lkml.org 
[lkml]   [2021]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v14 11/11] kdump: update Documentation about crashkernel
From
Date


On 2021/2/18 16:40, Baoquan He wrote:
> On 01/30/21 at 03:10pm, Chen Zhou wrote:
>> For arm64, the behavior of crashkernel=X has been changed, which
>> 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 high region above
>> DMA zone, which also tries to allocate at least 256M low memory in
>> DMA zone automatically and "crashkernel=Y,low" can be used to allocate
>> specified size low memory.
>>
>> So update the Documentation.
> Nice document adding which also takes care of x86 code implementation,
> thanks. By the way, maybe you can remove John's 'Tested-by' since it
> doesn't make much sense to test a document patch.
I will remove the Tested-by in next version.
>
> Acked-by: Baoquan He <bhe@redhat.com>
>
>> Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
>> Tested-by: John Donnelly <John.p.donnelly@oracle.com>
>> ---
>> 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/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst
>> index 75a9dd98e76e..0877c76f8015 100644
>> --- a/Documentation/admin-guide/kdump/kdump.rst
>> +++ b/Documentation/admin-guide/kdump/kdump.rst
>> @@ -299,7 +299,16 @@ Boot into System Kernel
>> "crashkernel=64M@16M" tells the system kernel to reserve 64 MB of memory
>> starting at physical address 0x01000000 (16MB) for the dump-capture kernel.
>>
>> - On x86 and x86_64, use "crashkernel=64M@16M".
>> + On x86 use "crashkernel=64M@16M".
>> +
>> + On x86_64, use "crashkernel=X" to select a region under 4G first, and
>> + fall back to reserve region above 4G. And go for high allocation
>> + directly if the required size is too large.
>> + We can also use "crashkernel=X,high" to select a region above 4G, which
>> + also tries to allocate at least 256M below 4G automatically and
>> + "crashkernel=Y,low" can be used to allocate specified size low memory.
>> + Use "crashkernel=Y@X" if you really have to reserve memory from specified
>> + start address X.
>>
>> On ppc64, use "crashkernel=128M@32M".
>>
>> @@ -316,8 +325,15 @@ Boot into System Kernel
>> kernel will automatically locate the crash kernel image within the
>> first 512MB of RAM if X is not given.
>>
>> - On arm64, use "crashkernel=Y[@X]". Note that the start address of
>> - the kernel, X if explicitly specified, must be aligned to 2MiB (0x200000).
>> + On arm64, use "crashkernel=X" to try low allocation in DMA zone and
>> + fall back to high allocation if it fails.
>> + We can also use "crashkernel=X,high" to select a high region above
>> + DMA zone, which also tries to allocate at least 256M low memory in
>> + DMA zone automatically.
>> + "crashkernel=Y,low" can be used to allocate specified size low memory.
>> + Use "crashkernel=Y@X" if you really have to reserve memory from
>> + specified start address X. Note that the start address of the kernel,
>> + X if explicitly specified, must be aligned to 2MiB (0x200000).
>>
>> Load the Dump-capture Kernel
>> ============================
>> 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
>> @@ -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
>> + 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.
>> + 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.
>> + This one let user to specify a low range in DMA zone for
>> + crash dump kernel.
>> cryptomgr.notests
>> [KNL] Disable crypto self-tests
>>
>> --
>> 2.20.1
>>
> .
>

\
 
 \ /
  Last update: 2021-02-20 04:27    [W:0.109 / U:6.640 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site