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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C7B5C433FE for ; Wed, 2 Mar 2022 08:03:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6E6C08D0002; Wed, 2 Mar 2022 03:03:36 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 696298D0001; Wed, 2 Mar 2022 03:03:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 55DAD8D0002; Wed, 2 Mar 2022 03:03:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0072.hostedemail.com [216.40.44.72]) by kanga.kvack.org (Postfix) with ESMTP id 44EEA8D0001 for ; Wed, 2 Mar 2022 03:03:36 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 01D49181D6CFA for ; Wed, 2 Mar 2022 08:03:36 +0000 (UTC) X-FDA: 79198706832.28.3DC5D2D Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf22.hostedemail.com (Postfix) with ESMTP id 66B25C0009 for ; Wed, 2 Mar 2022 08:03:35 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 81929B81F1F; Wed, 2 Mar 2022 08:03:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3A68C004E1; Wed, 2 Mar 2022 08:03:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646208212; bh=XVSDm4zGluVMXX2dmFKSlq6Iqi3qFcUpPX6v9nTXTB0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rKq2q/mNICKglLoxy2+1EvSnfFoMr7r5D3UNcc5UUjr30Jgubk8QzMAZUGD3dav06 GycPzFaNQLBf4gFczb2zGuR6UVu+zX1vHJIQHqLrW5gGAlrL2GpFrGsGGz7xusnPBJ SZK9zDArWCZV5Er2aR2uEZEKYYaODfvcTHMCRgLtJefDpnVxyrBPPmacHjNsqXAQgw OiM2pTAI5GYwNfRNKlq2bijp69D09NV0lUrfRPJ8XZkCtLyGLKAxJYQ32dsS4gy05Y 52eELXqieoQtiJ5sZxZl1wSQ8u8rYeqMDVrSeaVMGgMBlM7WMsiGauttmVjif9Dccr lDexJrVqf0Zjw== Date: Wed, 2 Mar 2022 10:03:24 +0200 From: Mike Rapoport To: Tiezhu Yang Cc: Thomas Bogendoerfer , Andrew Morton , Xuefeng Li , linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/4] MIPS: Modify mem= and memmap= parameter Message-ID: References: <1646108941-27919-1-git-send-email-yangtiezhu@loongson.cn> <8956c625-c18d-846e-3e65-7920776b27f3@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8956c625-c18d-846e-3e65-7920776b27f3@loongson.cn> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 66B25C0009 X-Stat-Signature: z7eroyky4xmx44xnk8i8im7b81q7hda5 Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="rKq2q/mN"; spf=pass (imf22.hostedemail.com: domain of rppt@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspam-User: X-HE-Tag: 1646208215-971288 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 02, 2022 at 09:50:49AM +0800, Tiezhu Yang wrote: > > > On 03/01/2022 10:31 PM, Mike Rapoport wrote: > > On Tue, Mar 01, 2022 at 07:51:23PM +0800, Tiezhu Yang wrote: > > > > > > > > > On 03/01/2022 05:55 PM, Mike Rapoport wrote: > > > > Hi, > > > > > > > > On Tue, Mar 01, 2022 at 12:28:57PM +0800, Tiezhu Yang wrote: > > > > > In the current code, the kernel command-line parameter mem= and memmap= > > > > > can not work well on MIPS, this patchset refactors the related code to > > > > > fix them. > > > > > > > > > > For kdump on MIPS, if the users want to limit the memory region for the > > > > > capture kernel to avoid corrupting the memory image of the panic kernel, > > > > > use the parameter memmap=limit@base is the proper way, I will submit a > > > > > patch to use memmap=limit@base for kexec-tools after this patchset is > > > > > applied. > > > > > > > > Sorry, apparently I misread the prevoius version. > > > > What's wrong with the current implementation of mem=limit@base for the > > > > kdump case? > > > > > > In the current code, without this patchset, kernel boot hangs when add > > > mem=3G, mem=3G@64M or memmap=3G@64M to the command-line, it means that > > > the parameter mem= and memmap= have bug on mips. > > > > I can see how mem=3G may be wrong when the memory does not start at 0, but > > it seems to do the right thing of mem=3G@64M. > > > > Do you see system hangs with mem=3G@64M? > > Yes. > > > > > Do you have