From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794612504; b=nezlaTuwxRrv92+sNoKyNGIrUg9walaDAbffk+zar0LPbAtYGSv57SvNhXzkqGr2zbFT bgxPOCvINYwUi9t4P+WD2f23tCcL5RHLTEnSHdHhPe5iOgruZGZ7C8mMuKXzTe9PEsYpo Q3f0/odWL4fGlbK3YKO25yjIRJv0LwHehgQecrC+KmRZUe4W/Mpv46/OZpouuBC4c7Jiu 0yfqhwwAcqvQvQcKaHgebPTP8r/MZmwB+ydVf8bOs9lxBqBMOGb2h2qsOZuCiLx5ht4wY FyPLwRYfduNHA56S+yxpV5RoAFokUtFee4EqfQP5Zrjr6LCuPSvrPP3L2nTdMi5icyw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794612504; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=MP44A2UXd/wSnusowTnecNPA/CsL40YpZ+6cXn2Yq5o=; b=Sq5txMwUbRcGJx5ttnQLWn6OD5y7q2rqBAWaKvjSWRLTOM2yUQ4qQCCFrNZ+XXwfnKzt 6njcjO3AhrEg7egMoYfMoBpEAy+1eDecl73tUJKQztEgiehr9Bb2ib03gXOPwh6HdbiTR 4albzVmDlrgFJno7nRjw3vpNxTcjm+HyPbAVDmuawqqrVDxmrRQpMrmNdCeKJJhJN9kwr UWHJNkPTTKufBAAkEvHUy4vvyVNEwsosut4x5SfI/orlsEaqtYJ2V90HBOvXy1sbm4iYH lVGbmOzYbfsyEE0ruun5vO+Q/7qFpRU0oGVuZKcs/LwMNtP2FNZ4qW5rq8zI5P1+byw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BFmsfKiM; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 52857606A327; Fri, 13 Nov 2026 23:28:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BFmsfKiM Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91BCF1F000C4; Fri, 13 Nov 2026 23:28:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794612503; bh=MP44A2UXd/wSnusowTnecNPA/CsL40YpZ+6cXn2Yq5o=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=BFmsfKiMNSSguxngG5T8TrvzhBZikBS8lfNfuEiBlybN5vaxLk351fbzf17HP53qs KNUCvlZMeITfQazmYnj5eztC02HQcH9cnSPy0tTc7P3gvsNrNyd+9EWzuoBQR6F7wP qOH9TJmA3PVAhoimmwyWEDtxiDgat5iyUjNjRct/FDqggt18zC6NYyBvmiGqljqtQp QCSyGIE4sQ50KkB1Aggc+ity1nl7SdzXHTIVUTLYeafC9xkDtFahIjvAbVbJFtXDSA DvwsuK9aIJE+5t5x2PZ1DQw8KG+ez35Km2Fcn8vT+g6qFT8Tis0pg3m/c6XwCy7JFk ILuB/iQ+Rm2/g== Date: Fri, 13 Nov 2026 15:28:21 -0800 From: Jakub Kicinski To: Ding Meng Cc: netdev@vger.kernel.org, Willem de Bruijn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Jonathan Corbet , Andrew Lunn , Tony Nguyen , Przemek Kitszel , Steven Rostedt , Masami Hiramatsu , Daniel Borkmann , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , Richard Cochran , florian.bezdeka@siemens.com, jan.kiszka@siemens.com, wq.wang@siemens.com, p@1g4.org, gerhard@engleder-embedded.com, Jason Xing , Simon Horman , Shuah Khan , Randy Dunlap , Mathieu Desnoyers , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Ihor Solodrai , John Fastabend , Stanislav Fomichev , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH] net: mark skb NAPI IDs independently of busy polling Message-ID: <20261113152821.47e9d219@kernel.org> In-Reply-To: <4pqljild2fp6eotiicvwbwu2wfw66fzd4qamwt6utirdjxlaok@iiu2f3k7azrp> References: <20261105071706.7043-1-meng.ding@siemens.com> <20261110134539.12d860ef@kernel.org> <4pqljild2fp6eotiicvwbwu2wfw66fzd4qamwt6utirdjxlaok@iiu2f3k7azrp> X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 12 Nov 2026 12:33:57 +0800 Ding Meng wrote: > On Tue, Nov 10, 2026 at 01:45:39PM -0800, Jakub Kicinski wrote: > > On Thu, 5 Nov 2026 15:16:08 +0800 Ding Meng wrote: > > > + interface index will be returned only if CONFIG_SKB_MARK_NAPI_ID is > > > + enabled and the driver is using NAPI. This hidden configuration is > > > + selected automatically by busy-poll support and by drivers that need > > > + skb NAPI IDs to resolve deferred hardware timestamps. Drivers that > > > + use deferred timestamp conversion must select it so the networking > > > + stack can find the device and call its timestamp callback even when > > > + busy polling is disabled. The struct contains also two other fields, > > > + but they are reserved and undefined. > > > > Just take napi_id from under CONFIG_NET_RX_BUSY_POLL instead of > > complicating everyone's lives. > > -- > > pw-bot: cr > > When BUSY_POLL is n under PREEMPT_RT && NETCONSOLE, igc fails to get RX > hardware timestamps. > > Then, drivers that use deferred timestamp conversion (e.g. igc, engleder) must > specify a busy poll dependency if they want to obtain the original net > device upon consuming the skb. However, this dependency is far from > obvious, and annotating it for future features of this kind will be very > hard to discover. > > Configuring the skb napi ID separately > from busy poll seems cleaner and more reasonable. "take from under" == make it always compiled in