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 BA17F1A6826; Thu, 5 Mar 2026 02:55:34 +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=1772679334; cv=none; b=GgB7jpWm6Asi+Q+xY+1igNn92a61P/Up5WAPUCOz1h6vEY8QKUIHsiDMz8DR0PgrOSHIyokmg4mu7g289+07oeyi3C3vz2iYvSvPiJoEIcwMID+BEXyE6BXEvbzGPvPpyStW//PRy8ZRhv36OxijLIo/4s/rVTJESKMSFW9auZA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772679334; c=relaxed/simple; bh=4d7y/xjgWSGuhuezCdtH2976xfIP6uASlpXYDBGcWGw=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GpwMzWHp0/5XZv2wVCLbXbDo4x2E9HgsP/bdxKi7uxS2TCCvYYaOBGMGgHDlpK24WK20PdJTwiwOCUyGOO6Do63HjakRR/EMDPtVdWz1RyL2WbkJUbM0uGHsrxiYWd/dnjKvjx2IP1B5VzwfPusdOISxprwbA5JzPI3vdVGpAaA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pYK7YM4m; 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="pYK7YM4m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2664C4CEF7; Thu, 5 Mar 2026 02:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772679334; bh=4d7y/xjgWSGuhuezCdtH2976xfIP6uASlpXYDBGcWGw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pYK7YM4m0fnSsQAyhefMcDaOBvn8Y9c20FaOvCpYggIpa60A8z3EWxFyPSfPRL9FU REN3e4tRWW1m7oG26k1oqS+4aO937R4czODpAvvERAsyQWEQMzozLXDSJml7d3155z jcXg03aXYVxS0lHpCo0e59gkB2hrJHpLLVbwZU5kMt/dzDbqrUe3XWteUg9Db2G9AZ 7CMUJ2C/mOnC6YdoiPoF+jNUvhw4vyDicAInnAmtwaJ8ckXg8wYOq8SMe7YFrs82cG +bU8uWFw2JBclJCUuwTUOm5ex6kn+DfB7sKrnPaJvlby8tgUkH8ayRDaMdRV+ro3nH mC/rbafRFsa9A== Date: Wed, 4 Mar 2026 18:55:31 -0800 From: Jakub Kicinski To: Larysa Zaremba Cc: bpf@vger.kernel.org, Claudiu Manoil , Vladimir Oltean , Wei Fang , Clark Wang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Tony Nguyen , Przemek Kitszel , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Hao Luo , Jiri Olsa , Simon Horman , Shuah Khan , Alexander Lobakin , Maciej Fijalkowski , "Bastien Curutchet (eBPF Foundation)" , Tushar Vyavahare , Jason Xing , "Ricardo B. =?UTF-8?B?TWFybGnDqHJl?=" , Eelco Chaudron , Lorenzo Bianconi , Toke Hoiland-Jorgensen , imx@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-kselftest@vger.kernel.org, Aleksandr Loktionov , Dragos Tatulea Subject: Re: [PATCH bpf v4 0/9] Address XDP frags having negative tailroom Message-ID: <20260304185531.4f49fda4@kernel.org> In-Reply-To: <20260302161723.858616-1-larysa.zaremba@intel.com> References: <20260302161723.858616-1-larysa.zaremba@intel.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 2 Mar 2026 17:17:13 +0100 Larysa Zaremba wrote: > Aside from the issue described below, tailroom calculation does not account > for pages being split between frags, e.g. in i40e, enetc and > AF_XDP ZC with smaller chunks. These series address the problem by > calculating modulo (skb_frag_off() % rxq->frag_size) in order to get > data offset within a smaller block of memory. Please note, xskxceiver > tail grow test passes without modulo e.g. in xdpdrv mode on i40e, > because there is not enough descriptors to get to flipped buffers. This was re-assigned to netdev in pw, I presume by BPF maintainers. But it doesn't apply to net. There's a conflict in ice. Could you rebase on net and repost? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BF8BCEFCE43 for ; Thu, 5 Mar 2026 02:55:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 64E51608CB; Thu, 5 Mar 2026 02:55:38 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id SVMibDODBONg; Thu, 5 Mar 2026 02:55:37 +0000 (UTC) X-Comment: SPF check N/A for local connections - client-ip=140.211.166.142; helo=lists1.osuosl.org; envelope-from=intel-wired-lan-bounces@osuosl.org; receiver= DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org D388A608FC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osuosl.org; s=default; t=1772679337; bh=AS003hYPMKVNDBZvHRWuPlXHnvYEF5VFOEacKtuMb3E=; h=Date:From:To:Cc:In-Reply-To:References:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=Z9S1TBaH4Xz2d20/0N8/YTz8rKqpV/QbR1pQQpWdWWOefyg0aHGWJ2xpTIP/isLnE 