[PATCH v21 3/5] arm64: kdump: reimplement crashkernel=X

[Leizhen (ThunderTown)]

On 2022/3/17 10:38, Baoquan He wrote:
> On 02/27/22 at 11:07am, Zhen Lei wrote:
>> From: Chen Zhou <chenzhou10 at huawei.com>
>>
>> There are following issues in arm64 kdump:
>> 1. We use crashkernel=X to reserve crashkernel below 4G, which
>> will fail when there is no enough low memory.
>> 2. If reserving crashkernel above 4G, in this case, crash dump
>> kernel will boot failure because there is no low memory available
>               ~~ change it to "get boot failure" or "fail to boot"

OK. I'm going to use "fail to boot".

>> for allocation.
>>
>> To solve these issues, change the behavior of crashkernel=X and
>> introduce crashkernel=X,[high,low]. crashkernel=X tries low allocation
>> in DMA zone, and fall back to high allocation if it fails.
>> We can also use "crashkernel=X,high" to select a region above DMA zone,
>> which also tries to allocate at least 256M in DMA zone automatically.
>> "crashkernel=Y,low" can be used to allocate specified size low memory.
>>
>> Signed-off-by: Chen Zhou <chenzhou10 at huawei.com>
>> Co-developed-by: Zhen Lei <thunder.leizhen at huawei.com>
>> Signed-off-by: Zhen Lei <thunder.leizhen at huawei.com>
> 
> .
> 

-- 
Regards,
  Zhen Lei