From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EFD426AC3; Mon, 13 Jan 2025 16:16:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736784989; cv=none; b=FYB57dxvBqabS34K8qtzlGa2UcYtrMTYhD5ZVl3YT8rR/10ITcpxETQ5u747A2tCQ4ALiF4DUmPhNn3l879HoqbJeuFBZIuQWKmo/l0uRgyMT/31t7iU8HZ8ggp3zXxr4klUu8J3jaaYP++rjo2weM2Lp6DCPs4sLpFbPOV3bWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736784989; c=relaxed/simple; bh=IEvc23cC3czyXNqETuVossVcOEIiCltxG59+/3Dqy+k=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DVcDmz6tOudhW5JTiGOwIOQJ5dl3UwW3HgzeRalkQOOG/kMLRK2DAuZHTjPLSGpjzQQlr/Q1/qt98FAncXu/mON3iE8j9ZT8IjUmKTiVAlBYqNJ9yEcd6OE5I2xVuj9Pn0tyHIC0Zi3KDX27gQIY9kRa4E1tDD/STu0cPpj3q+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WaQBIjQK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WaQBIjQK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 778EDC4CED6; Mon, 13 Jan 2025 16:16:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736784989; bh=IEvc23cC3czyXNqETuVossVcOEIiCltxG59+/3Dqy+k=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=WaQBIjQKqRDp4iQU/EZPDTZIpQm3MWO4xQEr8qq9zg4/yEkPIJBHI5MIko8FpdSlc GgYY8zmU226FSh6FBcPySUxwLD33W/7e4NYS9v9+vAc9QHwmjQ9dTajUVHg4uzFH/z qNvm20+xnu46zOYUyfycbFQECRjr6g0T0PrvpFSpL0GWaKv1JOe5cNmv36ldmcQ45k wZjsswP/raj3UzHyAagwWFzPlwQmr1fOCvVQdZIM5ChvV0hJIxIQrLROo7VFOz2g2h 7C53IKLeHo8MDVLSudJJQ5e6ZnP87aXLyaaKFRf+lWzRHnKTncayT9vIph0fCKsbxI nhBCRJMzMqXuw== Message-ID: <95b33055-5cb4-4ba0-880f-f39a565c963b@kernel.org> Date: Mon, 13 Jan 2025 17:16:23 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net-next v2 1/2] net: remove init_dummy_netdev() Content-Language: en-GB To: Jakub Kicinski Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, martineau@kernel.org, geliang@kernel.org, steffen.klassert@secunet.com, herbert@gondor.apana.org.au, mptcp@lists.linux.dev References: <20250113003456.3904110-1-kuba@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Jakub, On 13/01/2025 01:34, Jakub Kicinski wrote: > init_dummy_netdev() can initialize statically declared or embedded > net_devices. Such netdevs did not come from alloc_netdev_mqs(). > After recent work by Breno, there are the only two cases where > we have do that. > > Switch those cases to alloc_netdev_mqs() and delete init_dummy_netdev(). > Dealing with static netdevs is not worth the maintenance burden. Thank you for the patch! (...) > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 1b2e7cbb577f..c44c89ecaca6 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -47,7 +47,7 @@ static void __mptcp_destroy_sock(struct sock *sk); > static void mptcp_check_send_data_fin(struct sock *sk); > > DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); > -static struct net_device mptcp_napi_dev; > +static struct net_device *mptcp_napi_dev; > > /* Returns end sequence number of the receiver's advertised window */ > static u64 mptcp_wnd_end(const struct mptcp_sock *msk) > @@ -4147,11 +4147,13 @@ void __init mptcp_proto_init(void) > if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL)) > panic("Failed to allocate MPTCP pcpu counter\n"); > > - init_dummy_netdev(&mptcp_napi_dev); > + mptcp_napi_dev = alloc_netdev_dummy(0); This seems to initialise quite a few things that are not needed for the MPTCP case. But it doesn't seem to hurt, and the dummy net device doesn't seem to be exposed to the userspace (net devices, sysfs). So if it helps with the maintenance, it looks fine to do that. For the modifications in MPTCP code: Reviewed-by: Matthieu Baerts (NGI0) > + if (!mptcp_napi_dev) > + panic("Failed to allocate MPTCP dummy netdev\n"); > for_each_possible_cpu(cpu) { > delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu); > INIT_LIST_HEAD(&delegated->head); > - netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi, > + netif_napi_add_tx(mptcp_napi_dev, &delegated->napi, > mptcp_napi_poll); > napi_enable(&delegated->napi); > } (...) Cheers, Matt -- Sponsored by the NGI0 Core fund.