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hugetlb: handle memory hot-plug events

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Register per node hstate attributes only for nodes with memory.  As
suggested by David Rientjes.

With Memory Hotplug, memory can be added to a memoryless node and a node
with memory can become memoryless.  Therefore, add a memory on/off-line
notifier callback to [un]register a node's attributes on transition
to/from memoryless state.

N.B.,  Only tested build, boot, libhugetlbfs regression.
       i.e., no memory hotplug testing.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Eric Whitney <eric.whitney@hp.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Lee Schermerhorn 2009-12-14 17:58:35 -08:00 committed by Linus Torvalds
parent 8fe23e0571
commit 4faf8d950e
2 changed files with 50 additions and 6 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
Documentation/vm/hugetlbpage.txt
View file

@ -231,7 +231,8 @@ resulting effect on persistent huge page allocation is as follows:
Per Node Hugepages Attributes
A subset of the contents of the root huge page control directory in sysfs,
described above, has been replicated under each "node" system device in:
described above, will be replicated under each the system device of each
NUMA node with memory in:
/sys/devices/system/node/node[0-9]*/hugepages/

53
drivers/base/node.c
View file

@ -177,8 +177,8 @@ static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
/*
* hugetlbfs per node attributes registration interface:
* When/if hugetlb[fs] subsystem initializes [sometime after this module],
* it will register its per node attributes for all nodes online at that
* time. It will also call register_hugetlbfs_with_node(), below, to
* it will register its per node attributes for all online nodes with
* memory. It will also call register_hugetlbfs_with_node(), below, to
* register its attribute registration functions with this node driver.
* Once these hooks have been initialized, the node driver will call into
* the hugetlb module to [un]register attributes for hot-plugged nodes.
@ -188,7 +188,8 @@ static node_registration_func_t __hugetlb_unregister_node;
static inline void hugetlb_register_node(struct node *node)
{
if (__hugetlb_register_node)
if (__hugetlb_register_node &&
node_state(node->sysdev.id, N_HIGH_MEMORY))
__hugetlb_register_node(node);
}
@ -233,6 +234,7 @@ int register_node(struct node *node, int num, struct node *parent)
sysdev_create_file(&node->sysdev, &attr_distance);
scan_unevictable_register_node(node);
hugetlb_register_node(node);
}
return error;
@ -254,7 +256,7 @@ void unregister_node(struct node *node)
sysdev_remove_file(&node->sysdev, &attr_distance);
scan_unevictable_unregister_node(node);
hugetlb_unregister_node(node);
hugetlb_unregister_node(node); /* no-op, if memoryless node */
sysdev_unregister(&node->sysdev);
}
@ -384,8 +386,45 @@ static int link_mem_sections(int nid)
}
return err;
}
/*
* Handle per node hstate attribute [un]registration on transistions
* to/from memoryless state.
*/
static int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
struct memory_notify *mnb = arg;
int nid = mnb->status_change_nid;
switch (action) {
case MEM_ONLINE: /* memory successfully brought online */
if (nid != NUMA_NO_NODE)
hugetlb_register_node(&node_devices[nid]);
break;
case MEM_OFFLINE: /* or offline */
if (nid != NUMA_NO_NODE)
hugetlb_unregister_node(&node_devices[nid]);
break;
case MEM_GOING_ONLINE:
case MEM_GOING_OFFLINE:
case MEM_CANCEL_ONLINE:
case MEM_CANCEL_OFFLINE:
default:
break;
}
return NOTIFY_OK;
}
#else
static int link_mem_sections(int nid) { return 0; }
static inline int node_memory_callback(struct notifier_block *self,
unsigned long action, void *arg)
{
return NOTIFY_OK;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
int register_one_node(int nid)
@ -499,13 +538,17 @@ static int node_states_init(void)
return err;
}
#define NODE_CALLBACK_PRI 2 /* lower than SLAB */
static int __init register_node_type(void)
{
int ret;
ret = sysdev_class_register(&node_class);
if (!ret)
if (!ret) {
ret = node_states_init();
hotplug_memory_notifier(node_memory_callback,
NODE_CALLBACK_PRI);
}
/*
* Note: we're not going to unregister the node class if we fail