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authorDan Williams <dan.j.williams@intel.com>2019-02-20 11:39:36 -0800
committerDan Williams <dan.j.williams@intel.com>2019-02-20 11:39:36 -0800
commit21c75763a3ae18679e5c4e2260aa9379b073566b (patch)
treee9a1881968a95aac7c70bcc1b6a3b448b46254e2
parent664525b2d84abca1074c9546654ae9689de8a818 (diff)
downloadlinux-0-day-21c75763a3ae18679e5c4e2260aa9379b073566b.tar.gz
linux-0-day-21c75763a3ae18679e5c4e2260aa9379b073566b.tar.xz
device-dax: Add a 'target_node' attribute
The target-node attribute is the Linux numa-node that a device-dax instance may create when it is online. Prior to being online the device's 'numa_node' property reflects the closest online cpu node which is the typical expectation of a device 'numa_node'. Once it is online it becomes its own distinct numa node, i.e. 'target_node'. Export the 'target_node' property to give userspace tooling the ability to predict the effective numa-node from a device-dax instance configured to provide 'System RAM' capacity. Cc: Vishal Verma <vishal.l.verma@intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/dax/bus.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index a410154d75fb9..28c3324271acd 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -279,13 +279,41 @@ static ssize_t size_show(struct device *dev,
}
static DEVICE_ATTR_RO(size);
+static int dev_dax_target_node(struct dev_dax *dev_dax)
+{
+ struct dax_region *dax_region = dev_dax->region;
+
+ return dax_region->target_node;
+}
+
+static ssize_t target_node_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dev_dax *dev_dax = to_dev_dax(dev);
+
+ return sprintf(buf, "%d\n", dev_dax_target_node(dev_dax));
+}
+static DEVICE_ATTR_RO(target_node);
+
+static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, struct device, kobj);
+ struct dev_dax *dev_dax = to_dev_dax(dev);
+
+ if (a == &dev_attr_target_node.attr && dev_dax_target_node(dev_dax) < 0)
+ return 0;
+ return a->mode;
+}
+
static struct attribute *dev_dax_attributes[] = {
&dev_attr_size.attr,
+ &dev_attr_target_node.attr,
NULL,
};
static const struct attribute_group dev_dax_attribute_group = {
.attrs = dev_dax_attributes,
+ .is_visible = dev_dax_visible,
};
static const struct attribute_group *dax_attribute_groups[] = {