On 02/01/18 at 06:23am, Dave Hansen wrote: > On 02/01/2018 06:19 AM, Baoquan He wrote: > > > > I suppose these functions changed here are only called during system > > bootup, namely in paging_init(). Hot-add memory goes in a different > > path, __add_section() -> sparse_add_one_section(), different called > > functions. > > But does this keep those sections that were not present on boot from > being added later? I think it won't. As you can see, the referred functions are only called during init stage. If anyone try to use any of them for later hot-add memory, that will cause problem, lucky there isn't. And this is only used to store the allocated usemap and mem_map for each present section on boot. After that, the usemap_map and map_map pointer array will be freed, they are temporary here. I forget mentioning this in patch log, sorry for bringing confusion. void __init sparse_memory_present_with_active_regions(int nid) void __init memory_present(int nid, unsigned long start, unsigned long end) void __init sparse_init(void) static void __init alloc_usemap_and_memmap(...) static void __init sparse_early_usemaps_alloc_node(...) static void __init sparse_early_mem_maps_alloc_node(...) void __init sparse_mem_maps_populate_node(...) void __init sparse_mem_maps_populate_node(...) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
