From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.189.cn (189sx01-ptr.21cn.com [125.88.204.37]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DAFEC2AD10; Sun, 19 Apr 2026 00:21:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=125.88.204.37 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776558075; cv=none; b=EgulFwpClsmhipTdZgJ/sVEkbzK8zAT7uBtdmRWUCmkTEvotnVsOGo4KIcLBFIclobUfBNXfIkTqhauDto4NUFh2wE+F49odX8NI8k9t/WQJd3Z20bgloxZ4PYKvlTkSsvc3gp6SGikuvH7S0yX7dOKT9kTAwBDTX4COecqWmkg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776558075; c=relaxed/simple; bh=n7RvdwwyxgFcYjvNyAgeH/BTooOtpphxA4vkMUajWJk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=myOH+z4IeAJ4edgLFcyR0RKAMg3cr38R+zLUBd3smmVsAj2xiUbDvOENbGcxdShv2P0CDzBQFpvcQiKqo7D7EEdtAmVs3rw4Pvz/VP3uNXFYFQFsqpZGU1lP6Xtqi607JXpWZkaOWrXSULG33owbJ0nDP0n1CI6zCVepmG97fVg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=189.cn; spf=pass smtp.mailfrom=189.cn; arc=none smtp.client-ip=125.88.204.37 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=189.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=189.cn HMM_SOURCE_IP:10.158.242.145:0.272028814 HMM_ATTACHE_NUM:0000 HMM_SOURCE_TYPE:SMTP Received: from clientip-60.27.224.181 (unknown [10.158.242.145]) by mail.189.cn (HERMES) with SMTP id A4E65400083; Sun, 19 Apr 2026 08:21:08 +0800 (CST) Received: from ([60.27.224.181]) by gateway-153622-dep-76cc7bc9cd-r45x9 with ESMTP id 7f3f162eb12d49658ed84c9b5a5c81dd for david.laight.linux@gmail.com; Sun, 19 Apr 2026 08:21:11 CST X-Transaction-ID: 7f3f162eb12d49658ed84c9b5a5c81dd X-Real-From: chensong_2000@189.cn X-Receive-IP: 60.27.224.181 X-MEDUSA-Status: 0 Sender: chensong_2000@189.cn Message-ID: <5838a534-8ec3-4bb5-bbce-4271fd456cc3@189.cn> Date: Sun, 19 Apr 2026 08:21:06 +0800 Precedence: bulk X-Mailing-List: live-patching@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/2] kernel/notifier: replace single-linked list with double-linked list for reverse traversal To: David Laight Cc: rafael@kernel.org, lenb@kernel.org, mturquette@baylibre.com, sboyd@kernel.org, viresh.kumar@linaro.org, agk@redhat.com, snitzer@kernel.org, mpatocka@redhat.com, bmarzins@redhat.com, song@kernel.org, yukuai@fnnas.com, linan122@huawei.com, jason.wessel@windriver.com, danielt@kernel.org, dianders@chromium.org, horms@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, paulmck@kernel.org, frederic@kernel.org, mcgrof@kernel.org, petr.pavlu@suse.com, da.gomez@kernel.org, samitolvanen@google.com, atomlin@atomlin.com, jpoimboe@kernel.org, jikos@kernel.org, mbenes@suse.cz, pmladek@suse.com, joe.lawrence@redhat.com, rostedt@goodmis.org, mhiramat@kernel.org, mark.rutland@arm.com, mathieu.desnoyers@efficios.com, linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-clk@vger.kernel.org, linux-pm@vger.kernel.org, live-patching@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, netdev@vger.kernel.org References: <20260415070137.17860-1-chensong_2000@189.cn> <20260416133004.07bd2886@pumpkin> Content-Language: en-US From: Song Chen In-Reply-To: <20260416133004.07bd2886@pumpkin> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 4/16/26 20:30, David Laight wrote: > On Wed, 15 Apr 2026 15:01:37 +0800 > chensong_2000@189.cn wrote: > >> From: Song Chen >> >> The current notifier chain implementation uses a single-linked list >> (struct notifier_block *next), which only supports forward traversal >> in priority order. This makes it difficult to handle cleanup/teardown >> scenarios that require notifiers to be called in reverse priority order. > > If it is only cleanup/teardown then the list can be order-reversed > as part of that process at the same time as the list is deleted. > > David > > > Sorry, i don't follow, the notifiers in the list are deleted when calling notifier_chain_unregister, other than that, they are traversed forward and backward. Song