[PATCH v2 3/3] libnvdimm: Add sysfs numa_node to NVDIMM devices

Toshi Kani
2015-06-09T23:10:40Z

Add support of sysfs 'numa_node' to I/O-related NVDIMM devices
under /sys/bus/nd/devices, regionN, namespaceN.0, and bttN.
When bttN is not set up, its numa_node returns -1 (NUMA_NO_NODE).

Here is an example of numa_node values on a 2-socket system with
a single NVDIMM range on each socket.
/sys/bus/nd/devices
|-- btt0/numa_node:-1
|-- btt1/numa_node:0
|-- namespace0.0/numa_node:0
|-- namespace1.0/numa_node:1
|-- region0/numa_node:0
|-- region1/numa_node:1

These numa_node files are then linked under the block class of
their device names.
/sys/class/block/pmem0/device/numa_node:0
/sys/class/block/pmem0s/device/numa_node:0
/sys/class/block/pmem1/device/numa_node:1

This enables numactl(8) to accept 'block:' and 'file:' paths of
pmem and btt devices as shown in the examples below.
numactl --preferred block:pmem0 --show
numactl --preferred file:/dev/pmem0s --show

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
---
drivers/acpi/nfit.c | 1 +
drivers/nvdimm/btt_devs.c | 1 +
drivers/nvdimm/bus.c | 30 ++++++++++++++++++++++++++++++
drivers/nvdimm/namespace_devs.c | 1 +
include/linux/libnvdimm.h | 1 +
5 files changed, 34 insertions(+)

diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 69dc6e0..ebcaf2a 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -789,6 +789,7 @@ static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
&nd_region_attribute_group,
&nd_mapping_attribute_group,
&nd_device_attribute_group,
+ &nd_numa_attribute_group,
&acpi_nfit_region_attribute_group,
NULL,
};
diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index 740b560..4a053e9 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -295,6 +295,7 @@ static struct attribute_group nd_btt_attribute_group = {
static const struct attribute_group *nd_btt_attribute_groups[] = {
&nd_btt_attribute_group,
&nd_device_attribute_group,
+ &nd_numa_attribute_group,
NULL,
};

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index d8a1794..20ffacc 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -353,6 +353,36 @@ struct attribute_group nd_device_attribute_group = {
};
EXPORT_SYMBOL_GPL(nd_device_attribute_group);

+static ssize_t numa_node_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%d\n", dev_to_node(dev));
+}
+static DEVICE_ATTR_RO(numa_node);
+
+static struct attribute *nd_numa_attributes[] = {
+ &dev_attr_numa_node.attr,
+ NULL,
+};
+
+static umode_t nd_numa_attr_visible(struct kobject *kobj, struct attribute *a,
+ int n)
+{
+ if (!IS_ENABLED(CONFIG_NUMA))
+ return 0;
+
+ return a->mode;
+}
+
+/**
+ * nd_numa_attribute_group - NUMA attributes for all devices on an nd bus
+ */
+struct attribute_group nd_numa_attribute_group = {
+ .attrs = nd_numa_attributes,
+ .is_visible = nd_numa_attr_visible,
+};
+EXPORT_SYMBOL_GPL(nd_numa_attribute_group);
+
int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
{
dev_t devt = MKDEV(nvdimm_bus_major, nvdimm_bus->id);
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index e89b019..26f877f 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1123,6 +1123,7 @@ static struct attribute_group nd_namespace_attribute_group = {
static const struct attribute_group *nd_namespace_attribute_groups[] = {
&nd_device_attribute_group,
&nd_namespace_attribute_group,
+ &nd_numa_attribute_group,
NULL,
};

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 5d0c75a..a85566b 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -35,6 +35,7 @@ enum {
extern struct attribute_group nvdimm_bus_attribute_group;
extern struct attribute_group nvdimm_attribute_group;
extern struct attribute_group nd_device_attribute_group;
+extern struct attribute_group nd_numa_attribute_group;
extern struct attribute_group nd_region_attribute_group;
extern struct attribute_group nd_mapping_attribute_group;