+/**
+ * struct memory_group - a logical group of memory blocks
+ * @nid: The node id for all memory blocks inside the memory group.
+ * @blocks: List of all memory blocks belonging to this memory group.
+ * @present_kernel_pages: Present (online) memory outside ZONE_MOVABLE of this
+ * memory group.
+ * @present_movable_pages: Present (online) memory in ZONE_MOVABLE of this
+ * memory group.
+ * @is_dynamic: The memory group type: static vs. dynamic
+ * @s.max_pages: Valid with &memory_group.is_dynamic == false. The maximum
+ * number of pages we'll have in this static memory group.
+ * @d.unit_pages: Valid with &memory_group.is_dynamic == true. Unit in pages
+ * in which memory is added/removed in this dynamic memory group.
+ * This granularity defines the alignment of a unit in physical
+ * address space; it has to be at least as big as a single
+ * memory block.
+ *
+ * A memory group logically groups memory blocks; each memory block
+ * belongs to at most one memory group. A memory group corresponds to
+ * a memory device, such as a DIMM or a NUMA node, which spans multiple
+ * memory blocks and might even span multiple non-contiguous physical memory
+ * ranges.
+ *
+ * Modification of members after registration is serialized by memory
+ * hot(un)plug code.
+ */
+struct memory_group {
+ int nid;
+ struct list_head memory_blocks;
+ unsigned long present_kernel_pages;
+ unsigned long present_movable_pages;
+ bool is_dynamic;
+ union {
+ struct {
+ unsigned long max_pages;
+ } s;
+ struct {
+ unsigned long unit_pages;
+ } d;
+ };
+};
+