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Message-ID: <8357256a-f0e9-4640-8fec-23341fc607db@davidwei.uk>
Date: Fri, 26 Apr 2024 17:17:52 -0700
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Subject: Re: [RFC PATCH net-next v8 07/14] page_pool: devmem support
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To: Mina Almasry <almasrymina@google.com>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
 linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org,
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Cc: "David S. Miller" <davem@davemloft.net>,
 Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>,
 Paolo Abeni <pabeni@redhat.com>, Jonathan Corbet <corbet@lwn.net>,
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 Ivan Kokshaysky <ink@jurassic.park.msu.ru>, Matt Turner
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 Jiri Olsa <jolsa@kernel.org>, Steffen Klassert
 <steffen.klassert@secunet.com>, Herbert Xu <herbert@gondor.apana.org.au>,
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 Shuah Khan <shuah@kernel.org>, Sumit Semwal <sumit.semwal@linaro.org>,
 =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
 Amritha Nambiar <amritha.nambiar@intel.com>,
 Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
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 linux-mm@kvack.org, Matthew Wilcox <willy@infradead.org>
References: <20240403002053.2376017-1-almasrymina@google.com>
 <20240403002053.2376017-8-almasrymina@google.com>
From: David Wei <dw@davidwei.uk>
In-Reply-To: <20240403002053.2376017-8-almasrymina@google.com>
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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 :(