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 186C2C43334 for ; Mon, 13 Jun 2022 06:38:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236746AbiFMGi5 (ORCPT ); Mon, 13 Jun 2022 02:38:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229638AbiFMGi4 (ORCPT ); Mon, 13 Jun 2022 02:38:56 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 107BE2DE2 for ; Sun, 12 Jun 2022 23:38:54 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5EFDD6E; Sun, 12 Jun 2022 23:38:53 -0700 (PDT) Received: from [10.163.38.134] (unknown [10.163.38.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DB2683F792; Sun, 12 Jun 2022 23:38:50 -0700 (PDT) Message-ID: <2a492d62-8ce0-effe-b854-d0b58762be23@arm.com> Date: Mon, 13 Jun 2022 12:08:50 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v3] memblock,arm64: Expand the static memblock memory table Content-Language: en-US To: Zhouguanghui , "akpm@linux-foundation.org" , "rppt@kernel.org" , "will@kernel.org" Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" , "xuqiang (M)" References: <20220527091832.63489-1-zhouguanghui1@huawei.com> From: Anshuman Khandual In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/13/22 11:33, Zhouguanghui wrote: > 在 2022/6/7 14:43, Anshuman Khandual 写道: >> Hello Zhou, >> >> On 5/27/22 14:48, Zhou Guanghui wrote: >>> In a system using HBM, a multi-bit ECC error occurs, and the BIOS >>> will mark the corresponding area (for example, 2 MB) as unusable. >>> When the system restarts next time, these areas are not reported >>> or reported as EFI_UNUSABLE_MEMORY. Both cases lead to an increase >>> in the number of memblocks, whereas EFI_UNUSABLE_MEMORY leads to a >>> larger number of memblocks. >>> >>> For example, if the EFI_UNUSABLE_MEMORY type is reported: >>> ... >>> memory[0x92] [0x0000200834a00000-0x0000200835bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0 >>> memory[0x93] [0x0000200835c00000-0x0000200835dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4 >>> memory[0x94] [0x0000200835e00000-0x00002008367fffff], 0x0000000000a00000 bytes on node 7 flags: 0x0 >>> memory[0x95] [0x0000200836800000-0x00002008369fffff], 0x0000000000200000 bytes on node 7 flags: 0x4 >>> memory[0x96] [0x0000200836a00000-0x0000200837bfffff], 0x0000000001200000 bytes on node 7 flags: 0x0 >>> memory[0x97] [0x0000200837c00000-0x0000200837dfffff], 0x0000000000200000 bytes on node 7 flags: 0x4 >>> memory[0x98] [0x0000200837e00000-0x000020087fffffff], 0x0000000048200000 bytes on node 7 flags: 0x0 >>> memory[0x99] [0x0000200880000000-0x0000200bcfffffff], 0x0000000350000000 bytes on node 6 flags: 0x0 >>> memory[0x9a] [0x0000200bd0000000-0x0000200bd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4 >>> memory[0x9b] [0x0000200bd0200000-0x0000200bd07fffff], 0x0000000000600000 bytes on node 6 flags: 0x0 >>> memory[0x9c] [0x0000200bd0800000-0x0000200bd09fffff], 0x0000000000200000 bytes on node 6 flags: 0x4 >>> memory[0x9d] [0x0000200bd0a00000-0x0000200fcfffffff], 0x00000003ff600000 bytes on node 6 flags: 0x0 >>> memory[0x9e] [0x0000200fd0000000-0x0000200fd01fffff], 0x0000000000200000 bytes on node 6 flags: 0x4 >>> memory[0x9f] [0x0000200fd0200000-0x0000200fffffffff], 0x000000002fe00000 bytes on node 6 flags: 0x0 >>> ... >> >> Although this patch did not mention about a real world system requiring >> this support, as been reported on the thread, Ampere Altra does seem to >> get benefited. Regardless, it's always better to describe platform test >> scenarios in more detail. >> > > I encountered this