x86, numa, acpi, memory-hotplug: make movable_node have higher priority

If users specify the original movablecore=nn@ss boot option, the kernel
will arrange [ss, ss+nn) as ZONE_MOVABLE.  The kernelcore=nn@ss boot
option is similar except it specifies ZONE_NORMAL ranges.

Now, if users specify "movable_node" in kernel commandline, the kernel
will arrange hotpluggable memory in SRAT as ZONE_MOVABLE.  And if users
do this, all the other movablecore=nn@ss and kernelcore=nn@ss options
should be ignored.

For those who don't want this, just specify nothing.  The kernel will
act as before.

Signed-off-by: Tang Chen <[email protected]>
Signed-off-by: Zhang Yanfei <[email protected]>
Reviewed-by: Wanpeng Li <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: "Rafael J . Wysocki" <[email protected]>
Cc: Chen Tang <[email protected]>
Cc: Gong Chen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Lai Jiangshan <[email protected]>
Cc: Larry Woodman <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Liu Jiang <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michal Nazarewicz <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Prarit Bhargava <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Taku Izumi <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Thomas Renninger <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Vasilis Liaskovitis <[email protected]>
Cc: Wen Congyang <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Cc: Yinghai Lu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/page_alloc.c

@@ -5018,9 +5018,33 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 	nodemask_t saved_node_state = node_states[N_MEMORY];
 	unsigned long totalpages = early_calculate_totalpages();
 	int usable_nodes = nodes_weight(node_states[N_MEMORY]);
+	struct memblock_type *type = &memblock.memory;
+
+	/* Need to find movable_zone earlier when movable_node is specified. */
+	find_usable_zone_for_movable();
+
+	/*
+	 * If movable_node is specified, ignore kernelcore and movablecore
+	 * options.
+	 */
+	if (movable_node_is_enabled()) {
+		for (i = 0; i < type->cnt; i++) {
+			if (!memblock_is_hotpluggable(&type->regions[i]))
+				continue;
+
+			nid = type->regions[i].nid;
+
+			usable_startpfn = PFN_DOWN(type->regions[i].base);
+			zone_movable_pfn[nid] = zone_movable_pfn[nid] ?
+				min(usable_startpfn, zone_movable_pfn[nid]) :
+				usable_startpfn;
+		}
+
+		goto out2;
+	}
 
 	/*
-	 * If movablecore was specified, calculate what size of
+	 * If movablecore=nn[KMG] was specified, calculate what size of
 	 * kernelcore that corresponds so that memory usable for
 	 * any allocation type is evenly spread. If both kernelcore
 	 * and movablecore are specified, then the value of kernelcore
@@ -5046,7 +5070,6 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 		goto out;
 
 	/* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */
-	find_usable_zone_for_movable();
 	usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone];
 
 restart:
@@ -5137,6 +5160,7 @@ static void __init find_zone_movable_pfns_for_nodes(void)
 	if (usable_nodes && required_kernelcore > usable_nodes)
 		goto restart;
 
+out2:
 	/* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */
 	for (nid = 0; nid < MAX_NUMNODES; nid++)
 		zone_movable_pfn[nid] =