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 5E73D14EC73; Tue, 3 Mar 2026 00:22:54 +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=1772497374; cv=none; b=FdrQlhgtn0ELxHz+vP6iHUBmc9PwvNB+IxKQzVW798u2QUv5IWgVFmQC+7TrNFtXUDci5GR7aN8oPTR9XzCqieZBFWFhnu8g+D0ePNn054Vu80AeWjiLyRw2a+oAnfSUYM21Y5og4mUI/jIjm7shqHhVyPPZq4xT2h4ubOZKTqU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772497374; c=relaxed/simple; bh=fAHXYp2r3bJPizvrvjmdRZRYidtkZyUM69F1y4kVVXA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dDzumsgW/T4WYewCskfl+f91et/3lIDIMGHn4w6gRYYWPfGtyL5Hi+27PPrjgpwAX1sHeTnkvfgwnlrsQ0Zqy2fytYsiHk8Ts3ggOnnXUEmNrgj6btW7Jv+FCMmDXZr/zF15w/44ou+FzOAyla9D0OrvbA21sc3fJsFgnoHffCQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rgQeRtaA; 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="rgQeRtaA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15560C19423; Tue, 3 Mar 2026 00:22:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772497374; bh=fAHXYp2r3bJPizvrvjmdRZRYidtkZyUM69F1y4kVVXA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rgQeRtaA4WA1WOjzSj0cpBWLaQdh5dTsmRX33aH1EzDWIsBXoPaVXlbJI+JGneRWd IlCXUuVJucoNiiYRK83CTfUZt3U2oiTdaEv/T+rGzAT7b1Mn9wlI4DoGaaEEtZGdD/ efDrwLGhdBb6eVhPBC+gllZtrSQzWdznNyufNl+XoxtVZSAtFaVknF2cnw2AtQIe6s cSucRR9yoezpv/llIPZjhCcXxSBjZCJGAO3lgHW60s2BOKVtN6iO3AT59i8bOUfw9p x6g7DPT/dLpekGrZN6L9QF0gI5LrzfIusKCMsPQKjZMbg7h4rqA+4Y9wr5eNn+xasu lhyJDR8zP6OEg== Date: Mon, 2 Mar 2026 16:22:51 -0800 From: Jakub Kicinski To: Leon Hwang Cc: Leon Hwang , netdev@vger.kernel.org, "David S . Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Jonathan Corbet , Shuah Khan , David Ahern , Neal Cardwell , Kuniyuki Iwashima , Ilpo =?UTF-8?B?SsOkcnZpbmVu?= , Ido Schimmel , kerneljasonxing@gmail.com, lance.yang@linux.dev, jiayuan.chen@linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH net-next] tcp: Add net.ipv4.tcp_purge_receive_queue sysctl Message-ID: <20260302162251.733b520e@kernel.org> In-Reply-To: References: <20260225074633.149590-1-leon.huangfu@shopee.com> <20260225174354.5a698ddb@kernel.org> 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 Mon, 2 Mar 2026 17:55:59 +0800 Leon Hwang wrote: > On 26/2/26 09:43, Jakub Kicinski wrote: > > On Wed, 25 Feb 2026 15:46:33 +0800 Leon Hwang wrote: > >> Issue: > >> When a TCP socket in the CLOSE_WAIT state receives a RST packet, the > >> current implementation does not clear the socket's receive queue. This > >> causes SKBs in the queue to remain allocated until the socket is > >> explicitly closed by the application. As a consequence: > >> > >> 1. The page pool pages held by these SKBs are not released. > > > > On what kernel version and driver are you observing this? > > # uname -r > 6.19.0-061900-generic > > # ethtool -i eth0 > driver: mlx5_core > version: 6.19.0-061900-generic > firmware-version: 26.43.2566 (MT_0000000531) Okay... this kernel + driver should just patiently wait for the page pool to go away. What is the actual, end user problem that you're trying to solve? A few kB of data waiting to be freed is not a huge problem..