On Tue, Nov 24, 2020 at 05:52:50PM +0800, Muchun Song wrote: > If we enable the CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, we can just > disbale PMD page mapping of vmemmap to simplify the code. In this > case, we do not need complex code doing vmemmap page table > manipulation. This is a way to simply the first version of this > patch series. In the future, we can add some code doing page table > manipulation. IIRC, CONFIG_HUGETLB_PAGE_FREE_VMEMMAP was supposed to be enabled by default, right? And we would control whether we __really__ want to this by a boot option, which was disabled by default? If you go for populating the memmap with basepages by checking CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, would not everybody, even the ones that did not enable this by the boot option be affected? -- Oscar Salvador SUSE L3