Re: [PATCH v4 1/4] MIPS: Refactor early_parse_mem() to fix mem= parameter

Thomas Bogendoerfer
2022-03-04T15:14:09Z

On Tue, Mar 01, 2022 at 12:28:58PM +0800, Tiezhu Yang wrote:
> According to Documentation/admin-guide/kernel-parameters.txt,
> the kernel command-line parameter mem= means "Force usage of
> a specific amount of memory", but when add "mem=3G" to the
> command-line, kernel boot hangs in sparse_init().
>
> This commit is similar with the implementation of the other
> archs such as arm64, powerpc and riscv, refactor the function
> early_parse_mem() and then use memblock_enforce_memory_limit()
> to limit the memory size.
>
> With this patch, when add "mem=3G" to the command-line, the
> kernel boots successfully, we can see the following messages:

unfortunately this patch would break platforms without memory detection,
which simply use mem=32M for memory configuration. Not sure how many
rely on this mechanism. If we can make sure nobody uses it, I'm fine
with your patch.

Thomas.

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