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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 589ADC433EF for ; Sat, 2 Apr 2022 14:02:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350410AbiDBOEd (ORCPT ); Sat, 2 Apr 2022 10:04:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235277AbiDBOE3 (ORCPT ); Sat, 2 Apr 2022 10:04:29 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B360E1877CF; Sat, 2 Apr 2022 07:02:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:From: References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=icAzEvW9eshnhDDfO4k2r0xUbbSJoCJF2BriJcmZNbs=; b=T2f5fscevlWSEb+/xhKV5fAIlF wpTfSa4ML3NUQn7Iy4w0Cl+WmkLxWaCwKZjCghK+UY3ec6GKTY3Dtju3O3r9RI7nhzCPVIqH+fnlH QvklxrbXyWJspyn/YcMmekOM/Nh1Iybs+P+2WQQqA9Uu7d/FmPo34+BxVaYspiZFaUtJ3Oju5oQVq Oyj9h+sR9w+Xzs0rTsg1ultpfEA5VgXRtfI6yOSAVNj3siEvv67mYnZ8ZGZjSfRzTj5XKzjBGDkl4 kEae9d4Ols3FfRk0gXyTpI/v0B67+W74Rnic+6Az+L/pFPMmlnA3SK/+DsJ+r6om94wQMglZ+mLgo sw5jmdlw==; Received: from [177.138.180.15] (helo=[192.168.1.60]) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_128_GCM:128) (Exim) id 1naeKT-0006Wc-Lz; Sat, 02 Apr 2022 16:02:14 +0200 Message-ID: Date: Sat, 2 Apr 2022 11:01:51 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [RFC 0/1] Add sysctl entry for controlling crash_kexec_post_notifiers Content-Language: en-US To: Alejandro Jimenez , corbet@lwn.net, mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, linux@rasmusvillemoes.dk, ebiggers@google.com, peterz@infradead.org, ying.huang@intel.com, mchehab+huawei@kernel.org, Jason@zx2c4.com, daniel@iogearbox.net, robh@kernel.org, wangqing@vivo.com, prestwoj@gmail.com, dsahern@kernel.org, stephen.s.brennan@oracle.com References: <20220401202300.12660-1-alejandro.j.jimenez@oracle.com> From: "Guilherme G. Piccoli" In-Reply-To: <20220401202300.12660-1-alejandro.j.jimenez@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/04/2022 17:22, Alejandro Jimenez wrote: > I noticed that in contrast to other kernel core parameters (e.g. kernel.panic, > kernel.panic_on_warn, kernel.panic_print) crash_kexec_post_notifiers is not > available as a sysctl tunable. I am aware that because it is a kernel core > parameter, there is already an entry under: > > /sys/module/kernel/parameters/crash_kexec_post_notifiers > > and that allows us to read/modify it at runtime. However, I thought it should > also be available via sysctl, since users that want to read/set this value at > runtime might look there first. > > I believe there is an ongoing effort to clean up kernel/sysctl.c, but it wasn't > clear to me if this entry (and perhaps the other panic related entries too) > should be placed on kernel/panic.c. I wanted to verify first that this change > would be welcomed before doing additional refactoring work. > > I'd appreciate any comments or suggestions. > > Thank you, > Alejandro Hi Alejandro, thanks for you patch. I have a "selfish" concern though, I'll expose it here. I'm working a panic refactor, in order to split the panic notifiers in more lists - good summary of this discussion at [0]. I'm in the half of the patches, hopefully next 2 weeks I have something ready to submit (I'll be out next week). As part of this effort, I plan to have a more fine-grained control of this parameter, and it's going to be a sysctl, but not "crash_kexec_post_notifiers" - this one should be kept I guess due to retro-compatibility, but it'd be a layer on top oh the new one. With that said, unless you have urgent needs for this patch to be reviewed/merged , I'd like to ask you to wait the series and I can loop you there, so you may review/comment and see if it fits your use case. Thanks, Guilherme [0] https://lore.kernel.org/lkml/YfPxvzSzDLjO5ldp@alley/