On 2022/6/13 14:38, Anshuman Khandual wrote: > > > 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. > I will add this in patch v4. >> >>>> >>>> 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. I will add this paragraph in patch v4. > >> >>>> >>>> Signed-off-by: Zhou Guanghui <zhouguanghui1@xxxxxxxxxx> >>>> Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> >>>> --- >>>> 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. > I'll add it to the comment in patch v4. >> >>>> +#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 ? > In my opinion, the purpose of adding INIT_MEMBLOCK_MEMORY_REGTIONS is to specify a larger size on different platforms. In the future, the base value of INIT_MEMBLOCK_REGTIONS is adjusted to a larger value (for example, 256). On the arm64 platform, it is not necessary to adjust (256 * 8) INIT_MEMBLOCK_MEMORY_REGTIONS. Thanks!
