Re: [PATCH RFC v3 1/2] mm: Add personality flag to limit address to 47 bits

Michael Ellerman
2024-09-11T13:38:57Z

Geert Uytterhoeven <geert@linux-m68k.org> writes:
> Hi Christophe,
>
> On Tue, Sep 10, 2024 at 11:21 AM Christophe Leroy
> <christophe.leroy@csgroup.eu> wrote:
>> >>> diff --git a/include/uapi/linux/personality.h b/include/uapi/linux/personality.h
>> >>> index 49796b7756af..cd3b8c154d9b 100644
>> >>> --- a/include/uapi/linux/personality.h
>> >>> +++ b/include/uapi/linux/personality.h
>> >>> @@ -22,6 +22,7 @@ enum {
>> >>> WHOLE_SECONDS = 0x2000000,
>> >>> STICKY_TIMEOUTS = 0x4000000,
>> >>> ADDR_LIMIT_3GB = 0x8000000,
>> >>> + ADDR_LIMIT_47BIT = 0x10000000,
>> >>> };
>> >>
>> >> I wonder if ADDR_LIMIT_128T would be clearer?
>> >>
>> >
>> > I don't follow, what does 128T represent?
>>
>> 128T is 128 Terabytes, that's the maximum size achievable with a 47BIT
>> address, that naming would be more consistant with the ADDR_LIMIT_3GB
>> just above that means a 3 Gigabytes limit.
>
> Hence ADDR_LIMIT_128TB?

Yes it should be 128TB. Typo by me.

cheers