On 20-Apr-18 3:28 PM, Tan, Jianfeng wrote:
On 4/20/2018 4:41 PM, Burakov, Anatoly wrote:
On 19-Apr-18 5:50 PM, Jianfeng Tan wrote:
To scan the vdevs in primary, we send request to primary process
to obtain the names for vdevs.
Only the name is shared from the primary. In probe(), the device
driver is supposed to locate (or request more) the detail
information from the primary.
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
Reviewed-by: Qi Zhang <qi.z.zh...@intel.com>
---
<...>
+static int
+vdev_action(const struct rte_mp_msg *mp_msg, const void *peer)
+{
+ struct rte_vdev_device *dev;
+ struct rte_mp_msg mp_resp;
+ struct vdev_param *ou = (struct vdev_param *)&mp_resp.param;
+ const struct vdev_param *in = (const struct vdev_param
*)mp_msg->param;
+ const char *devname;
+ int num;
+
+ strcpy(mp_resp.name, "vdev");
+ mp_resp.len_param = sizeof(*ou);
+ mp_resp.num_fds = 0;
+
+ switch (in->type) {
+ case VDEV_SCAN_REQ:
+ ou->type = VDEV_SCAN_ONE;
+ ou->num = 1;
+ num = 0;
+
+ rte_spinlock_lock(&vdev_device_list_lock);
+ TAILQ_FOREACH(dev, &vdev_device_list, next) {
+ devname = rte_vdev_device_name(dev);
+ if (strlen(devname) == 0)
+ VDEV_LOG(INFO, "vdev with no name is not sent");
+ VDEV_LOG(INFO, "send vdev, %s", devname);
+ strncpy(ou->name, devname, RTE_DEV_NAME_MAX_LEN);
Probably better use strlcpy as it always null-terminates.
Yep.
+ if (rte_mp_sendmsg(&mp_resp) < 0)
+ VDEV_LOG(ERR, "send vdev, %s, failed, %s",
+ devname, strerror(rte_errno));
+ num++;
Some comments on what is going on here (why are we sending messages in
response? why multiple? who will receive these messages?) would be nice.
Yep, will explain that below.
I have a sneaking suspicion that you could've packed the response into
one single message, but i'm not completely sure what is going on here,
so maybe what you have here makes sense...
What's happening here is that:
a. Secondary process sends a sync request to ask for vdev in primary.
b. Primary process receives the request, and send vdevs one by one.
c. Primary process sends back reply, which indicates how many vdevs are
sent.
The reason we don't pack all vdevs in the reply message is that, the
message length is RTE_MP_MAX_PARAM_LEN (256) in length. It's possible
that we cannot pack all vdevs in the single reply message.
OK. How does secondary know which vdevs are new and which aren't? Does
it even matter how many vdevs primary has sent? Correct me if i'm wrong,
but it seems that you're only using sync request as kind of
synchronization mechanism, and are not actually expecting any useful
data in the reply. Which is OK, but in that case just don't bother
sending any data in the reply in the first place :)
--
Thanks,
Anatoly
