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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,
	linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org,
	linux-snps-arc@lists.infradead.org, x86@kernel.org,
	linux-arch@vger.kernel.org,
	Gerald Schaefer <gerald.schaefer@de.ibm.com>,
	Christophe Leroy <christophe.leroy@c-s.fr>,
	Vineet Gupta <vgupta@synopsys.com>,
	Mike Rapoport <rppt@linux.ibm.com>, Qian Cai <cai@lca.pw>
Subject: Re: [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value
Date: Tue, 1 Sep 2020 08:45:14 +0530	[thread overview]
Message-ID: <3a0b0101-e6ec-26c5-e104-5b0bb95c3e51@arm.com> (raw)
In-Reply-To: <20200827080438.315345-4-aneesh.kumar@linux.ibm.com>



On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote:
> ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that bit in
> random value.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> ---
>  mm/debug_vm_pgtable.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 086309fb9b6f..bbf9df0e64c6 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -44,10 +44,17 @@
>   * entry type. But these bits might affect the ability to clear entries with
>   * pxx_clear() because of how dynamic page table folding works on s390. So
>   * while loading up the entries do not change the lower 4 bits. It does not
> - * have affect any other platform.
> + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
> + * used to mark a pte entry.
>   */
> -#define S390_MASK_BITS	4
> -#define RANDOM_ORVALUE	GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS)
> +#define S390_SKIP_MASK		GENMASK(3, 0)
> +#ifdef CONFIG_PPC_BOOK3S_64
> +#define PPC64_SKIP_MASK		GENMASK(62, 62)
> +#else
> +#define PPC64_SKIP_MASK		0x0
> +#endif

Please drop the #ifdef CONFIG_PPC_BOOK3S_64 here. We already accommodate skip
bits for a s390 platform requirement and can also do so for ppc64 as well. As
mentioned before, please avoid adding any platform specific constructs in the
test.

> +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
> +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
>  #define RANDOM_NZVALUE	GENMASK(7, 0)

Please fix the alignments here. Feel free to consider following changes after
this patch.

diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 122416464e0f..f969031152bb 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -48,14 +48,11 @@
  * have affect any other platform. Also avoid the 62nd bit on ppc64 that is
  * used to mark a pte entry.
  */
-#define S390_SKIP_MASK         GENMASK(3, 0)
-#ifdef CONFIG_PPC_BOOK3S_64
-#define PPC64_SKIP_MASK                GENMASK(62, 62)
-#else
-#define PPC64_SKIP_MASK                0x0
-#endif
-#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
-#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
+#define S390_SKIP_MASK GENMASK(3, 0)
+#define PPC64_SKIP_MASK        GENMASK(62, 62)
+#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK)
+#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
+
 #define RANDOM_NZVALUE GENMASK(7, 0)
 
>  
>  static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
> 

Besides, there is also one checkpatch.pl warning here.

WARNING: Possible unwrapped commit description (prefer a maximum 75 chars per line)
#7: 
ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that bit in

total: 0 errors, 1 warnings, 20 lines checked


  reply	other threads:[~2020-09-01  3:15 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-27  8:04 [PATCH v3 00/13] mm/debug_vm_pgtable fixes Aneesh Kumar K.V
2020-08-27  8:04 ` [PATCH v3 01/13] powerpc/mm: Add DEBUG_VM WARN for pmd_clear Aneesh Kumar K.V
2020-09-01  3:12   ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 02/13] powerpc/mm: Move setting pte specific flags to pfn_pte Aneesh Kumar K.V
2020-09-01  3:13   ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 03/13] mm/debug_vm_pgtable/ppc64: Avoid setting top bits in radom value Aneesh Kumar K.V
2020-09-01  3:15   ` Anshuman Khandual [this message]
2020-09-01  6:21     ` Aneesh Kumar K.V
2020-09-01  7:32       ` Anshuman Khandual
2020-09-01  7:36         ` Aneesh Kumar K.V
2020-09-01  7:46           ` Anshuman Khandual
2020-09-01  7:55             ` Aneesh Kumar K.V
2020-09-02  3:45               ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 04/13] mm/debug_vm_pgtables/hugevmap: Use the arch helper to identify huge vmap support Aneesh Kumar K.V
2020-09-01  3:16   ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 05/13] mm/debug_vm_pgtable/savedwrite: Enable savedwrite test with CONFIG_NUMA_BALANCING Aneesh Kumar K.V
2020-09-01  3:18   ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 06/13] mm/debug_vm_pgtable/THP: Mark the pte entry huge before using set_pmd/pud_at Aneesh Kumar K.V
2020-09-01  3:21   ` Anshuman Khandual
2020-09-01  6:23     ` Aneesh Kumar K.V
2020-08-27  8:04 ` [PATCH v3 07/13] mm/debug_vm_pgtable/set_pte/pmd/pud: Don't use set_*_at to update an existing pte entry Aneesh Kumar K.V
2020-08-27  8:04 ` [PATCH v3 08/13] mm/debug_vm_pgtable/thp: Use page table depost/withdraw with THP Aneesh Kumar K.V
2020-09-01  3:22   ` Anshuman Khandual
2020-09-01  6:25     ` Aneesh Kumar K.V
2020-09-01  6:50       ` Christophe Leroy
2020-09-01  7:40         ` Aneesh Kumar K.V
2020-09-01  7:51           ` Christophe Leroy
2020-09-02  3:45             ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 09/13] mm/debug_vm_pgtable/locks: Move non page table modifying test together Aneesh Kumar K.V
2020-09-01  3:41   ` Anshuman Khandual
2020-09-01  6:38     ` Aneesh Kumar K.V
2020-09-01  9:33       ` Anshuman Khandual
2020-09-01  9:36         ` Aneesh Kumar K.V
2020-09-01  9:58           ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 10/13] mm/debug_vm_pgtable/locks: Take correct page table lock Aneesh Kumar K.V
2020-09-01  3:44   ` Anshuman Khandual
2020-08-27  8:04 ` [PATCH v3 11/13] mm/debug_vm_pgtable/pmd_clear: Don't use pmd/pud_clear on pte entries Aneesh Kumar K.V
2020-08-27  8:04 ` [PATCH v3 12/13] mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64 Aneesh Kumar K.V
2020-09-01  4:03   ` Anshuman Khandual
2020-09-01  6:30     ` Aneesh Kumar K.V
2020-09-01  7:59       ` Christophe Leroy
2020-09-02 13:05       ` Anshuman Khandual
2020-09-02 13:20         ` Aneesh Kumar K.V
2020-08-27  8:04 ` [PATCH v3 13/13] mm/debug_vm_pgtable: populate a pte entry before fetching it Aneesh Kumar K.V
2020-08-27 12:17   ` kernel test robot
2020-09-01  3:25   ` Anshuman Khandual
2020-09-01  6:37     ` Aneesh Kumar K.V
2020-09-01  7:38       ` Anshuman Khandual
2020-09-01  9:58         ` Aneesh Kumar K.V
2020-09-02  3:49           ` Anshuman Khandual
2020-09-02  3:58             ` Aneesh Kumar K.V

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