Re: [PATCH] kho: Skip zero-sized bootmem areas

[Pratyush Yadav]

Hi Chen,

On Tue, Oct 27 2026, Chen Pei wrote:

>> Do you see zero sized lowmem or global scratch in practice? If yes,
>> how? What's your setup?
>
> Yes. Enabling KHO for riscv64 gave me three cases. They differ in which
> size ends up 0 and in what it costs, and all three are measured:
[...]
>
>> Note that I already fixed this for per-node areas since those do end
>> up with no allocations with movable_node set [0].
>
> That one covers the per-node loop only; lowmem and global are still
> unconditional in linux-next today, which is what cases 1, 2 and 3 above
> are about. Is there anything I have not considered here? Please point
> it out and I will follow up accordingly.

Mike sent out [0] recently which should fix this problem. Please take a
look at that, and see if it works for you.

[0] https://lore.kernel.org/kexec/20261103-kho-bootmem-sizing-v1-1-45aa74098f34@xxxxxxxxxx/

-- 
Regards,
Pratyush Yadav