linux-master/mm/sparse.c

65 	struct mem_section *section = NULL;
70 		section = kzalloc_node(array_size, GFP_KERNEL, nid);
72 		section = memblock_alloc_node(array_size, SMP_CACHE_BYTES,
74 		if (!section)
79 	return section;
85 	struct mem_section *section;
88 	 * An existing section is possible in the sub-section hotplug
90 	 * the existing section.
97 	section = sparse_index_alloc(nid);
98 	if (!section)
101 	mem_section[root] = section;
114  * mem_map, we use section_mem_map to store the section's NUMA
123 static inline int sparse_early_nid(struct mem_section *section)
125 	return (section->section_mem_map >> SECTION_NID_SHIFT);
232 		unsigned long section = pfn_to_section_nr(pfn);
235 		sparse_index_init(section, nid);
236 		set_section_nid(section, nid);
238 		ms = __nr_to_section(section);
242 			__section_mark_present(ms, section);
340 	 * page being freed and making a section unremovable while
342 	 * a pgdat can prevent a section being removed. If section A
343 	 * contains a pgdat and section B contains the usemap, both
345 	 * from the same section as the pgdat where possible to avoid
389 		pr_info("node %d must be removed before remove section %ld\n",
395 	 * Some platforms allow un-removable section because they will just
397 	 * Just notify un-removable section's number here.
463 	 * and we want it to be properly aligned to the section size - this is
556  * for each and record the physical to section mapping.
669 				"section already deactivated (%#lx + %ld)\n",
737 		 * When this function is called, the removing section is
739 		 * from page allocator. If removing section's memmap is placed
740 		 * on the same section, it must not be freed.
769  * 1. deactivation of a partial hot-added section (only possible in
771  *      a) section was present at memory init.
772  *      b) section was hot-added post memory init.
773  * 2. deactivation of a complete hot-added section.
774  * 3. deactivation of a complete section from memory init.
797 		 * Mark the section invalid so that valid_section()
804 		 * When removing an early section, the usage map is kept (as the
806 		 * will be re-used when re-adding the section - which is then no
807 		 * longer an early section. If the usage map is PageReserved, it
857 	 * referenced.  If we hot-add memory into such a section then we
874  * sparse_add_section - add a memory section, or populate an existing one
875  * @nid: The node to add section on
877  * @nr_pages: number of pfns to add in the section
883  * Note that only VMEMMAP supports sub-section aligned hotplug,
920 	/* Align memmap to section boundary in the subsection case */