mm, memory_hotplug: drop arch_free_nodedata

Prior to "mm: handle uninitialized numa nodes gracefully" memory hotplug
used to allocate pgdat when memory has been added to a node
(hotadd_init_pgdat) arch_free_nodedata has been only used in the failure
path because once the pgdat is exported (to be visible by NODA_DATA(nid))
it cannot really be freed because there is no synchronization available
for that.

pgdat is allocated for each possible nodes now so the memory hotplug
doesn't need to do the ever use arch_free_nodedata so drop it.

This patch doesn't introduce any functional change.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Acked-by: Rafael Aquini <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Acked-by: Mike Rapoport <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: Alexey Makhalov <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Dennis Zhou <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Nico Pache <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

3 files changed, 0 insertions, 18 deletions

diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c
index dd0cf4834eaa..73d0db36edb6 100644
--- a/arch/ia64/mm/discontig.c
+++ b/arch/ia64/mm/discontig.c
@@ -615,11 +615,6 @@ pg_data_t * __init arch_alloc_nodedata(int nid)
 	return memblock_alloc(size, SMP_CACHE_BYTES);
 }
 
-void arch_free_nodedata(pg_data_t *pgdat)
-{
-	kfree(pgdat);
-}
-
 void arch_refresh_nodedata(int update_node, pg_data_t *update_pgdat)
 {
 	pgdat_list[update_node] = update_pgdat;
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index cdd66bfdf855..60f09d3ebb3d 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -24,17 +24,14 @@ struct vmem_altmap;
  * node_data[nid] = kzalloc() works well. But it depends on the architecture.
  *
  * In general, generic_alloc_nodedata() is used.
- * Now, arch_free_nodedata() is just defined for error path of node_hot_add.
  *
  */
 extern pg_data_t *arch_alloc_nodedata(int nid);
-extern void arch_free_nodedata(pg_data_t *pgdat);
 extern void arch_refresh_nodedata(int nid, pg_data_t *pgdat);
 
 #else /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
 
 #define arch_alloc_nodedata(nid)	generic_alloc_nodedata(nid)
-#define arch_free_nodedata(pgdat)	generic_free_nodedata(pgdat)
 
 #ifdef CONFIG_NUMA
 /*
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 11f39d0e76ec..55c3e5309088 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1217,16 +1217,6 @@ static pg_data_t __ref *hotadd_init_pgdat(int nid)
 	return pgdat;
 }
 
-static void rollback_node_hotadd(int nid)
-{
-	pg_data_t *pgdat = NODE_DATA(nid);
-
-	arch_refresh_nodedata(nid, NULL);
-	free_percpu(pgdat->per_cpu_nodestats);
-	arch_free_nodedata(pgdat);
-}
-
-
 /*
  * __try_online_node - online a node if offlined
  * @nid: the node ID