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authorDavid Vrabel <david.vrabel@citrix.com>2015-06-25 16:35:49 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2015-10-23 14:19:58 +0100
commit62cedb9f135794ec26a93ae29e5f0231ab263c84 (patch)
tree391e9f85e552feee52c6527daf7c95548572b6d0
parent7379047d5585187d1288486d4627873170d0005a (diff)
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>
-rw-r--r--include/linux/memory_hotplug.h2
-rw-r--r--mm/memory_hotplug.c29
2 files changed, 23 insertions, 8 deletions
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 8f60e899b33c..2ea574ff9714 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -11,6 +11,7 @@ struct zone;
struct pglist_data;
struct mem_section;
struct memory_block;
+struct resource;
#ifdef CONFIG_MEMORY_HOTPLUG
@@ -266,6 +267,7 @@ static inline void remove_memory(int nid, u64 start, u64 size) {}
extern int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
void *arg, int (*func)(struct memory_block *, void *));
extern int add_memory(int nid, u64 start, u64 size);
+extern int add_memory_resource(int nid, struct resource *resource);
extern int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
bool for_device);
extern int arch_add_memory(int nid, u64 start, u64 size, bool for_device);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index aa992e2df58a..0780d118d26e 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1232,23 +1232,21 @@ int zone_for_memory(int nid, u64 start, u64 size, int zone_default,
}
/* 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 @@ error:
/* 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