Re: [PATCH 0/3] ARM: Use generic interface to simplify crashkernel reservation

Jinjie Ruan
2024-07-09T11:06:14Z

On 2024/7/9 18:39, Baoquan He wrote:
> On 07/09/24 at 05:50pm, Jinjie Ruan wrote:
>>
>>
>> On 2024/7/9 17:29, Baoquan He wrote:
>>> On 07/08/24 at 09:33pm, Jinjie Ruan wrote:
>>>> Currently, x86, arm64, riscv and loongarch has been switched to generic
>>>> crashkernel reservation. Also use generic interface to simplify crashkernel
>>>> reservation for arm32, and fix two bugs by the way.
>>>
>>> I am not sure if this is a good idea. I added the generic reservation
>>> itnerfaces for ARCH which support crashkernel=,high|low and normal
>>> crashkernel reservation, with this, the code can be simplified a lot.
>>> However, arm32 doesn't support crashkernel=,high, I am not sure if it's
>>> worth taking the change, most importantly, if it will cause
>>> misunderstanding or misoperation.
>>
>> Yes, arm32 doesn't support crashkernel=,high.
>>
>> However, a little enhancement to the generic code (please see the first
>> patch), the generic reservation interfaces can also be applicable to
>> architectures that do not support "high" such as arm32, and it can also
>> simplify the code (please see the third patch).
>
> Yeah, I can see the code is simplified. When you specified
> 'crashkernel=xM,high', do you think what should be warn out? Because
> it's an unsupported syntax on arm32, we should do something to print out
> appropriate message.

Yes, you are right! In this patch it will print "crashkernel high memory
reservation failed." message and out for arm32 if you specify
'crashkernel=xM,high because "CRASH_ADDR_LOW_MAX" and
"CRASH_ADDR_HIGH_MAX" is identical for arm32. And it should also warn
out for other similar architecture.

>
>