From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
linux-mm@kvack.org, akpm@linux-foundation.org
Cc: linuxppc-dev@lists.ozlabs.org,
Anshuman Khandual <anshuman.khandual@arm.com>
Subject: Re: [PATCH 02/16] debug_vm_pgtable/ppc64: Avoid setting top bits in radom value
Date: Wed, 12 Aug 2020 12:13:29 +0530 [thread overview]
Message-ID: <d196a2e1-3d6a-6c6b-fc6d-8cc32095b269@linux.ibm.com> (raw)
In-Reply-To: <24b1e523-e87e-161b-3dc9-60bd11c8f461@csgroup.eu>
On 8/12/20 12:10 PM, Christophe Leroy wrote:
>
>
> Le 12/08/2020 à 08:33, Aneesh Kumar K.V a écrit :
>> 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 | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
>> index 086309fb9b6f..4c32063a8acf 100644
>> --- a/mm/debug_vm_pgtable.c
>> +++ b/mm/debug_vm_pgtable.c
>> @@ -45,9 +45,12 @@
>> * 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.
>> + *
>> + * 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 PPC_MASK_BITS 2
>> +#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1 - PPC_MASK_BITS,
>> S390_MASK_BITS)
>
> Do you mean:
>
> #define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, PPC_MASK_BITS |
> S390_MASK_BITS)
IIUC GENMASK(hi, low) generate a mask from hi to low bits. Since i want
to avoid bit 62, I am forcing it to generate bits from (61, 4)
-aneesh
next prev parent reply other threads:[~2020-08-12 7:08 UTC|newest]
Thread overview: 43+ 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 ` [PATCH 02/16] debug_vm_pgtable/ppc64: Avoid setting top bits in radom value Aneesh Kumar K.V
2020-08-12 6:40 ` Christophe Leroy
2020-08-12 6:43 ` Aneesh Kumar K.V [this message]
2020-08-12 8:12 ` Anshuman Khandual
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 9:12 ` Anshuman Khandual
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 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 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 ` [PATCH 07/16] debug_vm_pgtable/THP: Mark the pte entry huge before using set_pud_at Aneesh Kumar K.V
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 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 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
2020-08-13 5:25 ` Anshuman Khandual
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 ` [PATCH 12/16] debug_vm_pgtable/locks: Take correct page table lock 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
2020-08-13 5:27 ` Anshuman Khandual
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 13:03 ` Anshuman Khandual
2020-08-12 13:16 ` Aneesh Kumar K.V
2020-08-12 13:34 ` Anshuman Khandual
2020-08-12 13:52 ` Aneesh Kumar K.V
2020-08-14 8:43 ` Anshuman Khandual
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 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
2020-08-13 5:30 ` Anshuman Khandual
2020-08-13 6:37 ` Aneesh Kumar K.V
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 8:27 ` Aneesh Kumar K.V
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