From patchwork Wed Apr 27 22:49:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guilherme G. Piccoli" X-Patchwork-Id: 12829758 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 0B91EC433F5 for ; Wed, 27 Apr 2022 23:02:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239884AbiD0XFf (ORCPT ); Wed, 27 Apr 2022 19:05:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240692AbiD0XES (ORCPT ); Wed, 27 Apr 2022 19:04:18 -0400 Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 923C6B3DDD; Wed, 27 Apr 2022 15:57:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: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=C9iT/xJ8gF8J/f7SmqQO2c8pu+KvBPlFfkqGdYboS2I=; b=PMFgjQG40D4y0EE10+nqxAPHVI yNLZ1EZJdP0IH30iYafdBfM788VaINOAVfe8Gnevld0DclzQJRd8t+br/vJapdawGOEWHQTLdmHei 1IQvYGZ//MLpN+QQDVtOXWSfDQyyspNE1J3gOgOC4NUam3dGx8JeBgJ9jpYRHFoaP71Y3fG1ERN+7 JvwIb059Xf3lNBTrEP8JiyuPOh5ugwSvNao5NfaR+bMPV8BospKPkEU02jshVAtp1UBbOdjrRb2r2 ze90RIwfaZigyOQntmQCmXs163wt4gsMUWHmf1nSoidLeEjFKj9WA7H531Eyz4iqvzof4LvLiIP9u dq8Lxg9g==; Received: from [179.113.53.197] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1njqbL-0002UI-QD; Thu, 28 Apr 2022 00:57:40 +0200 From: "Guilherme G. Piccoli" To: akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, coresight@lists.linaro.org, linuxppc-dev@lists.ozlabs.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-edac@vger.kernel.org, linux-hyperv@vger.kernel.org, linux-leds@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-pm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, linux-tegra@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, netdev@vger.kernel.org, openipmi-developer@lists.sourceforge.net, rcu@vger.kernel.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, kernel-dev@igalia.com, gpiccoli@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, Benjamin Herrenschmidt , Hari Bathini , Michael Ellerman , Nicholas Piggin , Paul Mackerras Subject: [PATCH 27/30] powerpc: Do not force all panic notifiers to execute before kdump Date: Wed, 27 Apr 2022 19:49:21 -0300 Message-Id: <20220427224924.592546-28-gpiccoli@igalia.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220427224924.592546-1-gpiccoli@igalia.com> References: <20220427224924.592546-1-gpiccoli@igalia.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Commit 06e629c25daa ("powerpc/fadump: Fix inaccurate CPU state info in vmcore generated with panic") introduced a hardcoded setting of kernel parameter "crash_kexec_post_notifiers", effectively forcing all the panic notifiers to execute earlier in the panic path, before kdump. The reason for that was a fadump issue on collecting data accurately, due to smp_send_stop() setting all CPUs offline, so the net effect desired with this change was to avoid calling the regular CPU shutdown function, and instead rely on crash_smp_send_stop(), which copes fine with fadump. The collateral effect was to increase the risk for kdump if fadump is not used, since it forces all panic notifiers to execute early, before kdump. Happens that, after a panic refactor, crash_smp_send_stop() is now used by default in the panic path, so there is no reason to mess with the notifiers ordering (which was also improved in the refactor) from within arch code. Fixes: 06e629c25daa ("powerpc/fadump: Fix inaccurate CPU state info in vmcore generated with panic") Cc: Benjamin Herrenschmidt Cc: Hari Bathini Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Paul Mackerras Signed-off-by: Guilherme G. Piccoli --- We'd like to thanks specially the MiniCloud infrastructure [0] maintainers, that allow us to test PowerPC code in a very complete, functional and FREE environment. [0] https://openpower.ic.unicamp.br/minicloud arch/powerpc/kernel/fadump.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c index 65562c4a0a69..35ae8c09af66 100644 --- a/arch/powerpc/kernel/fadump.c +++ b/arch/powerpc/kernel/fadump.c @@ -1649,14 +1649,6 @@ int __init setup_fadump(void) register_fadump(); } - /* - * In case of panic, fadump is triggered via ppc_panic_event() - * panic notifier. Setting crash_kexec_post_notifiers to 'true' - * lets panic() function take crash friendly path before panic - * notifiers are invoked. - */ - crash_kexec_post_notifiers = true; - return 1; } /*