Re: [PATCH v4] arm64: mm: Populate vmemmap/linear at the page level for hotplugged sections

On 2025/1/8 18:11, Anshuman Khandual wrote:

Just wondering why not start with PUD level itself ? Although SUBSECTION_SHIFT might never reach the PUD level but this will help keep the flags calculations bit simple and ready for all future changes.

I suppose that it's because these are significantly larger than 2M, whereas Catalin assumed SUBSECTION_SIZE would not increase? His comment: "should cover any changes to SUBSECTION_SHIFT making it *smaller* than 2MB. "

flags = 0; if (SUBSECTION_SHIFT < PUD_SHIFT) flags |= NO_PUD_BLOCK_MAPPINGS; if (SUBSECTION_SHIFT < CONT_PMD_SHIFT) flags |= NO_PMD_CONT_MAPPINGS;