mm/memory_hotplug: memory group aware "auto-movable" online policy

Use memory groups to improve our "auto-movable" onlining policy:

1. For static memory groups (e.g., a DIMM), online a memory block MOVABLE
   only if all other memory blocks in the group are either MOVABLE or could
   be onlined MOVABLE. A DIMM will either be MOVABLE or not, not a mixture.

2. For dynamic memory groups (e.g., a virtio-mem device), online a
   memory block MOVABLE only if all other memory blocks inside the
   current unit are either MOVABLE or could be onlined MOVABLE. For a
   virtio-mem device with a device block size with 512 MiB, all 128 MiB
   memory blocks wihin a 512 MiB unit will either be MOVABLE or not, not
   a mixture.

We have to pass the memory group to zone_for_pfn_range() to take the
memory group into account.

Note: for now, there seems to be no compelling reason to make this
behavior configurable.

Link: https://lkml.kernel.org/r/20210806124715.17090-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hui Zhu <teawater@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 8 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index a1082013e10c..b699ddc42693 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -182,7 +182,8 @@ static int memory_block_online(struct memory_block *mem)
 	struct zone *zone;
 	int ret;
 
-	zone = zone_for_pfn_range(mem->online_type, mem->nid, start_pfn, nr_pages);
+	zone = zone_for_pfn_range(mem->online_type, mem->nid, mem->group,
+				  start_pfn, nr_pages);
 
 	/*
 	 * Although vmemmap pages have a different lifecycle than the pages
@@ -379,12 +380,13 @@ static ssize_t phys_device_show(struct device *dev,
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
 static int print_allowed_zone(char *buf, int len, int nid,
+			      struct memory_group *group,
 			      unsigned long start_pfn, unsigned long nr_pages,
 			      int online_type, struct zone *default_zone)
 {
 	struct zone *zone;
 
-	zone = zone_for_pfn_range(online_type, nid, start_pfn, nr_pages);
+	zone = zone_for_pfn_range(online_type, nid, group, start_pfn, nr_pages);
 	if (zone == default_zone)
 		return 0;
 
@@ -397,9 +399,10 @@ static ssize_t valid_zones_show(struct device *dev,
 	struct memory_block *mem = to_memory_block(dev);
 	unsigned long start_pfn = section_nr_to_pfn(mem->start_section_nr);
 	unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
+	struct memory_group *group = mem->group;
 	struct zone *default_zone;
+	int nid = mem->nid;
 	int len = 0;
-	int nid;
 
 	/*
 	 * Check the existing zone. Make sure that we do that only on the
@@ -418,14 +421,13 @@ static ssize_t valid_zones_show(struct device *dev,
 		goto out;
 	}
 
-	nid = mem->nid;
-	default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, start_pfn,
-					  nr_pages);
+	default_zone = zone_for_pfn_range(MMOP_ONLINE, nid, group,
+					  start_pfn, nr_pages);
 
 	len += sysfs_emit_at(buf, len, "%s", default_zone->name);
-	len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
 				  MMOP_ONLINE_KERNEL, default_zone);
-	len += print_allowed_zone(buf, len, nid, start_pfn, nr_pages,
+	len += print_allowed_zone(buf, len, nid, group, start_pfn, nr_pages,
 				  MMOP_ONLINE_MOVABLE, default_zone);
 out:
 	len += sysfs_emit_at(buf, len, "\n");