Re: [PATCH net-next v4 1/5] page_pool: frag API support for 32-bit arch with 64-bit DMA

[Alexander Lobakin]

From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
Date: Wed, 14 Jun 2023 11:36:28 +0800

> On 2023/6/13 21:30, Alexander Lobakin wrote:
>> From: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
>> Date: Mon, 12 Jun 2023 21:02:52 +0800

[...]

>> I addressed this in my series, which I hope will land soon after yours
>> (sending new revision in 24-48 hours), so you can leave it as it is. Or
>> otherwise you can pick my solution (or come up with your own :D).
> 
> Do you mean by removing "#include <linux/dma-direction.h>" as dma-mapping.h
> has included dma-direction.h?

By "I addressed" I meant that I dropped including page_pool.h from
skbuff.h, as I also had to include dma-mapping.h to page_pool.h and this
implied that half of the kernel started including dma-mapping.h as well
for no profit.

> But I am not sure if there is any hard rule about not explicitly including
> a .h which is implicitly included. What if the dma-mapping.h is changed to not
> include dma-direction.h anymore?

No hard rule, but I don't see a reason for redundant includes. I usually
try to keep include lists as small as possible.

> 
> Anyway, it seems it is unlikely to not include dma-direction.h in dma-mapping.h,
> Will remove the "#include <linux/dma-direction.h>" if there is another version
> needed for this patchset:)
> 
>>
>>>  
>>>  #define PP_FLAG_DMA_MAP		BIT(0) /* Should page_pool do the DMA
Thanks,
Olek