Hi,

On Thu, Nov 11, 2021 at 03:33:29PM +0800, Mark-PK Tsai wrote:

Hi,

The lts kernel also have this issue. (we use 5.4-lts kernel.)
Currently we patch our custom kernel to select CONFIG_HOLES_IN_ZONE for arch arm.
But I think the formal solution should backport to lts.

Would you help to backport this patch series? (including the below commit)

There were a couple of changes between 5.4 and this set, so you'd need to
"apply" the first two patches to arm::free_unused_memmap(). Other than
that, I don't see any pitfalls here.

Feel free to CC me when you post the backported series.
 

(024591f9a6e0 arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM)

Thanks!

-- 
Sincerely yours,
Mike.