PAGE_PTE bit set by different page table accessors.
> This is not true for the kernel. Within the kernel, _PAGE_PTE bits are
> usually set by set_pte_at(). To make the below tests work correctly add test
> specific pfn_pte/pmd helpers that set _PAGE_PTE bit.
> 
> pte_t pte = pfn_pte(pfn, prot);
> WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
> WARN_ON(!pte_savedwrite(pte_mk_savedwrite(pte_clear_savedwrite(pte))));
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  mm/debug_vm_pgtable.c | 65 +++++++++++++++++++++++++++----------------
>  1 file changed, 41 insertions(+), 24 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index eea62d5e503b..153c925b5273 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -31,6 +31,23 @@
>  #include <asm/pgalloc.h>
>  #include <asm/tlbflush.h>
>  
> +#ifdef CONFIG_PPC_BOOK3S_64
> +static inline pte_t debug_vm_pfn_pte(unsigned long pfn, pgprot_t pgprot)
> +{
> +	pte_t pte = pfn_pte(pfn, pgprot);
> +	return __pte(pte_val(pte) | _PAGE_PTE);
> +
> +}
> +static inline pmd_t debug_vm_pfn_pmd(unsigned long pfn, pgprot_t pgprot)
> +{
> +	pmd_t pmd = pfn_pmd(pfn, pgprot);
> +	return __pmd(pmd_val(pmd) | _PAGE_PTE);
> +}
> +#else
> +#define debug_vm_pfn_pte(pfn, pgprot) pfn_pte(pfn, pgprot)
> +#define debug_vm_pfn_pmd(pfn, pgprot) pfn_pmd(pfn, pgprot)
> +#endif

Again, no platform specific constructs please. This defeats the whole purpose of
this test. If __PAGE_PTE is required for the helpers, then pfn_pmd/pte() could
be modified to accommodate that. We dont see similar issues on other platforms,
hence could you please explain why ppc64 is different here.

  reply	other threads:[~2020-08-13  5:31 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-12  6:33 [PATCH 01/16] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Aneesh Kumar K.V
2020-08-12  6:33 ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 02/16] debug_vm_pgtable/ppc64: Avoid setting top bits in radom value Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12  6:40   ` Christophe Leroy
2020-08-12  6:43     ` Aneesh Kumar K.V
2020-08-12  8:12   ` Anshuman Khandual
2020-08-12  8:12     ` Anshuman Khandual
2020-08-12  8:25     ` Aneesh Kumar K.V
2020-08-12  8:25       ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 03/16] debug_vm_pgtable/set_pte: Don't use set_pte_at to update an existing pte entry Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12  9:12   ` Anshuman Khandual
2020-08-12  9:12     ` Anshuman Khandual
2020-08-12  9:22     ` Aneesh Kumar K.V
2020-08-12  9:22       ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 04/16] debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 10:30   ` Anshuman Khandual
2020-08-12 10:30     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 05/16] debug_vm_pgtable/savedwrite: Enable savedwrite test with CONFIG_NUMA_BALANCING Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 11:24   ` Anshuman Khandual
2020-08-12 11:24     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 06/16] debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd_at Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 07/16] debug_vm_pgtable/THP: Mark the pte entry huge before using set_pud_at Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 11:49   ` Anshuman Khandual
2020-08-12 11:49     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 08/16] debug_vm_pgtable/set_pmd: Don't use set_pmd_at to update an existing pmd entry Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 12:46   ` Anshuman Khandual
2020-08-12 12:46     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 09/16] debug_vm_pgtable/set_pud: Don't use set_pud_at to update an existing pud entry Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 12:46   ` Anshuman Khandual
2020-08-12 12:46     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 10/16] debug_vm_pgtable/thp: Use page table depost/withdraw with THP Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-13  5:25   ` Anshuman Khandual
2020-08-13  5:25     ` Anshuman Khandual
2020-08-13  6:38     ` Aneesh Kumar K.V
2020-08-13  6:38       ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 11/16] debug_vm_pgtable/locks: Move non page table modifying test together Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 12/16] debug_vm_pgtable/locks: Take correct page table lock Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 13/16] debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-13  5:27   ` Anshuman Khandual
2020-08-13  5:27     ` Anshuman Khandual
2020-08-13  8:45     ` Aneesh Kumar K.V
2020-08-13  8:45       ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 14/16] debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64 Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 13:03   ` Anshuman Khandual
2020-08-12 13:03     ` Anshuman Khandual
2020-08-12 13:16     ` Aneesh Kumar K.V
2020-08-12 13:16       ` Aneesh Kumar K.V
2020-08-12 13:34       ` Anshuman Khandual
2020-08-12 13:34         ` Anshuman Khandual
2020-08-12 13:52         ` Aneesh Kumar K.V
2020-08-12 13:52           ` Aneesh Kumar K.V
2020-08-14  8:43           ` Anshuman Khandual
2020-08-14  8:43             ` Anshuman Khandual
2020-08-19  6:54             ` Aneesh Kumar K.V
2020-08-19  6:54               ` Aneesh Kumar K.V
2020-08-12  6:33 ` [PATCH 15/16] debug_vm_pgtable/savedwrite: Use savedwrite test with protnone ptes Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-12 13:06   ` Anshuman Khandual
2020-08-12 13:06     ` Anshuman Khandual
2020-08-12  6:33 ` [PATCH 16/16] debug_vm_pgtable/ppc64: Add a variant of pfn_pte/pmd Aneesh Kumar K.V
2020-08-12  6:33   ` Aneesh Kumar K.V
2020-08-13  5:30   ` Anshuman Khandual [this message]
2020-08-13  5:30     ` Anshuman Khandual
2020-08-13  6:37     ` Aneesh Kumar K.V
2020-08-13  6:37       ` Aneesh Kumar K.V
2020-08-14  8:29       ` Anshuman Khandual
2020-08-14  8:29         ` Anshuman Khandual
2020-08-12  7:46 ` [PATCH 01/16] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Anshuman Khandual
2020-08-12  7:46   ` Anshuman Khandual
2020-08-12  8:27   ` Aneesh Kumar K.V
2020-08-12  8:27     ` Aneesh Kumar K.V

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