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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 80894C2BD09 for ; Wed, 10 Jul 2024 01:53:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UaBOrwyHb1jHX6Wp6ePtOxrK6kFJlXb2Y7pztTZCVW0=; b=AHRrOfQkOyXVCrsmXUDK2ZNoQd TIQrKYHUZDUQNca9eBz2P6i7eJDr3Gv0mj4BCF+NJrVm/OTQkkmBocjuA/z8heeT3FFGlD99gOqyC FeMXu7TK45D5tFqeOo9iVvFzueNHkDcsYnbixQxo/dUoiHI2HtJ+Yt2lRN3y8UaBbRM8xoI3G6HTR 6CJ7kqIo0o+j+sYMxYQaPE1DHX8tFZoV+D7pqomkZWV/NV70SJXQq6Jam2AmKv/2Hpa2rvezzJnvP Jqc28SqAzQCpxKdW1OVb8ruRSXlBkosHf3QnFzBYZv+m3X0Kue/zZ+oTLmQaXUj2LKZJli4ytol7i fRyA/DUg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sRMVn-000000097Qh-0WlZ; Wed, 10 Jul 2024 01:52:51 +0000 Received: from szxga01-in.huawei.com ([45.249.212.187]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sRMVV-000000097MA-0VQI; Wed, 10 Jul 2024 01:52:35 +0000 Received: from mail.maildlp.com (unknown [172.19.163.48]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4WJgj91sZvzwWCq; Wed, 10 Jul 2024 09:47:41 +0800 (CST) Received: from kwepemi100008.china.huawei.com (unknown [7.221.188.57]) by mail.maildlp.com (Postfix) with ESMTPS id 726A2180088; Wed, 10 Jul 2024 09:52:23 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by kwepemi100008.china.huawei.com (7.221.188.57) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Wed, 10 Jul 2024 09:52:22 +0800 Message-ID: <8aed5c59-090b-ea7e-020c-dd2785ee3d7e@huawei.com> Date: Wed, 10 Jul 2024 09:52:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH 0/3] ARM: Use generic interface to simplify crashkernel reservation Content-Language: en-US To: Baoquan He CC: , , , , , , , , , , , , , , , , , , , , References: <20240708133348.3592667-1-ruanjinjie@huawei.com> <3157befe-431f-69ac-b9d3-7a8685ba3a4d@huawei.com> <01869981-b1de-32cb-bd25-d6ea09752b3d@huawei.com> From: Jinjie Ruan In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi100008.china.huawei.com (7.221.188.57) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240709_185233_537689_3120818D X-CRM114-Status: GOOD ( 16.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2024/7/9 22:06, Baoquan He wrote: > On 07/09/24 at 07:06pm, Jinjie Ruan wrote: >> >> >> On 2024/7/9 18:39, Baoquan He wrote: >>> On 07/09/24 at 05:50pm, Jinjie Ruan wrote: >>>> >>>> >>>> On 2024/7/9 17:29, Baoquan He wrote: >>>>> On 07/08/24 at 09:33pm, Jinjie Ruan wrote: >>>>>> Currently, x86, arm64, riscv and loongarch has been switched to generic >>>>>> crashkernel reservation. Also use generic interface to simplify crashkernel >>>>>> reservation for arm32, and fix two bugs by the way. >>>>> >>>>> I am not sure if this is a good idea. I added the generic reservation >>>>> itnerfaces for ARCH which support crashkernel=,high|low and normal >>>>> crashkernel reservation, with this, the code can be simplified a lot. >>>>> However, arm32 doesn't support crashkernel=,high, I am not sure if it's >>>>> worth taking the change, most importantly, if it will cause >>>>> misunderstanding or misoperation. >>>> >>>> Yes, arm32 doesn't support crashkernel=,high. >>>> >>>> However, a little enhancement to the generic code (please see the first >>>> patch), the generic reservation interfaces can also be applicable to >>>> architectures that do not support "high" such as arm32, and it can also >>>> simplify the code (please see the third patch). >>> >>> Yeah, I can see the code is simplified. When you specified >>> 'crashkernel=xM,high', do you think what should be warn out? Because >>> it's an unsupported syntax on arm32, we should do something to print out >>> appropriate message. >> >> Yes, you are right! In this patch it will print "crashkernel high memory >> reservation failed." message and out for arm32 if you specify > > That message may mislead people to believe crashkernel=,high is > supported but reservation is failed, then a bug need be filed for this? > We may expect a message telling this syntax is not supported on this > ARCH. "CRASH_ADDR_LOW_MAX >= CRASH_ADDR_HIGH_MAX" indicate that the arm32 does not support "crashkernel=,high", I wonder if this is generic for similar architecture. If so, the first patch can print such as "crashkernel=,high is not supported on this ARCH" message. > >> 'crashkernel=xM,high because "CRASH_ADDR_LOW_MAX" and >> "CRASH_ADDR_HIGH_MAX" is identical for arm32. And it should also warn >> out for other similar architecture. >> >> >>> >>> >> > >