Re: [PATCH] mm/memblock: only mark/clear KHO scratch memory when needed

[Usama Arif]

On 26/11/2025 10:40, Kiryl Shutsemau wrote:
> On Wed, Nov 26, 2025 at 07:20:51AM +0000, Usama Arif wrote:
>> @@ -1126,8 +1126,11 @@ int __init_memblock memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t
>>   */
>>  __init int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size)
>>  {
>> -	return memblock_setclr_flag(&memblock.memory, base, size, 1,
>> -				    MEMBLOCK_KHO_SCRATCH);
>> +	if (IS_ENABLED(CONFIG_MEMBLOCK_KHO_SCRATCH) && is_kho_boot())
> 
> It makes me wounder why CONFIG_MEMBLOCK_KHO_SCRATCH exists? It seems to
> be a proxy for CONFIG_KEXEC_HANDOVER which is the only option that
> selects it and does it always.
> 
> Can we make s/CONFIG_MEMBLOCK_KHO_SCRATCH/CONFIG_KEXEC_HANDOVER/ and
> remove IS_ENABLED() from this check? Just is_kho_boot() is enough.
> 
> 

Thats a very good point! I imagine it might have been for maybe debug purposes?

Looking at the code, CONFIG_MEMBLOCK_KHO_SCRATCH shouldnt be needed. I guess
this might be a good time to clean it up. If Mike is happy for it to be replaced
with CONFIG_KEXEC_HANDOVER (and removed where needed), happy to send that
for review instead of this.

Thanks
Usama