[PATCH v23 6/6] docs: kdump: Update the crashkernel description for arm64

Zhen Lei
2022-05-05T09:21:41Z

Now arm64 has added support for "crashkernel=X,high" and
"crashkernel=Y,low". Unlike x86, crash low memory is not allocated if
"crashkernel=Y,low" is not specified.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
---
Documentation/admin-guide/kernel-parameters.txt | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3f1cc5e317ed4a5..aa44c61114aa4b8 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -808,7 +808,7 @@
Documentation/admin-guide/kdump/kdump.rst for an example.

crashkernel=size[KMG],high
- [KNL, X86-64] range could be above 4G. Allow kernel
+ [KNL, X86-64, ARM64] range could be above 4G. Allow kernel
to allocate physical memory region from top, so could
be above 4G if system have more than 4G ram installed.
Otherwise memory region will be allocated below 4G, if
@@ -821,7 +821,7 @@
that require some amount of low memory, e.g. swiotlb
requires at least 64M+32K low memory, also enough extra
low memory is needed to make sure DMA buffers for 32-bit
- devices won't run out. Kernel would try to allocate at
+ devices won't run out. Kernel would try to allocate
at least 256M below 4G automatically.
This one let user to specify own low range under 4G
for second kernel instead.
@@ -829,6 +829,11 @@
It will be ignored when crashkernel=X,high is not used
or memory reserved is below 4G.

+ [KNL, ARM64] range in low memory.
+ This one let user to specify a low range in DMA zone for
+ crash dump kernel.
+ It will be ignored when crashkernel=X,high is not used.
+
cryptomgr.notests
[KNL] Disable crypto self-tests

--
2.25.1