From: Fan Du <fan.du@xxxxxxxxx>
User space migration daemon could check
/sys/bus/node/devices/nodeX/type for node type.
Software can interrogate node type for node memory type and distance
to get desirable target node in migration.
grep -r . /sys/devices/system/node/*/type
/sys/devices/system/node/node0/type:dram
/sys/devices/system/node/node1/type:dram
/sys/devices/system/node/node2/type:pmem
/sys/devices/system/node/node3/type:pmem
Along with next patch which export `peer_node`, migration daemon
could easily find the memory type of current node, and the target
node in case of migration.
grep -r . /sys/devices/system/node/*/peer_node
/sys/devices/system/node/node0/peer_node:2
/sys/devices/system/node/node1/peer_node:3
/sys/devices/system/node/node2/peer_node:0
/sys/devices/system/node/node3/peer_node:1
Signed-off-by: Fan Du <fan.du@xxxxxxxxx>
Signed-off-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
---
drivers/base/node.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- linux.orig/drivers/base/node.c 2018-12-23 19:39:04.763414931 +0800
+++ linux/drivers/base/node.c 2018-12-23 19:39:04.763414931 +0800
@@ -233,6 +233,15 @@ static ssize_t node_read_distance(struct
}
static DEVICE_ATTR(distance, S_IRUGO, node_read_distance, NULL);
+static ssize_t type_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int nid = dev->id;
+
+ return sprintf(buf, is_node_pmem(nid) ? "pmem\n" : "dram\n");
+}
+static DEVICE_ATTR(type, S_IRUGO, type_show, NULL);
+
static struct attribute *node_dev_attrs[] = {
&dev_attr_cpumap.attr,
&dev_attr_cpulist.attr,
@@ -240,6 +249,7 @@ static struct attribute *node_dev_attrs[
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
+ &dev_attr_type.attr,
NULL
};
ATTRIBUTE_GROUPS(node_dev);
