Re: [PATCH v12 6/9] arm64: kdump: reimplement crashkernel=X

[chenzhou]

On 2020/10/6 1:16, Catalin Marinas wrote:
> On Mon, Sep 07, 2020 at 09:47:42PM +0800, Chen Zhou wrote:
>> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
>> index 53acbeca4f57..1b24072f2bae 100644
>> --- a/arch/arm64/kernel/setup.c
>> +++ b/arch/arm64/kernel/setup.c
>> @@ -238,7 +238,18 @@ static void __init request_standard_resources(void)
>>  		    kernel_data.end <= res->end)
>>  			request_resource(res, &kernel_data);
>>  #ifdef CONFIG_KEXEC_CORE
>> -		/* Userspace will find "Crash kernel" region in /proc/iomem. */
>> +		/*
>> +		 * Userspace will find "Crash kernel" or "Crash kernel (low)"
>> +		 * region in /proc/iomem.
>> +		 * In order to distinct from the high region and make no effect
>> +		 * to the use of existing kexec-tools, rename the low region as
>> +		 * "Crash kernel (low)".
>> +		 */
>> +		if (crashk_low_res.end && crashk_low_res.start >= res->start &&
>> +				crashk_low_res.end <= res->end) {
>> +			crashk_low_res.name = "Crash kernel (low)";
>> +			request_resource(res, &crashk_low_res);
>> +		}
> With the changes in this series (including the above), how do the
> current kexec-tools behave? Do they pick just the high region and the
> loaded kernel will subsequently fail to boot?
Yes，just pick the high region and will boot fail if low memory is needed.

Thanks,
Chen Zhou
>