Re: [PATCH v4 0/4] MIPS: Modify mem= and memmap= parameter

[Tiezhu Yang <yangtiezhu@loongson.cn>]

On 03/01/2022 05:55 PM, Mike Rapoport wrote:
> Hi,
>
> On Tue, Mar 01, 2022 at 12:28:57PM +0800, Tiezhu Yang wrote:
>> In the current code, the kernel command-line parameter mem= and memmap=
>> can not work well on MIPS, this patchset refactors the related code to
>> fix them.
>>
>> For kdump on MIPS, if the users want to limit the memory region for the
>> capture kernel to avoid corrupting the memory image of the panic kernel,
>> use the parameter memmap=limit@base is the proper way, I will submit a
>> patch to use memmap=limit@base for kexec-tools after this patchset is
>> applied.
>
> Sorry, apparently I misread the prevoius version.
> What's wrong with the current implementation of mem=limit@base for the
> kdump case?

In the current code, without this patchset, kernel boot hangs when add
mem=3G, mem=3G@64M or memmap=3G@64M to the command-line, it means that
the parameter mem= and memmap= have bug on mips.

Thanks,
Tiezhu

>
>> v4: Fix some build warnings reported by kernel test robot
>>
>> v3: Modify patch #3 to maintain compatibility for memmap=limit{$,#,!}base,
>>     commented by Mike Rapoport, thank you
>>
>> v2: Add some new patches to support memmap=limit@base
>>
>> Tiezhu Yang (4):
>>   MIPS: Refactor early_parse_mem() to fix mem= parameter
>>   memblock: Introduce memblock_mem_range_remove_map()
>>   MIPS: Refactor early_parse_memmap() to fix memmap= parameter
>>   MIPS: Remove not used variable usermem
>>
>>  arch/mips/kernel/setup.c | 69 ++++++++++++++++++++++--------------------------
>>  include/linux/memblock.h |  1 +
>>  mm/memblock.c            |  9 +++++--
>>  3 files changed, 40 insertions(+), 39 deletions(-)
>>
>> --
>> 2.1.0
>>
>