[PATCH v4 0/3] arm64: support page mapping percpu first chunk allocator

Kefeng Wang wangkefeng.wang at huawei.com
Fri Oct 8 06:33:18 PDT 2021



On 2021/9/28 15:48, Kefeng Wang wrote:
> Hi Catalin and Andrew, kindly ping again, any comments, thanks.

Looks no more comments, Catalin and Andrew, ping again, any one of you
could merge this patchset, many thanks.

> 
> On 2021/9/10 13:33, Kefeng Wang wrote:
>> Percpu embedded first chunk allocator is the firstly option, but it
>> could fails on ARM64, eg,
>>    "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 
>> 0x781fefff0000"
>>    "percpu: max_distance=0x600000540000 too large for vmalloc space 
>> 0x7dffb7ff0000"
>>    "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 
>> 0x5dffb7ff0000"
>>
>> then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 
>> pcpu_get_vm_areas+0x488/0x838",
>> even the system could not boot successfully.
>>
>> Let's implement page mapping percpu first chunk allocator as a fallback
>> to the embedding allocator to increase the robustness of the system.
>>
>> Also fix a crash when both NEED_PER_CPU_PAGE_FIRST_CHUNK and 
>> KASAN_VMALLOC enabled.
>>
>> Tested on ARM64 qemu with cmdline "percpu_alloc=page" based on v5.14.
>>
>> V4:
>> - add ACK/RB
>> - address comments about patch1 from Catalin
>> - add Greg and Andrew into list suggested by Catalin
>>
>> v3:
>> - search for a range that fits instead of always picking the end from
>>    vmalloc area suggested by Catalin.
>> - use NUMA_NO_NODE to avoid "virt_to_phys used for non-linear address:"
>>    issue in arm64 kasan_populate_early_vm_area_shadow().
>> - add Acked-by: Marco Elver <elver at google.com> to patch v3
>>
>> V2:
>> - fix build error when CONFIG_KASAN disabled, found by lkp at intel.com
>> - drop wrong __weak comment from kasan_populate_early_vm_area_shadow(),
>>    found by Marco Elver <elver at google.com>
>>
>> Kefeng Wang (3):
>>    vmalloc: Choose a better start address in vm_area_register_early()
>>    arm64: Support page mapping percpu first chunk allocator
>>    kasan: arm64: Fix pcpu_page_first_chunk crash with KASAN_VMALLOC
>>
>>   arch/arm64/Kconfig         |  4 ++
>>   arch/arm64/mm/kasan_init.c | 16 ++++++++
>>   drivers/base/arch_numa.c   | 82 +++++++++++++++++++++++++++++++++-----
>>   include/linux/kasan.h      |  6 +++
>>   mm/kasan/init.c            |  5 +++
>>   mm/vmalloc.c               | 19 ++++++---
>>   6 files changed, 116 insertions(+), 16 deletions(-)
>>



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