On 9/27/2021 12:31 PM, Michael S. Tsirkin wrote:
On Sun, Sep 26, 2021 at 05:55:17PM +0300, Max Gurtovoy wrote:
Also expose numa_node field as a sysfs attribute. Now virtio device
drivers will be able to allocate memory that is node-local to the
device. This significantly helps performance and it's oftenly used in
other drivers such as NVMe, for example.
Signed-off-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
If you have to respin this, it is better to split this in
two patches, one with the helper one adding a sysfs attribute.
It's not a problem, but it will cause the first commit to include a
method that is not used anywhere.
I'm not sure this is preferred but I can do it.
---
drivers/virtio/virtio.c | 10 ++++++++++
include/linux/virtio.h | 13 +++++++++++++
2 files changed, 23 insertions(+)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 588e02fb91d3..bdbd76c5c58c 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -60,12 +60,22 @@ static ssize_t features_show(struct device *_d,
}
static DEVICE_ATTR_RO(features);
+static ssize_t numa_node_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ struct virtio_device *vdev = dev_to_virtio(_d);
+
+ return sysfs_emit(buf, "%d\n", virtio_dev_to_node(vdev));
+}
+static DEVICE_ATTR_RO(numa_node);
+
static struct attribute *virtio_dev_attrs[] = {
&dev_attr_device.attr,
&dev_attr_vendor.attr,
&dev_attr_status.attr,
&dev_attr_modalias.attr,
&dev_attr_features.attr,
+ &dev_attr_numa_node.attr,
NULL,
};
ATTRIBUTE_GROUPS(virtio_dev);
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 41edbc01ffa4..05b586ac71d1 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -125,6 +125,19 @@ static inline struct virtio_device *dev_to_virtio(struct device *_dev)
return container_of(_dev, struct virtio_device, dev);
}
+/**
+ * virtio_dev_to_node - return the NUMA node for a given virtio device
+ * @vdev: device to get the NUMA node for.
+ */
+static inline int virtio_dev_to_node(struct virtio_device *vdev)
+{
+ struct device *parent = vdev->dev.parent;
+
+ if (!parent)
+ return NUMA_NO_NODE;
+ return dev_to_node(parent);
+}
+
void virtio_add_status(struct virtio_device *dev, unsigned int status);
int register_virtio_device(struct virtio_device *dev);
void unregister_virtio_device(struct virtio_device *dev);
--
2.18.1