scenario on Huawei Ascend ARM64 SoC. Please do mention that in the commit message. > >>> >>> The EFI memory map is parsed to construct the memblock arrays before >>> the memblock arrays can be resized. As the result, memory regions >>> beyond INIT_MEMBLOCK_REGIONS are lost. >>> >>> Allow overriding memblock.memory array size with architecture defined >>> INIT_MEMBLOCK_MEMORY_REGIONS and make arm64 to set >>> INIT_MEMBLOCK_MEMORY_REGIONS to 1024 when CONFIG_EFI is enabled. >> >> Right, but first this needs to mention that INIT_MEMBLOCK_MEMORY_REGIONS >> (new macro) is being added to replace INIT_MEMBLOCK_REGIONS, representing >> max memory regions in the memblock. Platform override comes afterwards. >> > > Add a paragraph before the description,like this? > > Add a new macro INIT_MEMBLOCK_MEMORY_REGTIONS to replace > INIT_MEMBLOCK_REGTIONS to define the size of the static memblock.memory > array. Right. > >>> >>> Signed-off-by: Zhou Guanghui >>> Acked-by: Mike Rapoport >>> --- >>> arch/arm64/include/asm/memory.h | 9 +++++++++ >>> mm/memblock.c | 14 +++++++++----- >>> 2 files changed, 18 insertions(+), 5 deletions(-) >>> >>> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h >>> index 0af70d9abede..eda61c0389c4 100644 >>> --- a/arch/arm64/include/asm/memory.h >>> +++ b/arch/arm64/include/asm/memory.h >>> @@ -364,6 +364,15 @@ void dump_mem_limit(void); >>> # define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1) >>> #endif >>> >>> +/* >>> + * memory regions which marked with flag MEMBLOCK_NOMAP may divide a continuous >>> + * memory block into multiple parts. As a result, the number of memory regions >>> + * is large. >>> + */ >> >> As mentioned in the previous version's thread, >> >> This comment needs be more specific about this increased static array size, being >> applicable ONLY for MEMBLOCK_NOMAP regions on EFI system with EFI_UNUSABLE_MEMORY >> tagging/flag support. >> > > EFI_UNUSABLE_MEMORY is only one type of the MEMBLOCK_NOMAP region, as > shown in the is_usable_memory function. However, However, I currently > have too many memblocks due to this flag. Okay, but adding EFI_UNUSABLE_MEMORY context in that comment will be helpful. > >>> +#ifdef CONFIG_EFI >>> +#define INIT_MEMBLOCK_MEMORY_REGIONS 1024 >> >> Although 1024 seems adequate as compared to 128 memory regions in the memblock to >> handle such error scenarios, but a co-relation with INIT_MEMBLOCK_REGIONS would >> be preferred similar to when INIT_MEMBLOCK_RESERVED_REGIONS gets overridden. This >> avoid a precedence when random numbers could get assigned in other archs later on. >> >> $git grep INIT_MEMBLOCK_RESERVED_REGIONS arch/ >> arch/arm64/include/asm/memory.h:# define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1) >> arch/loongarch/include/asm/sparsemem.h:#define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS) >> >> Something like >> >> #define INIT_MEMBLOCK_MEMORY_REGIONS (INIT_MEMBLOCK_REGIONS * 8) >> > > I don't think this is necessary because INIT_MEMBLOCK_REGIONS is not > configurable. The newly added INIT_MEMBLOCK_MEMORY_REGIONS macro is > customized for each platform. Even an existing macro INIT_MEMBLOCK_RESERVED_REGIONS still depends on INIT_MEMBLOCK_REGIONS (arm64, loongarch) ? The point being, although INIT_MEMBLOCK_REGIONS is not configurable, it still does provide enough base value, as compared to defining a random number in platforms which will override INIT_MEMBLOCK_MEMORY_REGIONS. What is your concern in making it dependent on INIT_MEMBLOCK_REGIONS ?