Re: [PATCH V12] mm/debug: Add tests validating architecture page table helpers

Christophe Leroy
2020-02-03T15:14:30Z

Le 02/02/2020 à 12:26, Qian Cai a écrit :
>
>
>> On Jan 30, 2020, at 9:13 AM, Christophe Leroy <christophe.leroy@c-s.fr> wrote:
>>
>> config DEBUG_VM_PGTABLE
>> bool "Debug arch page table for semantics compliance" if ARCH_HAS_DEBUG_VM_PGTABLE || EXPERT
>> depends on MMU
>> default 'n' if !ARCH_HAS_DEBUG_VM_PGTABLE
>> default 'y' if DEBUG_VM
>
> Does it really necessary to potentially force all bots to run this? Syzbot, kernel test robot etc? Does it ever pay off for all their machine times there?
>

Machine time ?

On a 32 bits powerpc running at 132 MHz, the tests takes less than 10ms.
Is it worth taking the risk of not detecting faults by not selecting it
by default ?

[ 5.656916] debug_vm_pgtable: debug_vm_pgtable: Validating
architecture page table helpers
[ 5.665661] debug_vm_pgtable: debug_vm_pgtable: Validated
architecture page table helpers

Christophe