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 AE413C43217 for ; Sun, 28 Nov 2021 00:31:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356717AbhK1AeU (ORCPT ); Sat, 27 Nov 2021 19:34:20 -0500 Received: from rere.qmqm.pl ([91.227.64.183]:24740 "EHLO rere.qmqm.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356618AbhK1AcS (ORCPT ); Sat, 27 Nov 2021 19:32:18 -0500 Received: from remote.user (localhost [127.0.0.1]) by rere.qmqm.pl (Postfix) with ESMTPSA id 4J1q8r4xRGz9Y; Sun, 28 Nov 2021 01:28:44 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rere.qmqm.pl; s=1; t=1638059340; bh=BpCUv6sc6+ijt8bP2X1dBPBQztb08CMPEjcmSI4mWHs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E2pJXVdwpF7xa7NgJpuaA7I4sUgCSxdIM51ma240k1OvyN0BqmbHCll/qibc7LmRW l2lYyRdiOG0LzZZRcQGCbOEp7l5l7FW2EF13o78tAxh2BlfQLPIqSf2RtHjwNL3AHE ag5QLlLhW95Kp8fH9dCV3j4Imx5XQ5T4nV1vyleMAzKz1Soq6c6OnKpJ5TdzfdwJ2G LnQoKtgUWmpQEblg3IMnaxzgslueaP8apjKdZ9y96JJ35QjeXKQSawNEPmoxjBztTd XADr6Ffb3r0e7Kv67f/UCkeky+8m4GCPkGRqXkdYh2BWzTit8bUIHp4dPNUh/LgLHY SH/yCd1X39o+Q== X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.3 at mail Date: Sun, 28 Nov 2021 01:28:40 +0100 From: =?iso-8859-2?Q?Micha=B3_Miros=B3aw?= To: Dmitry Osipenko Cc: Thierry Reding , Jonathan Hunter , Russell King , Catalin Marinas , Will Deacon , Guo Ren , Geert Uytterhoeven , Greg Ungerer , Joshua Thompson , Thomas Bogendoerfer , Sebastian Reichel , Linus Walleij , Philipp Zabel , Greentime Hu , Vincent Chen , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Paul Walmsley , Palmer Dabbelt , Albert Ou , Yoshinori Sato , Rich Felker , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , "Rafael J. Wysocki" , Len Brown , Santosh Shilimkar , Krzysztof Kozlowski , Liam Girdwood , Mark Brown , Pavel Machek , Lee Jones , Andrew Morton , Guenter Roeck , Daniel Lezcano , Andy Shevchenko , Ulf Hansson , alankao@andestech.com, "K . C . Kuen-Chern Lin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH v4 05/25] reboot: Warn if restart handler has duplicated priority Message-ID: References: <20211126180101.27818-1-digetx@gmail.com> <20211126180101.27818-6-digetx@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20211126180101.27818-6-digetx@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 26, 2021 at 09:00:41PM +0300, Dmitry Osipenko wrote: > Add sanity check which ensures that there are no two restart handlers > registered with the same priority. Normally it's a direct sign of a > problem if two handlers use the same priority. The patch doesn't ensure the property that there are no duplicated-priority entries on the chain. I'd rather see a atomic_notifier_chain_register_unique() that returns -EBUSY or something istead of adding an entry with duplicate priority. That way it would need only one list traversal unless you want to register the duplicate anyway (then you would call the older atomic_notifier_chain_register() after reporting the error). (Or you could return > 0 when a duplicate is registered in atomic_notifier_chain_register() if the callers are prepared for that. I don't really like this way, though.) Best Regards Michał Mirosław