Re: [RFC] memmap: introduce cmdline parameter "memmap=nn[KMG]$" without start addr

[H. Peter Anvin]

On June 23, 2022 7:06:36 AM PDT, Dave Hansen <dave.hansen@xxxxxxxxx> wrote:
>On 6/22/22 23:24, lizhe.67@xxxxxxxxxxxxx wrote:
>> In our scenario, we need reserve or alloc large continous memory like
>> 256M in machine which have different memory specification at just
>> boot phase for a user land process.
>
>Just marking the memory reserved doesn't do any good by itself.  There
>must be some *other* kernel code to find this reserved area and make it
>available to userspace.
>
>It seems kinda silly to add this to the kernel without also adding the
>other half of the solution.  Plus, we don't really even know what this
>is for.  Are there other, better solutions?  I certainly can't offer any
>because this changelog did not provide a full picture of the problem
>this solves.

Don't we already have a large contiguous physical memory allocator for this reason (misdesigned hardware?)