Re: [PATCH v14 11/11] kdump: update Documentation about crashkernel

From: Randy Dunlap
Date: Sat Jan 30 2021 - 12:54:49 EST


Hi--

On 1/29/21 11:10 PM, Chen Zhou wrote:
> ---
> Documentation/admin-guide/kdump/kdump.rst | 22 ++++++++++++++++---
> .../admin-guide/kernel-parameters.txt | 11 ++++++++--
> 2 files changed, 28 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a10b545c2070..908e5c8b61ba 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt

All of the "arm64" instances in [square brackets] should be "ARM64".

> @@ -738,6 +738,9 @@
> [KNL, X86-64] Select a region under 4G first, and
> fall back to reserve region above 4G when '@offset'
> hasn't been specified.
> + [KNL, arm64] Try low allocation in DMA zone and fall back

here

> + to high allocation if it fails when '@offset' hasn't been
> + specified.
> See Documentation/admin-guide/kdump/kdump.rst for further details.
>
> crashkernel=range1:size1[,range2:size2,...][@offset]
> @@ -754,6 +757,8 @@
> Otherwise memory region will be allocated below 4G, if
> available.
> It will be ignored if crashkernel=X is specified.
> + [KNL, arm64] range in high memory.

here

> + Allow kernel to allocate physical memory region from top.
> crashkernel=size[KMG],low
> [KNL, X86-64] range under 4G. When crashkernel=X,high
> is passed, kernel could allocate physical memory region
> @@ -762,13 +767,15 @@
> 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
> - at least 256M below 4G automatically.
> + least 256M below 4G automatically.
> This one let user to specify own low range under 4G
> for second kernel instead.
> 0: to disable low allocation.
> It will be ignored when crashkernel=X,high is not used
> or memory reserved is below 4G.
> -
> + [KNL, arm64] range in low memory.

here

> + This one let user to specify a low range in DMA zone for
> + crash dump kernel.


Thanks.

--
~Randy