Re: [PATCH] MIPS: make userspace mapping young by default

Nicholas Piggin
2021-02-04T11:36:46Z

Excerpts from Thomas Bogendoerfer's message of February 4, 2021 8:34 pm:
> On Thu, Feb 04, 2021 at 01:29:26PM +1000, Nicholas Piggin wrote:
>> Excerpts from Huang Pei's message of February 4, 2021 11:39 am:
>> > MIPS page fault path(except huge page) takes 3 exceptions (1 TLB Miss
>> > + 2 TLB Invalid), butthe second TLB Invalid exception is just
>> > triggered by __update_tlb from do_page_fault writing tlb without
>> > _PAGE_VALID set. With this patch, user space mapping prot is made
>> > young by default (with both _PAGE_VALID and _PAGE_YOUNG set),
>> > and it only take 1 TLB Miss + 1 TLB Invalid exception
>> >
>> > Remove pte_sw_mkyoung without polluting MM code and make page fault
>> > delay of MIPS on par with other architecture
>> >
>> > Signed-off-by: Huang Pei <huangpei@loongson.cn>
>>
>> Could we merge this? For the core code,
>
> sure, but IMHO I should only merge the MIPS part, correct ?

You could ack it for MIPS and Andrew could take it through his tree
would avoid dependencies.

Thanks,
Nick