Gilles,
You are correct that mpirun is executed on a node other than n15 or n16.
So, your count to 5 makes sense.
It does seem a bit excessive, but it should only occur when there is
problem.
I have no MCA params file nor any MCA-related environment variables.
So, there are no oob_tcp_if_{include,exclude} settings in force.
The patch makes sense to me and appears to fix the problem.
I'll address Ralph's concern about selected-vs-unselected interface
separately.
I still get the SEGV at exit, but that could very well be bit-rot in
mtl/shm.
I will investigate more if/when I have time.
-Paul
On Thu, Dec 11, 2014 at 8:26 PM, Gilles Gouaillardet <
gilles.gouaillar...@iferc.org> wrote:
> Paul,
>
> about the five warnings :
> can you confirm you are running mpirun *not* on n15 nor n16 ?
> if my guess is correct, then you can get up to 5 warnings : mpirun + 2
> orted + 2 mpi tasks
>
> do you have any oob_tcp_if_include or oob_tcp_if_exclude settings in your
> openmpi-mca-params.conf ?
>
> here is attached a patch to fix this issue.
> what we really want is test there is a loopback interface, period.
> the current code (my bad for not having reviewed in a timely manner) seems
> to check
> there is a *selected* loopback interface.
>
> Cheers,
>
> Gilles
>
>
> On 2014/12/12 13:15, Paul Hargrove wrote:
>
> Ralph,
>
> Sorry to be the bearer of more bad news.
> The "good" news is I've seen the new warning regarding the lack of a
> loopback interface.
> The BAD news is that it is occurring on a Linux cluster that I'ver verified
> DOES have 'lo' configured on the front-end and compute nodes (UP and
> RUNNING according to ifconfig).
>
> Though run with "-np 2" the warning appears FIVE times.
> ADDITIONALLY, there is a SEGV at exit!
>
> Unfortunately, despite configuring with --enable-debug, I didn't get line
> numbers from the core (and there was no backtrace printed).
>
> All of this appears below (and no, "-mca mtl psm" is not a typo or a joke).
>
> Let me know what tracing flags to apply to gather the info needed to debug
> this.
>
> -Paul
>
>
> $ mpirun -mca btl sm,self -np 2 -host n15,n16 -mca mtl psm examples/ring_c
> --------------------------------------------------------------------------
> WARNING: No loopback interface was found. This can cause problems
> when we spawn processes as they are likely to be unable to connect
> back to their host daemon. Sadly, it may take awhile for the connect
> attempt to fail, so you may experience a significant hang time.
>
> You may wish to ctrl-c out of your job and activate loopback support
> on at least one interface before trying again.
>
> --------------------------------------------------------------------------
> [... above message FOUR more times ...]
> Process 1 exiting
> Process 0 sending 10 to 1, tag 201 (2 processes in ring)
> Process 0 sent to 1
> Process 0 decremented value: 9
> Process 0 decremented value: 8
> Process 0 decremented value: 7
> Process 0 decremented value: 6
> Process 0 decremented value: 5
> Process 0 decremented value: 4
> Process 0 decremented value: 3
> Process 0 decremented value: 2
> Process 0 decremented value: 1
> Process 0 decremented value: 0
> Process 0 exiting
> --------------------------------------------------------------------------
> mpirun noticed that process rank 0 with PID 0 on node n15 exited on signal
> 11 (Segmentation fault).
> --------------------------------------------------------------------------
>
> $ /sbin/ifconfig lo
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:481228 errors:0 dropped:0 overruns:0 frame:0
> TX packets:481228 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:81039065 (77.2 MiB) TX bytes:81039065 (77.2 MiB)
>
> $ ssh n15 /sbin/ifconfig lo
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:24885 errors:0 dropped:0 overruns:0 frame:0
> TX packets:24885 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:1509940 (1.4 MiB) TX bytes:1509940 (1.4 MiB)
>
> $ ssh n16 /sbin/ifconfig lo
> lo Link encap:Local Loopback
> inet addr:127.0.0.1 Mask:255.0.0.0
> inet6 addr: ::1/128 Scope:Host
> UP LOOPBACK RUNNING MTU:16436 Metric:1
> RX packets:24938 errors:0 dropped:0 overruns:0 frame:0
> TX packets:24938 errors:0 dropped:0 overruns:0 carrier:0
> collisions:0 txqueuelen:0
> RX bytes:1543408 (1.4 MiB) TX bytes:1543408 (1.4 MiB)
>
> $ gdb examples/ring_c core.29728
> [...]
> (gdb) where
> #0 0x0000002a97a19980 in ?? ()
> #1 <signal handler called>
> #2 0x0000003a6d40607c in _Unwind_FindEnclosingFunction () from
> /lib64/libgcc_s.so.1
> #3 0x0000003a6d406b57 in _Unwind_RaiseException () from
> /lib64/libgcc_s.so.1
> #4 0x0000003a6d406c4c in _Unwind_ForcedUnwind () from /lib64/libgcc_s.so.1
> #5 0x0000003a6c30ac50 in __pthread_unwind () from
> /lib64/tls/libpthread.so.0
> #6 0x0000003a6c305202 in sigcancel_handler () from
> /lib64/tls/libpthread.so.0
> #7 <signal handler called>
> #8 0x0000003a6b6bd9a2 in poll () from /lib64/tls/libc.so.6
> #9 0x0000002a978f8f7d in ?? ()
> #10 0x002000010000000e in ?? ()
> #11 0x0000000000000000 in ?? ()
>
>
>
>
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--
Paul H. Hargrove phhargr...@lbl.gov
Computer Languages & Systems Software (CLaSS) Group
Computer Science Department Tel: +1-510-495-2352
Lawrence Berkeley National Laboratory Fax: +1-510-486-6900
