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

Christophe Leroy
2021-02-08T17:44:30Z

Le 06/02/2021 à 00:41, Andrew Morton a écrit :
> On Thu, 4 Feb 2021 16:22:39 +0100 Thomas Bogendoerfer <tsbogend@alpha.franken.de> wrote:
>
>> On Thu, Feb 04, 2021 at 09:39:42AM +0800, Huang Pei wrote:
>>> 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>
>>> ---
>>> arch/mips/mm/cache.c | 30 ++++++++++++++++--------------
>>> include/linux/pgtable.h | 8 --------
>>> mm/memory.c | 3 ---
>>> 3 files changed, 16 insertions(+), 25 deletions(-)
>>
>> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
>>
>> Andrew, can you take this patch through your tree ?
>
> Sure. I'll drop Christophe's "mm/memory.c: remove pte_sw_mkyoung()"
> (https://lkml.kernel.org/r/f302ef92c48d1f08a0459aaee1c568ca11213814.1612345700.git.christophe.leroy@csgroup.eu)
> in favour of this one.
>

Pitty. My patch was improving page faults on powerpc/32. That one is only addressing MIPS.

Any plan to take the series from Nick
https://patchwork.kernel.org/project/linux-mm/list/?series=404539 ?

Christophe