From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3A24D2931ED; Fri, 14 Aug 2026 01:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786670474; cv=none; b=VGnsa+6wTbLogj3LMJEy+70SZ3y7Z/WCRsPQ007SbXXKNqKMwkumB1W8Es6E9+f466QYOwir5EPm7DKBA3DY3Mx9+bhxBzmo8gmOg86vQTdyrSOaAKmX0nCOqsi74DWgGGW3htvs/hwVv0keHAWxDhzfxyCSHAUJO1VjLGgUges= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786670474; c=relaxed/simple; bh=6MOFBcAQJtz1KEg++7AS+7cnBXyHvg/Mg13dg/EVhc0=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=HSJS4A2ihK8o8P0rjnex8Y1wTahBpbwdj9kfCzUzppnCG/MDnn9g4zs0ShpvbE3PDxNQXSYecvfsGqrxZT6qsIs6y+DpXnLCGk13f2THvbfMAoBoZLrY1iyHhlod+Gfw1gUVGmNnIjCCTdHIj5eJm0VXsHk/W0Y14CsQjtEqH1s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EoaDoWzx; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EoaDoWzx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 307021F00A3A; Fri, 14 Aug 2026 01:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786670472; bh=pGd/Nbzf0/woxXyoYCLtltZgiXfrqaFQ0VzYyGSlY9Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=EoaDoWzxXblj9tj2w4XsJDIbThDRImzmJQF+XQPKbxAzU6+sByK98iJBj1kp/7eFc 4vGOBoEk5u34FzYu4qtlZqMwdiaV6bTTr1FtaRD/6UCbjasAvc1hXaMU7ox/PfmQvC JcSU46+3zd9vrdz+AbnVnJq3RC/7CNcUNFhGzKPYQreYN/dz2ov7WOT2OTnVGlIRhm VNlQ5mQladFHrkokfAihIDvNFP2cNo0EJTCq5JKrTJc1VQI0oh/RP8EPt3A568ab8j iY3PcIxYqyFwNeHY2KfE51d3w38p9LKG5DQUFN6I8eSbUkfcCQeXBh+NU+cwpGGShY OxmjLFQzTIlZw== Date: Thu, 13 Aug 2026 18:21:11 -0700 From: Jakub Kicinski To: Xin Xie Cc: netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, andrew+netdev@lunn.ch, shuah@kernel.org, kees@kernel.org, petr.wozniak@gmail.com, qingfang.deng@linux.dev, fmaurer@redhat.com, luka.gejak@linux.dev, bigeasy@linutronix.de, xiaoliang.yang_1@nxp.com, skhawaja@google.com, liuhangbin@gmail.com, stable@vger.kernel.org, sdf.kernel@gmail.com Subject: Re: [PATCH 1/4] net: hsr: fix packet drops caused by GRO superpackets Message-ID: <20260813182111.088aee3d@kernel.org> In-Reply-To: <20260809121455.1745-2-xiexinet@gmail.com> References: <20260809121455.1745-1-xiexinet@gmail.com> <20260809121455.1745-2-xiexinet@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@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 Sun, 9 Aug 2026 14:14:51 +0200 Xin Xie wrote: > HSR/PRP process each wire frame separately for tagging and duplicate > discard. GRO on a lower device hides multiple frames in one skb, which > cannot be forwarded with valid per-frame metadata. > > Disable GRO and GRO_HW when a lower device is enslaved, matching the > existing LRO handling. > > This is best effort because GRO may be re-enabled and some devices cannot > disable GRO_HW. The forward-entry segmentation fix handles plain, > trailer-free GSO skbs that still arrive; device-specific fixed-on GRO_HW > output is outside this guarantee. 1) could you explain in more detail why GRO is breaking things? GRO shouldn't merge packets with different L2/L2.5 and packets with trailers? 2) the code seems inspired by LRO but LRO also has NETIF_F_UPPER_DISABLES. This change looks rather incomplete. Calling it "best effort" seems like an excuse. 3) Clashiko has a number of other comments: https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260809121455.1745-1-xiexinet@gmail.com -- pw-bot: cr