Re: [PATCH] powerpc/mm: Code cleanup for __hash_page_thp

Kunwu Chan
2024-02-27T03:14:43Z

Thanks for the reply.

On 2024/2/26 18:49, Michael Ellerman wrote:
> Kunwu Chan <chentao@kylinos.cn> writes:
>> This part was commented from commit 6d492ecc6489
>> ("powerpc/THP: Add code to handle HPTE faults for hugepages")
>> in about 11 years before.
>>
>> If there are no plans to enable this part code in the future,
>> we can remove this dead code.
>
> I agree the code can go. But I'd like it to be replaced with a comment
> explaining what the dead code was trying to say.
Thanks, i'll update a new patch with the following comment:
/*
* No CPU has hugepages but lacks no execute, so we
* don't need to worry about cpu no CPU_FTR_COHERENT_ICACHE feature case
*/

>
> cheers
>
>> diff --git a/arch/powerpc/mm/book3s64/hash_hugepage.c b/arch/powerpc/mm/book3s64/hash_hugepage.c
>> index c0fabe6c5a12..127a3a2c174b 100644
>> --- a/arch/powerpc/mm/book3s64/hash_hugepage.c
>> +++ b/arch/powerpc/mm/book3s64/hash_hugepage.c
>> @@ -59,16 +59,6 @@ int __hash_page_thp(unsigned long ea, unsigned long access, unsigned long vsid,
>>
>> rflags = htab_convert_pte_flags(new_pmd, flags);
>>
>> -#if 0
>> - if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
>> -
>> - /*
>> - * No CPU has hugepages but lacks no execute, so we
>> - * don't need to worry about that case
>> - */
>> - rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
>> - }
>> -#endif
>> /*
>> * Find the slot index details for this ea, using base page size.
>> */
>> --
>> 2.39.2
--
Thanks,
Kunwu