Re: [PATCH v6 3/4] arm64: use both ZONE_DMA and ZONE_DMA32

[Nicolas Saenz Julienne]

On Mon, 2019-10-21 at 13:25 -0400, Qian Cai wrote:
> > On Oct 21, 2019, at 1:01 PM, Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> > wrote:
> > 
> > Could you enable CMA debugging to see if anything interesting comes out of
> > it.
> 
> I did but nothing interesting came out. Did you use the same config I gave?

Yes, aside from enabling ZONE_DMA.

> Also, it has those cmdline.
>
> page_poison=on page_owner=on numa_balancing=enable \
> systemd.unified_cgroup_hierarchy=1 debug_guardpage_minorder=1 \
> page_alloc.shuffle=1

No luck, still works for me even after adding those extra flags. IIRC most of
them (if not all) are not even parsed by the time CMA is configured.

So, can you confirm the zones setup you're seeing is similar to this one:

[    0.000000][    T0] Zone ranges:
[    0.000000][    T0]   DMA      [mem 0x00000000802f0000-0x00000000bfffffff]
[    0.000000][    T0]   DMA32    [mem 0x00000000c0000000-0x00000000ffffffff]
[    0.000000][    T0]   Normal   [mem 0x0000000100000000-0x00000093fcffffff]

Maybe your memory starts between 0xe0000000-0xffffffff. That would be
problematic (although somewhat unwarranted).

Regards,
Nicolas

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