On Thu, May 12, 2022 at 09:36:15AM +0200, David Hildenbrand wrote: > On 09.05.22 08:27, Muchun Song wrote: > > Optimizing HugeTLB vmemmap pages is not compatible with allocating memmap on > > hot added memory. If "hugetlb_free_vmemmap=on" and > > memory_hotplug.memmap_on_memory" are both passed on the kernel command line, > > optimizing hugetlb pages takes precedence. > > Why? > Because both two features are not compatible since hugetlb_free_vmemmap cannot optimize the vmemmap pages allocated from alternative allocator (when memory_hotplug.memmap_on_memory=1). So when the feature of hugetlb_free_vmemmap is introduced, I made hugetlb_free_vmemmap take precedence. BTW, I have a plan to remove this restriction, I'll post it out ASAP. Thanks.