We certainly want to give better error messages where possible. I've created a ticket for it: https://trac.mpich.org/projects/mpich/ticket/1872 -- Pavan On 05/29/2013 04:37 PM, Edscott Wilson wrote:

2013/5/29 Jeff Hammond <[email protected] <mailto:[email protected]>>

> > > Wouldn't a message such as "`pwd` directory does not exist on node velascoj" > be more illustrative?

Yes. However, the set of improper uses of MPI that could generate helpful error messages is uncountable. Do you not think it is a good use of finite developer effort to implement an infinitesimal fraction of such warnings? There has to be a minimum requirement placed upon the user. I personally think that it should include running in a directory that actually exists.

Certainly! But then again, some developer must have thought it a good idea, since under different circumstances, I get:

/bin/bash -c mpiexec -n 1 -hosts tauro,velascoj gmandel [proxy:0:0@tauro] launch_procs (./pm/pmiserv/pmip_cb.c:648): unable to change wdir to /tmp/edscott/mnt/tauro-home/GIT/gmandel (No such file or directory) [proxy:0:0@tauro] HYD_pmcd_pmip_control_cmd_cb (./pm/pmiserv/pmip_cb.c:893): launch_procs returned error [proxy:0:0@tauro] HYDT_dmxu_poll_wait_for_event (./tools/demux/demux_poll.c:77): callback returned error status [proxy:0:0@tauro] main (./pm/pmiserv/pmip.c:206): demux engine error waiting for event [mpiexec@velascoj] control_cb (./pm/pmiserv/pmiserv_cb.c:202): assert (!closed) failed [mpiexec@velascoj] HYDT_dmxu_poll_wait_for_event (./tools/demux/demux_poll.c:77): callback returned error status [mpiexec@velascoj] HYD_pmci_wait_for_completion (./pm/pmiserv/pmiserv_pmci.c:197): error waiting for event [mpiexec@velascoj] main (./ui/mpich/mpiexec.c:331): process manager error waiting for completion Which is inconsistent with the previous behavior. Anyways, its no big deal.

BTW, would you happen to know why a process which is started with MPI_Comm_spawn will go into what seems like an active wait after MPI_Comm_disconnect and MPI_Finalize has been called? These spawned processed will hog up CPU until the parent process exits. Curious enough, this behavior is not mirrored in openmpi.

Edscott

------------------------------- Dr. Edscott Wilson Garcia Applied Mathematics and Computing Mexican Petroleum Institute

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