the logs before the hang? > > Here are the logs: > > [ 0.000000] Linux version 5.17.0-rc3+ (loongson@linux) (gcc (GCC) 7.3.1 > 20180303 (Red Hat 7.3.1-6), GNU ld version 2.28-13.fc21.loongson.6) #1 SMP > PREEMPT Wed Mar 2 09:07:39 CST 2022 > [ 0.000000] CpuClock = 1800000000 > [ 0.000000] The bridge chip is LS7A > [ 0.000000] CP0_Config3: CP0 16.3 (0xdc8030a0) > [ 0.000000] CP0_PageGrain: CP0 5.1 (0x28000000) > [ 0.000000] NUMA: Discovered 4 cpus on 1 nodes > [ 0.000000] Node0: mem_type:1, mem_start:0x200000, mem_size:0xee MB > [ 0.000000] start_pfn:0x80, end_pfn:0x3c00, num_physpages:0x3b80 > [ 0.000000] Node0: mem_type:2, mem_start:0x90200000, mem_size:0x6fe MB > [ 0.000000] start_pfn:0x24080, end_pfn:0x40000, > num_physpages:0x1fb00 > [ 0.000000] Node0: mem_type:2, mem_start:0x120000000, mem_size:0x1600 MB > [ 0.000000] start_pfn:0x48000, end_pfn:0xa0000, > num_physpages:0x77b00 > [ 0.000000] Node0's addrspace_offset is 0x0 > [ 0.000000] Node0: start_pfn=0x80, end_pfn=0xa0000 > [ 0.000000] NUMA: set cpumask cpu 0 on node 0 > [ 0.000000] NUMA: set cpumask cpu 1 on node 0 > [ 0.000000] NUMA: set cpumask cpu 2 on node 0 > [ 0.000000] NUMA: set cpumask cpu 3 on node 0 > [ 0.000000] printk: bootconsole [early0] enabled > [ 0.000000] CPU0 revision is: 0014c001 (ICT Loongson-3) > [ 0.000000] FPU revision is: 00f70501 > [ 0.000000] MSA revision is: 00060140 > [ 0.000000] OF: fdt: No chosen node found, continuing without > [ 0.000000] MIPS: machine is loongson,loongson64g-4core-ls7a > [ 0.000000] User-defined physical RAM map overwrite > [ 0.000000] Kernel sections are not in the memory maps > [ 0.000000] Initrd not found or empty - disabling initrd Can you please also send the log with "memblock=debug" added to the kernel command line? > > As for memmap= option, it does not specify the memory map but rather alters > > the memory map passed by the firmware. Particularity in MIPS implementation > > it allows to add a single range of available or reserved memory. > > > > AFAIU, for the kdump use-case mem=X@Y should suffice. > > We can modify some code to make mem=X@Y work well, > but according to Documentation/admin-guide/kernel-parameters.txt, > the common way is mem=X and memmap=X@Y, so mem=X@Y for mips seems > odd, the intention of this patchset is to make mem= and memmap= > work well and consistent with the other archs. These options are anyway not consistent on different architectures. arm, mips and x86 implement mem= one way and arm64, powerpc and riscv in another so there is no common way to use mem=. Your changes will break the existing systems that use mem= and memmap= options because they change the semantics of their MIPS implementation. For kexec/kdump use-cases modern architectures usually do not pass mem= but rather prepare the memory map for the kexeced kernel to use. I believe this would be the right solution. > Thanks, > Tiezhu > > > > > > Thanks, > > > Tiezhu > > > > > > > > > > > > v4: Fix some build warnings reported by kernel test robot > > > > > > > > > > v3: Modify patch #3 to maintain compatibility for memmap=limit{$,#,!}base, > > > > > commented by Mike Rapoport, thank you > > > > > > > > > > v2: Add some new patches to support memmap=limit@base > > > > > > > > > > Tiezhu Yang (4): > > > > > MIPS: Refactor early_parse_mem() to fix mem= parameter > > > > > memblock: Introduce memblock_mem_range_remove_map() > > > > > MIPS: Refactor early_parse_memmap() to fix memmap= parameter > > > > > MIPS: Remove not used variable usermem > > > > > > > > > > arch/mips/kernel/setup.c | 69 ++++++++++++++++++++++-------------------------- > > > > > include/linux/memblock.h | 1 + > > > > > mm/memblock.c | 9 +++++-- > > > > > 3 files changed, 40 insertions(+), 39 deletions(-) > > > > > > > > > > -- > > > > > 2.1.0 > > > > > > > > > > > > > > > -- Sincerely yours, Mike.