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Subject: Re: [RFC PATCH v3 1/2] mempinfd: Add new syscall to provide memory
 pin
To:     Arnd Bergmann <arnd@kernel.org>
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        Zhangfei Gao <zhangfei.gao@linaro.org>,
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From:   Zhou Wang <wangzhou1@hisilicon.com>
Message-ID: <753db746-292c-4f1d-c79f-9a7282a19ba2@hisilicon.com>
Date:   Tue, 9 Feb 2021 17:27:30 +0800
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On 2021/2/8 5:51, Arnd Bergmann wrote:
> On Sun, Feb 7, 2021 at 9:18 AM Zhou Wang <wangzhou1@hisilicon.com> wrote:
> 
>> diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
>> index cccfbbe..3f49529 100644
>> --- a/arch/arm64/include/asm/unistd32.h
>> +++ b/arch/arm64/include/asm/unistd32.h
>> @@ -891,6 +891,8 @@ __SYSCALL(__NR_faccessat2, sys_faccessat2)
>>  __SYSCALL(__NR_process_madvise, sys_process_madvise)
>>  #define __NR_epoll_pwait2 441
>>  __SYSCALL(__NR_epoll_pwait2, compat_sys_epoll_pwait2)
>> +#define __NR_mempinfd 442
>> +__SYSCALL(__NR_mempinfd, sys_mempinfd)
> 
> This adds a compat syscall for 32-bit tasks running on arm64 without adding
> the same for the native arch/arm syscall table. Those two need to always
> stay synchronized. In fact, new system call should ideally get assigned
> on all architectures at the same time, with the same number (or +110
> on arch/alpha).

Thank for pointing out this. I use an ARM64 machine to test, so
currently only add it for ARM64 :)

Best,
Zhou

> 
>          Arnd
> 
> .
>