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 D85F91F1313; Sat, 15 Nov 2025 02:20:42 +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=1763173242; cv=none; b=ZSjzE+DJRiFtz3XxIqdHe1/8Vv52mtwp5FtMgvKfuAtAkt3AlpRJlEBd1dAsT2lc3+VKZOcTB2p70VJo7g2d6+2+3zMyIZhpBBmLpC1/ul+vVRKL+Hi/58KJDRiLsR7auM0MbwvuDjYxsGbjFoP0GnzW8truoEMPQNmppHaetyA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763173242; c=relaxed/simple; bh=1nbnsS4EqlOU2qhDQ7Tb3xjj4GMZ9cC54/ecuLvYD6I=; h=Content-Type:MIME-Version:Subject:From:Message-Id:Date:References: In-Reply-To:To:Cc; b=P8O2h12ZSynJ8orVfhx/fjAJ9MTh6ZVWypreo/KoM+sgcHcgW6LYAW+Z0ikd6tzYqCViysg6LicErOPSqMt7dU+6+mlCh+r7YnkPdJEXl1/YhZORMsSotsgn0kbuyMHVuC1vpfzO25bqnxBiKJB1XMhMtLySh2ZhC63w6FD6aPA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vEEftl0t; 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="vEEftl0t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 579E6C4CEF8; Sat, 15 Nov 2025 02:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763173242; bh=1nbnsS4EqlOU2qhDQ7Tb3xjj4GMZ9cC54/ecuLvYD6I=; h=Subject:From:Date:References:In-Reply-To:To:Cc:From; b=vEEftl0tcrRC4jXXSWLWksXw53WnJvCpsY+wntW6mK2dpgZjNceyubJ71a8jB+tv/ 8ZPe0JgiRR2gOv77GxmhSdaFi7wEZ2Tadt7XA/FVpOmqgrwleeNyW3mZ77Ob+jHpF6 oJYNviHJcHkA6HnQDTwqDBStRLV6GNHY9QMKHOIxsSH6VYaVlO8Qvjl9TzJG8NlnT6 3mlJSeph8OPia4cjLR3Gu3Unh+KL/fFjwglrR9ans9gxkYQ4YeHznXXBSW610RmP5Q TShRFyWUGdWMnbhLyw+H9ENwegcjcAXQhI1xKdmVwGEVx684czfl5F+AEe9Y3ahNW1 DWN9439GWWxvQ== Received: from [10.30.226.235] (localhost [IPv6:::1]) by aws-us-west-2-korg-oddjob-rhel9-1.codeaurora.org (Postfix) with ESMTP id EAD083A78A62; Sat, 15 Nov 2025 02:20:11 +0000 (UTC) Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH net V4] veth: more robust handing of race to avoid txq getting stuck From: patchwork-bot+netdevbpf@kernel.org Message-Id: <176317321050.1911668.3467356936047783737.git-patchwork-notify@kernel.org> Date: Sat, 15 Nov 2025 02:20:10 +0000 References: <176295323282.307447.14790015927673763094.stgit@firesoul> In-Reply-To: <176295323282.307447.14790015927673763094.stgit@firesoul> To: Jesper Dangaard Brouer Cc: netdev@vger.kernel.org, toke@toke.dk, eric.dumazet@gmail.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, ihor.solodrai@linux.dev, mst@redhat.com, makita.toshiaki@lab.ntt.co.jp, toshiaki.makita1@gmail.com, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@cloudflare.com Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski : On Wed, 12 Nov 2025 14:13:52 +0100 you wrote: > Commit dc82a33297fc ("veth: apply qdisc backpressure on full ptr_ring to > reduce TX drops") introduced a race condition that can lead to a permanently > stalled TXQ. This was observed in production on ARM64 systems (Ampere Altra > Max). > > The race occurs in veth_xmit(). The producer observes a full ptr_ring and > stops the queue (netif_tx_stop_queue()). The subsequent conditional logic, > intended to re-wake the queue if the consumer had just emptied it (if > (__ptr_ring_empty(...)) netif_tx_wake_queue()), can fail. This leads to a > "lost wakeup" where the TXQ remains stopped (QUEUE_STATE_DRV_XOFF) and > traffic halts. > > [...] Here is the summary with links: - [net,V4] veth: more robust handing of race to avoid txq getting stuck https://git.kernel.org/netdev/net/c/5442a9da6978 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html