mm: memory hotplug with an existing resource
Add add_memory_resource() to add memory using an existing "System RAM"
resource. This is useful if the memory region is being located by
finding a free resource slot with allocate_resource().
Xen guests will make use of this in their balloon driver to hotplug
arbitrary amounts of memory in response to toolstack requests.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index aa992e2..0780d11 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1232,23 +1232,21 @@
}
/* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */
-int __ref add_memory(int nid, u64 start, u64 size)
+int __ref add_memory_resource(int nid, struct resource *res)
{
+ u64 start, size;
pg_data_t *pgdat = NULL;
bool new_pgdat;
bool new_node;
- struct resource *res;
int ret;
+ start = res->start;
+ size = resource_size(res);
+
ret = check_hotplug_memory_range(start, size);
if (ret)
return ret;
- res = register_memory_resource(start, size);
- ret = -EEXIST;
- if (!res)
- return ret;
-
{ /* Stupid hack to suppress address-never-null warning */
void *p = NODE_DATA(nid);
new_pgdat = !p;
@@ -1300,13 +1298,28 @@
/* rollback pgdat allocation and others */
if (new_pgdat)
rollback_node_hotadd(nid, pgdat);
- release_memory_resource(res);
memblock_remove(start, size);
out:
mem_hotplug_done();
return ret;
}
+EXPORT_SYMBOL_GPL(add_memory_resource);
+
+int __ref add_memory(int nid, u64 start, u64 size)
+{
+ struct resource *res;
+ int ret;
+
+ res = register_memory_resource(start, size);
+ if (!res)
+ return -EEXIST;
+
+ ret = add_memory_resource(nid, res);
+ if (ret < 0)
+ release_memory_resource(res);
+ return ret;
+}
EXPORT_SYMBOL_GPL(add_memory);
#ifdef CONFIG_MEMORY_HOTREMOVE