diff mbox series

[v4,02/24] bus/vdev: enable one device scan

Message ID 20180626070832.3055-3-qi.z.zhang@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series enable hotplug on multi-process |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation fail Compilation issues

Commit Message

Qi Zhang June 26, 2018, 7:08 a.m. UTC 
  The patch implemented the ops scan_one for vdev bus, it gives two benifits
1. Improve scan efficiency when a device is attached as hotplug, since no
need to pupulate a new device by iterating all devargs in devargs_list.
2. It also avoid sync IPC invoke (which happens in vdev->scan on secondary
process). The benifit is this removes the potential deadlock in the case
when secondary process receive a request from primary process to attach a
new device, since vdev->scan will be invoked on mp thread itself in that
case.

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---

 drivers/bus/vdev/vdev.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

Comments

Remy Horton June 26, 2018, 10:49 a.m. UTC | #1 
On 26/06/2018 08:08, Qi Zhang wrote:
> The patch implemented the ops scan_one for vdev bus, it gives two benifits
> 1. Improve scan efficiency when a device is attached as hotplug, since no
> need to pupulate a new device by iterating all devargs in devargs_list.
> 2. It also avoid sync IPC invoke (which happens in vdev->scan on secondary
> process). The benifit is this removes the potential deadlock in the case
> when secondary process receive a request from primary process to attach a
> new device, since vdev->scan will be invoked on mp thread itself in that
> case.

Slight rewording and spelling corrections within description:

The patch implements the ops scan_one for the vdev bus, which gives two 
benefits:
1. Improves scan efficiency when a device is attached as hotplug, since 
there is no need to populate a new device by iterating all devargs in 
devargs_list
2. It also avoids sync IPC invoke (which happens in vdev->scan on 
secondary process). The benefit is this removes the potential deadlock 
in the case when a secondary process receives a request from primary 
process to attach a new device, since vdev->scan will be invoked on mp 
thread itself in that case.


> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> ---
>
>  drivers/bus/vdev/vdev.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)

Acked-by: Remy Horton <remy.horton@intel.com>
diff mbox series

Patch

diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index 6139dd551..cdbd77df0 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -467,6 +467,35 @@  vdev_scan(void)
 	return 0;
 }
 
+static struct rte_device *vdev_scan_one(struct rte_devargs *devargs)
+{
+	struct rte_vdev_device *dev = NULL;
+
+	dev = calloc(1, sizeof(*dev));
+	if (!dev) {
+		VDEV_LOG(ERR, "failed to allocate memory for new device");
+		return NULL;
+	}
+
+	rte_spinlock_recursive_lock(&vdev_device_list_lock);
+
+	if (find_vdev(devargs->name)) {
+		VDEV_LOG(ERR, "device %s already exist", devargs->name);
+		free(dev);
+		rte_spinlock_recursive_unlock(&vdev_device_list_lock);
+		return NULL;
+	}
+
+	dev->device.devargs = devargs;
+	dev->device.numa_node = SOCKET_ID_ANY;
+	dev->device.name = devargs->name;
+	TAILQ_INSERT_TAIL(&vdev_device_list, dev, next);
+
+	rte_spinlock_recursive_unlock(&vdev_device_list_lock);
+
+	return &dev->device;
+}
+
 static int
 vdev_probe(void)
 {
@@ -531,6 +560,7 @@  vdev_unplug(struct rte_device *dev)
 
 static struct rte_bus rte_vdev_bus = {
 	.scan = vdev_scan,
+	.scan_one = vdev_scan_one,
 	.probe = vdev_probe,
 	.find_device = vdev_find_device,
 	.plug = vdev_plug,