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Message-ID: <462da4bf-34f8-40c4-8772-9850b3127baf@kernel.org>
Date:   Fri, 8 Dec 2023 10:56:39 -0700
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Subject: Re: [net-next v1 07/16] netdev: netdevice devmem allocator
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To:     Mina Almasry <almasrymina@google.com>,
        Shailend Chand <shailend@google.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org,
        bpf@vger.kernel.org, linux-media@vger.kernel.org,
        dri-devel@lists.freedesktop.org
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>,
        Jeroen de Borst <jeroendb@google.com>,
        Praveen Kaligineedi <pkaligineedi@google.com>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        Ilias Apalodimas <ilias.apalodimas@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
        Shuah Khan <shuah@kernel.org>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        Yunsheng Lin <linyunsheng@huawei.com>,
        Harshitha Ramamurthy <hramamurthy@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        Willem de Bruijn <willemb@google.com>,
        Kaiyuan Zhang <kaiyuanz@google.com>
References: <20231208005250.2910004-1-almasrymina@google.com>
 <20231208005250.2910004-8-almasrymina@google.com>
From:   David Ahern <dsahern@kernel.org>
In-Reply-To: <20231208005250.2910004-8-almasrymina@google.com>
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On 12/7/23 5:52 PM, Mina Almasry wrote:
> diff --git a/net/core/dev.c b/net/core/dev.c
> index b8c8be5a912e..30667e4c3b95 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -2120,6 +2120,41 @@ static int netdev_restart_rx_queue(struct net_device *dev, int rxq_idx)
>  	return err;
>  }
>  
> +struct page_pool_iov *netdev_alloc_dmabuf(struct netdev_dmabuf_binding *binding)
> +{
> +	struct dmabuf_genpool_chunk_owner *owner;
> +	struct page_pool_iov *ppiov;
> +	unsigned long dma_addr;
> +	ssize_t offset;
> +	ssize_t index;
> +
> +	dma_addr = gen_pool_alloc_owner(binding->chunk_pool, PAGE_SIZE,

Any reason not to allow allocation sizes other than PAGE_SIZE? e.g.,
2048 for smaller MTUs or 8192 for larger ones. It can be a property of
page_pool and constant across allocations vs allowing different size for
each allocation.