Re: [RFC PATCH net-next v8 07/14] page_pool: devmem support

David Wei
2024-05-06T00:29:22Z

On 2024-05-01 00:55, Christoph Hellwig wrote:
> On Fri, Apr 26, 2024 at 05:17:52PM -0700, David Wei wrote:
>> On 2024-04-02 5:20 pm, Mina Almasry wrote:
>>> @@ -69,20 +106,26 @@ net_iov_binding(const struct net_iov *niov)
>>> */
>>> typedef unsigned long __bitwise netmem_ref;
>>>
>>> +static inline bool netmem_is_net_iov(const netmem_ref netmem)
>>> +{
>>> +#if defined(CONFIG_PAGE_POOL) && defined(CONFIG_DMA_SHARED_BUFFER)
>>
>> I am guessing you added this to try and speed up the fast path? It's
>> overly restrictive for us since we do not need dmabuf necessarily. I
>> spent a bit too much time wondering why things aren't working only to
>> find this :(
>
> So what else do you need? I was assured last round that nothing but
> dmabuf and potentially the huge page case (that really just is the page
> provider) would get added.

I'm using userspace memory so having this gated behind
CONFIG_DMA_SHARED_BUFFER doesn't make sense for us.

>
>>
> ---end quoted text---