Re: [PATCH v6 2/2] arm64: support batched/deferred tlb shootdown during page reclamation

Anshuman Khandual
2022-11-16T02:53:00Z

On 11/16/22 07:26, Nadav Amit wrote:
> On Nov 15, 2022, at 5:50 PM, Yicong Yang <yangyicong@huawei.com> wrote:
>
>> !! External Email
>>
>> On 2022/11/16 7:38, Nadav Amit wrote:
>>> On Nov 14, 2022, at 7:14 PM, Yicong Yang <yangyicong@huawei.com> wrote:
>>>
>>>> diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
>>>> index 8a497d902c16..5bd78ae55cd4 100644
>>>> --- a/arch/x86/include/asm/tlbflush.h
>>>> +++ b/arch/x86/include/asm/tlbflush.h
>>>> @@ -264,7 +264,8 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
>>>> }
>>>>
>>>> static inline void arch_tlbbatch_add_mm(struct arch_tlbflush_unmap_batch *batch,
>>>> - struct mm_struct *mm)
>>>> + struct mm_struct *mm,
>>>> + unsigned long uaddr)
>>>
>>> Logic-wise it looks fine. I notice the “v6", and it should not be blocking,
>>> but I would note that the name "arch_tlbbatch_add_mm()” does not make much
>>> sense once the function also takes an address.
>>
>> ok the add_mm should still apply to x86 since the address is not used, but not for arm64.
>>
>>> It could’ve been something like arch_set_tlb_ubc_flush_pending() but that’s
>>> too long. I’m not very good with naming, but the current name is not great.
>>
>> What about arch_tlbbatch_add_pending()? Considering the x86 is pending the flush operation
>> while arm64 is pending the sychronization operation, arch_tlbbatch_add_pending() should
>> make sense to both.
>
> Sounds reasonable. Thanks.

+1, agreed.