Re: [PATCH net-next v7 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA

On 2023/8/22 23:38, Jakub Kicinski wrote:

On Tue, 22 Aug 2023 17:21:35 +0800 Yunsheng Lin wrote:

quoted

quoted

.. we should also add a:

	WARN_ONCE(1, "misaligned DMA address, please report to netdev@");  

As the CONFIG_PHYS_ADDR_T_64BIT seems to used widely in x86/arm/mips/powerpc,
I am not sure if we can really make the above assumption.

https://elixir.free-electrons.com/linux/v6.4-rc6/K/ident/CONFIG_PHYS_ADDR_T_64BIT

Huh, it's actually used a lot less than I anticipated!

None of the x86/arm/mips/powerpc systems matter IMHO - the only _real_

Is there any particular reason that you think that the above systems does
not really matter?

As we have made a similar wrong assumption about those arches before, I am
really trying to be more cautious about it.

I searched through the web, some seems to be claiming that "32-bits is DEAD",
I am not sure if there is some common agreement among the kernel community,
is there any previous discussion about that?