Re: [PATCH 1/4] m68k/mm: motorola - Add missing initialization of max_pfn

Geert Uytterhoeven
2015-11-17T19:54:30Z

Hi Michael,

On Tue, Nov 17, 2015 at 5:42 AM, Michael Schmitz <schmitzmic@gmail.com> wrote:
> Am 16.11.2015 um 00:04 schrieb Geert Uytterhoeven:
>> If max_pfn is not initialized, the various /proc/kpage* files are empty,
>> and selftests/vm/mlock2-tests will fail. max_pfn is also used by the
>> block layer to calculate DMA masks.
>
> What about platforms where the DMA can't address all available physical
> memory?

There are many other checks, using max_low_pfn and/or zone_dma.
I'm not 100% clear on the impact of max_pfn in blk_settings_init().

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds