Hi, Arnd, On Fri, Jun 17, 2022 at 11:42 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Fri, Jun 17, 2022 at 4:58 PM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote: > > > > Add sparse memory vmemmap support for LoongArch. SPARSEMEM_VMEMMAP > > uses a virtually mapped memmap to optimise pfn_to_page and page_to_pfn > > operations. This is the most efficient option when sufficient kernel > > resources are available. > > I have not looked at this in detail, but from a high-level perspective, it > seems very similar to the corresponding code in arch/arm64 and arch/x86. > > Can you try to merge the three copies into a generic helper and add that > to mm/sparse-vmemmap.c? If this does not work, can you describe in the > changelog text why these have to be architecture specific? It is difficult to merge, because LoongArch needs to call pud_init(), pmd_init() and other similar things which are unnecessary on ARM64 and X86. Huacai > > Arnd
