On Tue, Aug 21, 2012 at 7:17 PM, Johnathan Van Why <jrvanwhy [..] ...> wrote:
> On Tue, Aug 21, 2012 at 10:02 AM, Sagar Behere <sagar [dot] behere [..] ...> wrote:
>> On 08/21/2012 06:45 PM, Johnathan Van Why wrote:
>>> (Forwarding to Orocos-users because I accidentally replied directly to
>>> Sagar Behere.)
>>>
>>> ---------- Forwarded message ----------
>>> From: Johnathan Van Why<jrvanwhy [..] ...>
>>> Date: Tue, Aug 21, 2012 at 9:09 AM
>>> Subject: Re: [Orocos-users] Mixing realtime and non-realtime
>>> components in Xenomai deployer?
>>> To: sagar [dot] behere [..] ...
>>>
>>>
>>> On Mon, Aug 20, 2012 at 11:22 PM, Sagar Behere<sagar [dot] behere [..] ...> wrote:
>>>> On 08/21/2012 02:21 AM, Johnathan Van Why wrote:
>>>>> We're trying to port our Orocos-based software from RT_PREEMPT to
>>>>> Xenomai in order to obtain better realtime performance. If we just
>>>>> launch the deployer-xenomai executable, both of our components (we
>>>>> have more, but I'm only trying with 2 right now) run in hard realtime
>>>>> using Xenomai. However, we'd like one to not be in realtime (it will
>>>>> need to access ROS, which is not realtime) and the other to be in
>>>>> realtime.
>>>>>
>>>>> How can we accomplish this?
>>>>
>>>> I think you need to use ORO_SCHED_OTHER. See
>>>>
>>>> http://www.orocos.org/stable/documentation/rtt/v2.x/doc-xml/orocos-compo...
>>>
>>> Sagar,
>>>
>>> We are trying to do that. Here is our deployment script:
>>>
>>> import("atrias_shared")
>>> import("atrias_rt_ops")
>>> import("atrias_noop_conn")
>>>
>>> # Load necessary components.
>>> loadComponent("atrias_rt", "RTOps")
>>> loadComponent("atrias_connector", "NoopConn")
>>>
>>> # Let these see each other.
>>> connectPeers("atrias_connector", "atrias_rt")
>>>
>>> # Make the Noop Connector cyclic
>>> setActivity("atrias_rt", 0, HighestPriority, ORO_SCHED_RT)
>>> setActivity("atrias_connector", 0.001, 0, ORO_SCHED_OTHER)
>>>
>>> # Configure components.
>>> atrias_rt.configure()
>>> atrias_connector.configure()
>>>
>>> # Start components.
>>> atrias_rt.start();
>>> atrias_connector.start();
>>>
>>> Does this not set atrias_noop_conn to use ORO_SCHED_OTHER?
>>
>>
>> That looks about right. Are you doubting that the atrias_connector task
>> context is NOT running as non-realtime?
>>
>> That is similar to how I set the scheduling my components, except that
>> instead of doing it from the deployment script, I do it using code in
>> the configureHook of the component. In fact, the simplest way to set
>> ORO_SCHED_RT is to not specify a priority, whereas specifying one sets
>> the default scheduler to ORO_SCHED_RT.
>
> According to /proc/xenomai/schedclasses/rt/threads , atrias_noop_conn
> is running in Xenomai context w/ a priority of 0.
>
> Perhaps this is just how Orocos on Xenomai works?

Yes. All the threads in one Orocos process are known to Xenomai,
because it's still possible that a RT and a non-RT thread share a
mutex or semaphore. You can't lock a Xenomai mutex/semaphore from a
non-Xenomai thread, so that's why even the not real-time threads need
this registration step. We do set the priority and scheduler to zero
and ORO_SCHED_OTHER such that the right scheduling happens.

Peter

On 08/21/2012 07:17 PM, Johnathan Van Why wrote:
> On Tue, Aug 21, 2012 at 10:02 AM, Sagar Behere<sagar [dot] behere [..] ...> wrote:
>> On 08/21/2012 06:45 PM, Johnathan Van Why wrote:
>>> (Forwarding to Orocos-users because I accidentally replied directly to
>>> Sagar Behere.)
>>>
>>> ---------- Forwarded message ----------
>>> From: Johnathan Van Why<jrvanwhy [..] ...>
>>> Date: Tue, Aug 21, 2012 at 9:09 AM
>>> Subject: Re: [Orocos-users] Mixing realtime and non-realtime
>>> components in Xenomai deployer?
>>> To: sagar [dot] behere [..] ...
>>>
>>>
>>> On Mon, Aug 20, 2012 at 11:22 PM, Sagar Behere<sagar [dot] behere [..] ...> wrote:
>>>> On 08/21/2012 02:21 AM, Johnathan Van Why wrote:
>>>>> We're trying to port our Orocos-based software from RT_PREEMPT to
>>>>> Xenomai in order to obtain better realtime performance. If we just
>>>>> launch the deployer-xenomai executable, both of our components (we
>>>>> have more, but I'm only trying with 2 right now) run in hard realtime
>>>>> using Xenomai. However, we'd like one to not be in realtime (it will
>>>>> need to access ROS, which is not realtime) and the other to be in
>>>>> realtime.
>>>>>
>>>>> How can we accomplish this?
>>>>
>>>> I think you need to use ORO_SCHED_OTHER. See
>>>>
>>>> http://www.orocos.org/stable/documentation/rtt/v2.x/doc-xml/orocos-compo...
>>>
>>> Sagar,
>>>
>>> We are trying to do that. Here is our deployment script:
>>>
>>> import("atrias_shared")
>>> import("atrias_rt_ops")
>>> import("atrias_noop_conn")
>>>
>>> # Load necessary components.
>>> loadComponent("atrias_rt", "RTOps")
>>> loadComponent("atrias_connector", "NoopConn")
>>>
>>> # Let these see each other.
>>> connectPeers("atrias_connector", "atrias_rt")
>>>
>>> # Make the Noop Connector cyclic
>>> setActivity("atrias_rt", 0, HighestPriority, ORO_SCHED_RT)
>>> setActivity("atrias_connector", 0.001, 0, ORO_SCHED_OTHER)
>>>
>>> # Configure components.
>>> atrias_rt.configure()
>>> atrias_connector.configure()
>>>
>>> # Start components.
>>> atrias_rt.start();
>>> atrias_connector.start();
>>>
>>> Does this not set atrias_noop_conn to use ORO_SCHED_OTHER?
>>
>>
>> That looks about right. Are you doubting that the atrias_connector task
>> context is NOT running as non-realtime?
>>
>> That is similar to how I set the scheduling my components, except that
>> instead of doing it from the deployment script, I do it using code in
>> the configureHook of the component. In fact, the simplest way to set
>> ORO_SCHED_RT is to not specify a priority, whereas specifying one sets
>> the default scheduler to ORO_SCHED_RT.
>
> According to /proc/xenomai/schedclasses/rt/threads , atrias_noop_conn
> is running in Xenomai context w/ a priority of 0.
>
> Perhaps this is just how Orocos on Xenomai works?

Ah! I am out of my depth here :(
Perhaps someone else on the list can help out..

Regards,
Sagar