On Feb 18, 2014, at 13:16 , Jeff Squyres (jsquyres) <jsquy...@cisco.com> wrote:
> Ok, fair enough. My goal was not to spin up another progress thread in my
> BTL, but I can certainly do so (to meet the 1.7.5 timeframe).
>
> For the longer term (i.e., 1.9), should we add a little opal infrastructure
> that contains an event base that is run in its own progress thread? This
> would allow the MPI layer to consolidate into one progress thread (for things
> that are event based, at least). I don’t believe much work would be needed
> here.
+1. All frameworks/component with a need for event triggering without other
constraints must use it. In other terms the proposed infrastructure might not
be the most effective for high density fd listeners such as the TCP BTL.
> For example, the openib BTL could use this async-thread event-driven
> infrastructure, too (vs. spinning up 2 progress threads of its own).
>
> FWIW: the usNIC BTL events I need will be driven by timers and fd's, so it
> fits into the libevent model just fine (although I have some thoughts of
> possibly adapting this functionality to run in the orted when possible in the
> 1.9 timeframe, but I haven't thought that through yet... 1.7.5 first!).
Btw, now that we’re talking about this I wonder how do we deal with signals in
a non-ORTE environment. Who is registering the signal callbacks, such as USR1?
George.
>
>
>
> On Feb 18, 2014, at 5:21 AM, George Bosilca <bosi...@icl.utk.edu> wrote:
>
>> I concur with Brian, you should not expect the runtime to provide a default
>> event base, especially if you want some level of quality-of-service out of
>> it. Moreover, with the soon-to-happen move of the BTLs down in OPAL this
>> approach will definitively not be suitable.
>>
>> George.
>>
>>
>> On Feb 18, 2014, at 07:03 , Brian Barrett <br...@bbarrett.org> wrote:
>>
>>> And what will you do for RTE components that aren't ORTE? This really
>>> isn't a feature of a run-time, so it doesn't seem like it should be part of
>>> the RTE interface...
>>>
>>> Brian
>>>
>>> On Feb 17, 2014, at 3:03 PM, Jeff Squyres (jsquyres) <jsquy...@cisco.com>
>>> wrote:
>>>
>>>> WHAT: New OMPI_RTE_EVENT_BASE define
>>>>
>>>> WHY: The usnic BTL needs to run some events asynchronously; the ORTE event
>>>> base already exists and is running asynchronously in MPI processes
>>>>
>>>> WHERE: in ompi/mca/rte/rte.h and rte_orte.h
>>>>
>>>> TIMEOUT: COB Friday, 21 Feb 2014
>>>>
>>>> MORE DETAIL:
>>>>
>>>> The WHY line described it pretty well: we want to run some things
>>>> asynchronously in the usnic BTL and we don't really want to re-invent the
>>>> wheel (or add yet another thread in each MPI process). The ORTE event
>>>> base is already there, there's already a thread servicing it, and Ralph
>>>> tells me that it is safe to add our own events on to it.
>>>>
>>>> The patch below adds the new OMPI_RTE_EVENT_BASE #define.
>>>>
>>>>
>>>> diff --git a/ompi/mca/rte/orte/rte_orte.h b/ompi/mca/rte/orte/rte_orte.h
>>>> index 3c88c6d..3ceadb8 100644
>>>> --- a/ompi/mca/rte/orte/rte_orte.h
>>>> +++ b/ompi/mca/rte/orte/rte_orte.h
>>>> @@ -142,6 +142,9 @@ typedef struct {
>>>> } ompi_orte_tracker_t;
>>>> OBJ_CLASS_DECLARATION(ompi_orte_tracker_t);
>>>>
>>>> +/* define the event base that the RTE exports */
>>>> +#define OMPI_RTE_EVENT_BASE orte_event_base
>>>> +
>>>> END_C_DECLS
>>>>
>>>> #endif /* MCA_OMPI_RTE_ORTE_H */
>>>> diff --git a/ompi/mca/rte/rte.h b/ompi/mca/rte/rte.h
>>>> index 69ad488..de10dff 100644
>>>> --- a/ompi/mca/rte/rte.h
>>>> +++ b/ompi/mca/rte/rte.h
>>>> @@ -150,7 +150,9 @@
>>>> * a. OMPI_DB_HOSTNAME
>>>> * b. OMPI_DB_LOCALITY
>>>> *
>>>> - * (g) Communication support
>>>> + * (g) Asynchronous / event support
>>>> + * 1. OMPI_RTE_EVENT_BASE - the libevent base that executes in a
>>>> + * separate thread
>>>> *
>>>> */
>>>>
>>>> @@ -162,6 +164,7 @@
>>>> #include "opal/dss/dss_types.h"
>>>> #include "opal/mca/mca.h"
>>>> #include "opal/mca/base/base.h"
>>>> +#include "opal/mca/event/event.h"
>>>>
>>>> BEGIN_C_DECLS
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>>
>>>
>>> --
>>> Brian Barrett
>>>
>>> There is an art . . . to flying. The knack lies in learning how to
>>> throw yourself at the ground and miss.
>>> Douglas Adams, 'The Hitchhikers Guide to the Galaxy'
>>>
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>>
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>
>
> --
> Jeff Squyres
> jsquy...@cisco.com
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