Ho Christian, On Mon, May 04, 2020 at 04:50:06PM +0200, Christian Borntraeger wrote: > Mike, > commit 51a2f644fd020d5f090044825c388444d11029d ("mm: free_area_init: allow defining max_zone_pfn in descending order") > does increase the memory use on s390 (e.g. 700 MB vs.1.8 GB). > > Something is odd in this patch. Any idea? Yeah, this patch is buggy. In short, it breaks zone size calculation on s390 and some other architectures. I've just replied at [1] with more details and a fix. [1] https://lore.kernel.org/linux-mm/20200504153901.GM14260@xxxxxxxxxx/ -- Sincerely yours, Mike.