If it is the application, then there is probably a barrier in the app_coord_init() to make sure all the applications are up and running. After this point then the global coordinator knows that the application can be checkpointed.
I don't think orte-checkpoint should be calling a barrier - from what I recall. On Mon, Jan 20, 2014 at 4:46 PM, Ralph Castain <r...@open-mpi.org> wrote: > Is it orte-checkpoint that is hanging, or the app you are trying to > checkpoint? > > > On Jan 20, 2014, at 2:10 PM, Adrian Reber <adr...@lisas.de> wrote: > > Thanks for your help. I tried initializing the barrier correctly (see > attached patch) but now, instead of crashing, it just hangs on the > barrier while running orte-checkpoint > > [dcbz:20150] [[41665,0],0] grpcomm:bad entering barrier > [dcbz:20150] [[41665,0],0] ACTIVATING GRCPCOMM OP 0 at > ../../../../../orte/mca/grpcomm/bad/grpcomm_bad_module.c:206 > > #0 0x00007ffff69befa0 in __nanosleep_nocancel () at > ../sysdeps/unix/syscall-template.S:81 > #1 0x00007ffff7b456ba in app_coord_init () at > ../../../../../orte/mca/snapc/full/snapc_full_app.c:207 > #2 0x00007ffff7b3a582 in orte_snapc_full_module_init (seed=false, > app=true) at ../../../../../orte/mca/snapc/full/snapc_full_module.c:207 > > it hangs looping at ORTE_WAIT_FOR_COMPLETION(coll->active); > > I do not understand on what the barrier here is actually waiting for. Where > do I need to look to find the place the barrier is waiting for? > > I also tried initializing the collective id's in > orte/mca/plm/base/plm_base_launch_support.c but that code is never > used running the orte-checkpoint tool > > Adrian > > On Sat, Jan 11, 2014 at 11:46:42AM -0800, Ralph Castain wrote: > > I took a look at this, and I'm afraid you have some work to do in the > orte/mca/snapc code base: > > 1. you must use dynamically allocated buffers for rml.send_buffer_nb. See > r30261 for an example of the changes that need to be made - I did some, but > can't swear to catching them all. It was enough to at least get a proc past > the initial snapc registration > > 2. you are reusing collective id's to execute several orte_grpcomm.barrier > calls - those ids are used elsewhere during MPI_Init. This is not allowed - > a collective id can only be used *once*. What you need to do is go into > orte/mca/plm/base/plm_base_launch_support.c and (when cr is configured) add > cr-specific collective id's for this purpose. I don't know how many places > in the cr code create their own barriers, but they each need a collective > id. > > If you prefer and have the time, you are welcome to extend the collective > code to allow id reuse. This would require that each daemon and app "reset" > the collective fields when a collective is declared complete. It isn't that > hard to do - just never had a reason to do it. I can take a shot at it when > time permits (may have some time this weekend) > > 3. when you post the non-blocking recv in the snapc/full code, it looks to > me like you need to block until you get the answer. I don't know where in > the code flow this is occurring - if you are not in an event, then it is > okay to block using ORTE_WAIT_FOR_COMPLETION. Look in > orte/mca/routed/base/routed_base_fns.c starting at line 252 for an example. > > HTH > Ralph > > On Jan 10, 2014, at 12:55 PM, Ralph Castain <r...@open-mpi.org> wrote: > > > On Jan 10, 2014, at 12:45 PM, Adrian Reber <adr...@lisas.de> wrote: > > On Fri, Jan 10, 2014 at 09:48:14AM -0800, Ralph Castain wrote: > > > On Jan 10, 2014, at 8:02 AM, Adrian Reber <adr...@lisas.de> wrote: > > I am currently trying to understand how callbacks are working. Right now > I am looking at orte/mca/rml/base/rml_base_receive.c > orte_rml_base_comm_start() which does > > orte_rml.recv_buffer_nb(ORTE_NAME_WILDCARD, > ORTE_RML_TAG_RML_INFO_UPDATE, > ORTE_RML_PERSISTENT, > orte_rml_base_recv, > NULL); > > As far as I understand it orte_rml_base_recv() is the callback function. > At which point should this function run? When the data is actually > received? > > > Not precisely. When data is received by the OOB, it pushes the data into > an event. When that event gets serviced, it calls the orte_rml_base_receive > function which processes the data to find the matching tag, and then uses > that to execute the callback to the user code. > > > The same for send_buffer_nb() functions. I do not see the callback > functions actually running. How can I verify that the callback functions > are running. Especially for the send case it sounds pretty obvious how > it should work but I never see the callback function running. At least > in my setup. > > > The data is not immediately sent. It gets pushed into an event. When that > event gets serviced, it calls the orte_oob_base_send function which then > passes the data to each active OOB component until one of them says it can > send it. The data is then pushed into another event to get it into the > event base for that component's active module - when that event gets > serviced, the data is sent. Once the data is sent, an event is created > that, when serviced, executes the callback to the user code. > > If you aren't seeing callbacks, the most likely cause is that the orte > progress thread isn't running. Without it, none of this will work. > > > Thanks. Running configure without '--with-ft=cr' I can run a program and > use orte-top. In orterun I can see that the callback is running and > orte-top displays the retrieved information. I can also see in orte-top > that the callbacks are working. > > > Actually, I'm rather impressed - I hadn't tested orte-top and didn't > honestly know if it would work any more! Glad to hear it does :-) > > Doing the same with '--with-ft=cr' > enabled orte-top crashes as well as orte-checkpoint and both (-top and > -checkpoint) seem to no longer have working callbacks and that is why > they are probably crashing. So some code which is enabled by '--with-ft=cr' > seems to break callbacks in orte-top as well as in orte-checkpoint. > orterun handles callbacks no matter if configured with or without > '--with-ft=cr'. > > > I can take a look this weekend - probably something silly > > > Adrian > > <grpcomm.txt>_______________________________________________ > > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel > -- Joshua Hursey Assistant Professor of Computer Science University of Wisconsin-La Crosse http://cs.uwlax.edu/~jjhursey
