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 5629AC07E97 for ; Fri, 1 Dec 2023 11:55:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378655AbjLALzu (ORCPT ); Fri, 1 Dec 2023 06:55:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1378585AbjLALzs (ORCPT ); Fri, 1 Dec 2023 06:55:48 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2a07:de40:b251:101:10:150:64:1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4BCC1B4 for ; Fri, 1 Dec 2023 03:55:54 -0800 (PST) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 8C09A21A43; Fri, 1 Dec 2023 11:55:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1701431753; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=G7vJ6YHg1yf1wXh0BFGY+i3PS9hKihQbt0xDIMplNys=; b=Wd35BYDuN03/Sw3Tcau0xgrTofCMLtCPdLEuwtzmpEuTLjGc/qffasRDDGF6YWZlOUCnVD dk/iyFT/i2HVpUzxMC8OV8H3nPqsTACBKcj3xf8DJFJH4ye3issVNTIvQ/tqSNgEwb22Kt MjCiThSLh3J6lkmvvHAtuBG6U2i2Nbc= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 6C4201369E; Fri, 1 Dec 2023 11:55:53 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Uv1SF8nJaWWIfwAAD6G6ig (envelope-from ); Fri, 01 Dec 2023 11:55:53 +0000 Date: Fri, 1 Dec 2023 12:55:52 +0100 From: Michal Hocko To: Philipp Rudo Cc: Baoquan He , Donald Dutile , Jiri Bohac , Pingfan Liu , Tao Liu , Vivek Goyal , Dave Young , kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/4] kdump: crashkernel reservation from CMA Message-ID: References: <91a31ce5-63d1-7470-18f7-92b039fda8e6@redhat.com> <20231201123353.2b3db7fa@rotkaeppchen> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231201123353.2b3db7fa@rotkaeppchen> Authentication-Results: smtp-out1.suse.de; none X-Spamd-Result: default: False [-0.62 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; RCPT_COUNT_SEVEN(0.00)[10]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_NOT_FQDN(0.50)[]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-0.02)[54.77%] Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 01-12-23 12:33:53, Philipp Rudo wrote: [...] > And yes, those are all what-if concerns but unfortunately that is all > we have right now. Should theoretical concerns without an actual evidence (e.g. multiple drivers known to be broken) become a roadblock for this otherwise useful feature? > Only alternative would be to run extended tests in > the field. Which means this user facing change needs to be included. > Which also means that we are stuck with it as once a user facing change > is in it's extremely hard to get rid of it again... I am not really sure I follow you here. Are you suggesting once crashkernel=cma is added it would become a user api and therefore impossible to get rid of? -- Michal Hocko SUSE Labs