3RO6N2mzWXcgcm3CzEJpvug9aAiqlVSRJHyarIdYopAg9SVdWqVQokxf4WyEGwzmC7 camQM/euUkIWSXDXwRIqBBMnmX7hJ1TDnvg7qA8+XAJcVLwZp4ghcCG6tZ3f/q4ZGO VrKUcN5CUmLmRNhP0NcLSF6vroIn+kjcV1YRwc4tGgnLlV0tEJdxnRaeO15NIF0ndu HXrFLmB2/YREJYvHEm0KVwL61ZsHkWc5u6vJMMgob1N1xcuCvltGr9TkCdxiZpT6BL WbHkkEMXMT03w== Received: from lists1.osuosl.org (lists1.osuosl.org [140.211.166.142]) by smtp3.osuosl.org (Postfix) with ESMTP id D388A608FC; Thu, 5 Mar 2026 02:55:37 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists1.osuosl.org (Postfix) with ESMTP id CA8FA223 for ; Thu, 5 Mar 2026 02:55:35 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id BC595608FC for ; Thu, 5 Mar 2026 02:55:35 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id RQ1b162yMdlO for ; Thu, 5 Mar 2026 02:55:35 +0000 (UTC) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=172.234.252.31; helo=sea.source.kernel.org; envelope-from=kuba@kernel.org; receiver= DMARC-Filter: OpenDMARC Filter v1.4.2 smtp3.osuosl.org 246A4608CB DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 246A4608CB Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by smtp3.osuosl.org (Postfix) with ESMTPS id 246A4608CB for ; Thu, 5 Mar 2026 02:55:34 +0000 (UTC) Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 88F6D404ED; Thu, 5 Mar 2026 02:55:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A2664C4CEF7; Thu, 5 Mar 2026 02:55:32 +0000 (UTC) Date: Wed, 4 Mar 2026 18:55:31 -0800 From: Jakub Kicinski To: Larysa Zaremba Cc: bpf@vger.kernel.org, Claudiu Manoil , Vladimir Oltean , Wei Fang , Clark Wang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Tony Nguyen , Przemek Kitszel , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Hao Luo , Jiri Olsa , Simon Horman , Shuah Khan , Alexander Lobakin , Maciej Fijalkowski , "Bastien Curutchet (eBPF Foundation)" , Tushar Vyavahare , Jason Xing , "Ricardo B. =?UTF-8?B?TWFybGnDqHJl?=" , Eelco Chaudron , Lorenzo Bianconi , Toke Hoiland-Jorgensen , imx@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-kselftest@vger.kernel.org, Aleksandr Loktionov , Dragos Tatulea Message-ID: <20260304185531.4f49fda4@kernel.org> In-Reply-To: <20260302161723.858616-1-larysa.zaremba@intel.com> References: <20260302161723.858616-1-larysa.zaremba@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772679334; bh=4d7y/xjgWSGuhuezCdtH2976xfIP6uASlpXYDBGcWGw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pYK7YM4m0fnSsQAyhefMcDaOBvn8Y9c20FaOvCpYggIpa60A8z3EWxFyPSfPRL9FU REN3e4tRWW1m7oG26k1oqS+4aO937R4czODpAvvERAsyQWEQMzozLXDSJml7d3155z jcXg03aXYVxS0lHpCo0e59gkB2hrJHpLLVbwZU5kMt/dzDbqrUe3XWteUg9Db2G9AZ 7CMUJ2C/mOnC6YdoiPoF+jNUvhw4vyDicAInnAmtwaJ8ckXg8wYOq8SMe7YFrs82cG +bU8uWFw2JBclJCUuwTUOm5ex6kn+DfB7sKrnPaJvlby8tgUkH8ayRDaMdRV+ro3nH mC/rbafRFsa9A== X-Mailman-Original-Authentication-Results: smtp3.osuosl.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org X-Mailman-Original-Authentication-Results: smtp3.osuosl.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=pYK7YM4m Subject: Re: [Intel-wired-lan] [PATCH bpf v4 0/9] Address XDP frags having negative tailroom X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" On Mon, 2 Mar 2026 17:17:13 +0100 Larysa Zaremba wrote: > Aside from the issue described below, tailroom calculation does not account > for pages being split between frags, e.g. in i40e, enetc and > AF_XDP ZC with smaller chunks. These series address the problem by > calculating modulo (skb_frag_off() % rxq->frag_size) in order to get > data offset within a smaller block of memory. Please note, xskxceiver > tail grow test passes without modulo e.g. in xdpdrv mode on i40e, > because there is not enough descriptors to get to flipped buffers. This was re-assigned to netdev in pw, I presume by BPF maintainers. But it doesn't apply to net. There's a conflict in ice. Could you rebase on net and repost?