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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1606CC072A2 for ; Wed, 22 Nov 2023 05:17:58 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=PxDe4lZh; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4SZqJP49LSz3dKF for ; Wed, 22 Nov 2023 16:17:57 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=PxDe4lZh; dkim-atps=neutral Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4SZqHT2ZGJz2yjD for ; Wed, 22 Nov 2023 16:17:09 +1100 (AEDT) Received: by gandalf.ozlabs.org (Postfix) id 4SZqHS5nznz4xQZ; Wed, 22 Nov 2023 16:17:08 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1700630228; bh=TCYKc2HGVsybDUdZJckf8t5FSQftw5Rjcll+8CYTEmo=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=PxDe4lZhwi0ogRmrgnxSXD3Po6RKP4PQIE4Ky5NCk2UtjtGX1xpd9WW3FNLk6+1O8 hddsoQoCCfL9c4zug8+6ioHnMlcdH+zDI8PY9uXXhnRypx7ApiOO6WDP1XnC19YiAH l7kqt9Y59nLCZkHE9Kgo0FxJlnQh54ZP037o1JCp6a4c9rQjX6bCUByVIQ3jE7+XD7 nZ1yYs2/PWapSjDbPeEwac/bAmyudRDFc53wUkMTtrMMmTXlktp4oLtqhjrxG8dG7a upWaCmegFFa7wXPHbhi6zi9m+PW9obOCZpC/ZZwz/qUKIT6wDd6te6CBAlo5/Xg8Vi 5P5vW1EfelRYA== Received: from authenticated.ozlabs.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 mail.ozlabs.org (Postfix) with ESMTPSA id 4SZqHS50Q8z4xNG; Wed, 22 Nov 2023 16:17:08 +1100 (AEDT) From: Michael Ellerman To: Aneesh Kumar K V , Sourabh Jain , linuxppc-dev@ozlabs.org Subject: Re: [PATCH v5 1/3] powerpc: make fadump resilient with memory add/remove events In-Reply-To: <2c0f9f9d-8cc1-4bd4-8f7f-d284140ffa43@linux.ibm.com> References: <20231029124548.12198-1-sourabhjain@linux.ibm.com> <20231029124548.12198-2-sourabhjain@linux.ibm.com> <871qcr1v8v.fsf@linux.ibm.com> <1472a35a-5de9-4684-b4de-9dffebdedfbb@linux.ibm.com> <2c0f9f9d-8cc1-4bd4-8f7f-d284140ffa43@linux.ibm.com> Date: Wed, 22 Nov 2023 16:17:08 +1100 Message-ID: <87fs0yjrjf.fsf@mail.lhotse> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aditya Gupta , Mahesh Salgaonkar , Hari Bathini Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Aneesh Kumar K V writes: ... > > I am not sure whether we need to add all the complexity to enable supporting different fadump kernel > version. Is that even a possible use case with fadump? Can't we always assume that with fadump the > crash kernel and fadump kernel will be same version? How sure are we of that? Don't we go through grub when we boot into the 2nd kernel. And so couldn't it choose to boot a different kernel, for whatever reason. I don't think we need to support different pt_reg / cpumask sizes, but requiring the exact same kernel version is too strict I think. But maybe I'm wrong. Would be good to hear what distro folks think. cheers