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 660CDC4332F for ; Tue, 22 Nov 2022 15:07:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232517AbiKVPHQ (ORCPT ); Tue, 22 Nov 2022 10:07:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233973AbiKVPGv (ORCPT ); Tue, 22 Nov 2022 10:06:51 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8BEA2E5; Tue, 22 Nov 2022 07:06:49 -0800 (PST) Received: from zn.tnic (p200300ea9733e79b329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9733:e79b:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 14C1C1EC04E2; Tue, 22 Nov 2022 16:06:48 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1669129608; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=5yMV1ZCNV3SL3KeDjf/6/5dfqDL8Ilh1prBf3IRM6ZU=; b=Wx1aIkqqyXz34T4ijeYsjo3X4fIguA60r9PaSI5S4+6cUmM14EhfTJMcwsE9KXP70C9FwM BhiTrP9Sz7nraeCt/sT3Gowww7prx3tsfmZUcBL5oLO9iCscr/hsHZ+emgo9QKxcUukwZ1 6w0KNHT8mxHXL5v7BJ0K0Cm25jdAlpw= Date: Tue, 22 Nov 2022 16:06:42 +0100 From: Borislav Petkov To: "Guilherme G. Piccoli" , Tony Luck , Rabara Niravkumar L Cc: Dinh Nguyen , linux-edac@vger.kernel.org, kexec@lists.infradead.org, pmladek@suse.com, linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net Subject: Re: [PATCH V3 08/11] EDAC/altera: Skip the panic notifier if kdump is loaded Message-ID: References: <20220819221731.480795-1-gpiccoli@igalia.com> <20220819221731.480795-9-gpiccoli@igalia.com> <742d2a7e-efee-e212-178e-ba642ec94e2a@igalia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org On Tue, Nov 22, 2022 at 10:33:12AM -0300, Guilherme G. Piccoli wrote: Leaving in the whole thing for newly added people. > On 18/09/2022 11:10, Guilherme G. Piccoli wrote: > > On 19/08/2022 19:17, Guilherme G. Piccoli wrote: > >> The altera_edac panic notifier performs some data collection with > >> regards errors detected; such code relies in the regmap layer to > >> perform reads/writes, so the code is abstracted and there is some > >> risk level to execute that, since the panic path runs in atomic > >> context, with interrupts/preemption and secondary CPUs disabled. > >> > >> Users want the information collected in this panic notifier though, > >> so in order to balance the risk/benefit, let's skip the altera panic > >> notifier if kdump is loaded. While at it, remove a useless header > >> and encompass a macro inside the sole ifdef block it is used. > >> > >> Cc: Borislav Petkov > >> Cc: Petr Mladek > >> Cc: Tony Luck > >> Acked-by: Dinh Nguyen > >> Signed-off-by: Guilherme G. Piccoli > >> > >> --- > >> > >> V3: > >> - added the ack tag from Dinh - thanks! > >> - had a good discussion with Boris about that in V2 [0], > >> hopefully we can continue and reach a consensus in this V3. > >> [0] https://lore.kernel.org/lkml/46137c67-25b4-6657-33b7-cffdc7afc0d7@igalia.com/ > >> > >> V2: > >> - new patch, based on the discussion in [1]. > >> [1] https://lore.kernel.org/lkml/62a63fc2-346f-f375-043a-fa21385279df@igalia.com/ > >> > >> [...] > > > > Hi Dinh, Tony, Boris - sorry for the ping. > > > > Appreciate reviews on this one - Dinh already ACKed the patch but Boris > > raised some points in the past version [0], so any opinions or > > discussions are welcome! > > > Hi folks, monthly ping heheh > Apologies for the re-pings, please let me know if there is anything > required to move on this patch. Looking at this again, I really don't like the sprinkling of if (kexec_crash_loaded()) in unrelated code. And I still think that the real fix here is to kill this edac->panic_notifier thing. And replace it with simply logging the error from the double bit error interrupt handle. That DBERR IRQ thing altr_edac_a10_irq_handler(). Because this is what this panic notifier does - dump double-bit errors. Now, if Dinh doesn't move, I guess we can ask Tony and/or Rabara (he has sent a patch for this driver recently and Altera belongs to Intel now) to find someone who can test such a change and we (you could give it a try first :)) can do that change. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette