On 3/21/22 8:29AM, John Donnelly wrote:
On 2/26/22 9:07 PM, Zhen Lei wrote:
From: Chen Zhou <chenzhou10@xxxxxxxxxx>
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.
" Not enough "
2. If reserving crashkernel above 4G, in this case, crash dump
kernel will boot failure because there is no low memory available
for allocation.
We can't have a "boot failure". If the requested reservation
can not be met, the kdump configuration is not setup.
I think you misread this. Without these patches, if only high memory is
reserved for the crash kernel, then the crash kernel will fail to boot.
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.
Is there going to be documentation on what values certain Arm platforms
are going to use this on ?
Signed-off-by: Chen Zhou <chenzhou10@xxxxxxxxxx>
Co-developed-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
