[patch -mm 7/7] x86_64: export physnode mapping to userspace

[David Rientjes <rientjes@google.com>]

Exports the physical NUMA node to fake NUMA node mapping to user-space via
sysfs.  The information is now accessible via the 'physnode' file.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Rohit Seth <rohitseth@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
---
 drivers/base/node.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 001e6f6..548d365 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -136,6 +136,13 @@ static ssize_t node_read_distance(struct sys_device * dev, char * buf)
 }
 static SYSDEV_ATTR(distance, S_IRUGO, node_read_distance, NULL);
 
+#ifdef CONFIG_NUMA_EMU
+static ssize_t node_read_physnode(struct sys_device *dev, char *buf)
+{
+	return sprintf(buf, "%d\n", get_phys_node(dev->id));
+}
+static SYSDEV_ATTR(physnode, S_IRUGO, node_read_physnode, NULL);
+#endif
 
 /*
  * register_node - Setup a driverfs device for a node.
@@ -156,6 +163,9 @@ int register_node(struct node *node, int num, struct node *parent)
 		sysdev_create_file(&node->sysdev, &attr_meminfo);
 		sysdev_create_file(&node->sysdev, &attr_numastat);
 		sysdev_create_file(&node->sysdev, &attr_distance);
+#ifdef CONFIG_NUMA_EMU
+		sysdev_create_file(&node->sysdev, &attr_physnode);
+#endif
 	}
 	return error;
 }
@@ -173,6 +183,9 @@ void unregister_node(struct node *node)
 	sysdev_remove_file(&node->sysdev, &attr_meminfo);
 	sysdev_remove_file(&node->sysdev, &attr_numastat);
 	sysdev_remove_file(&node->sysdev, &attr_distance);
+#ifdef CONFIG_NUMA_EMU
+	sysdev_remove_file(&node->sysdev, &attr_physnode);
+#endif
 
 	sysdev_unregister(&node->sysdev);
 }