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Subject: Re: [PATCH v11 5/5] kdump: update Documentation about crashkernel
To:     Dave Young <dyoung@redhat.com>, <catalin.marinas@arm.com>
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From:   chenzhou <chenzhou10@huawei.com>
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Date:   Fri, 28 Aug 2020 09:59:19 +0800
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Hi Catalin,


On 2020/8/19 20:03, Dave Young wrote:
> On 08/18/20 at 03:07pm, chenzhou wrote:
>>
>> On 2020/8/10 14:03, Dave Young wrote:
>>> Hi,
>>>
>>>>> Previously I remember we talked about to use similar logic as X86, but I
>>>>> remember you mentioned on some arm64 platform there could be no low
>>>>> memory at all.  Is this not a problem now for the fallback?  Just be
>>>>> curious, thanks for the update, for the common part looks good.
>>>> Hi Dave,
>>>>
>>>> Did you mean this discuss: https://lkml.org/lkml/2019/12/27/122?
>>> I meant about this reply instead :)
>>> https://lkml.org/lkml/2020/1/16/616
>> Hi Dave,
>>
>> Sorry for not repley in time, I was on holiday last week.
> Hi, no problem, thanks for following up.
>
>> The platform James mentioned may exist for which have no devices and need no low memory.
>> For our arm64 server platform, there are some devices and need low memory.
>>
>> I got it. For the platform with no low memory, reserving crashkernel will  always fail.
>> How about like this:
> I think the question should leave to Catalin or James, I have no
> suggestion about this:)
Any suggestions about this?

Thanks,
Chen Zhou
>
>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>> index a8e34d97a894..4df18c7ea438 100644
>> --- a/arch/arm64/mm/init.c
>> +++ b/arch/arm64/mm/init.c
>> @@ -147,7 +147,7 @@ static void __init reserve_crashkernel(void)
>>         }
>>         memblock_reserve(crash_base, crash_size);
>>  
>> -       if (crash_base >= CRASH_ADDR_LOW_MAX) {
>> +       if (memstart_addr < CRASH_ADDR_LOW_MAX && crash_base >= CRASH_ADDR_LOW_MAX) {
>>                 const char *rename = "Crash kernel (low)";
>>  
>>                 if (reserve_crashkernel_low()) {
>>
>>
>> Thanks,
>> Chen Zhou
>>
>>> Thanks
>>> Dave
>>>
>>>
>>> .
>>>
>>
>
> .
>