No need - looks like I just need to fail faster and add this possibility to the error message.
Thanks! > On Nov 25, 2014, at 4:50 PM, Paul Hargrove <phhargr...@lbl.gov> wrote: > > Ralph, > > I had a look at the problem via "mpirun -np 1 strace -o trace -ff ./hello" > I find that there is an attempt (by a secondary thread) to establish a TCP > socket from the rank process to the eth0 address of localhost (I am guessing > to reach the orted/mpirun). > However, when the "lo" interface is down, the Linux kernel apparently cannot > establish that socket. > > In fact, if I am sufficiently patient, it turns out the "hang" is bounded, > and eventually one sees: > > phargrov@blcr-armv7:~$ time mpirun -np 1 ./a.out > ------------------------------------------------------------ > A process or daemon was unable to complete a TCP connection > to another process: > Local host: blcr-armv7 > Remote host: 10.0.2.15 > This is usually caused by a firewall on the remote host. Please > check that any firewall (e.g., iptables) has been disabled and > try again. > ------------------------------------------------------------ > > real 2m8.151s > user 0m5.360s > sys 0m57.430s > > > Where blcr-armv7 and 10.0.2.15 are *both* the local (only) host. > > There is no firewall, but in case you doubt me on that, here is a > demonstration using ping to show that 10.0.2.15 is only reachable when the > loopback interface is enabled: > > phargrov@blcr-armv7:~$ sudo ifconfig lo up > phargrov@blcr-armv7:~$ ping -q -c2 10.0.2.15 > PING 10.0.2.15 (10.0.2.15) 56(84) bytes of data. > > --- 10.0.2.15 ping statistics --- > 2 packets transmitted, 2 received, 0% packet loss, time 1002ms > rtt min/avg/max/mdev = 0.527/0.534/0.542/0.024 ms > > > phargrov@blcr-armv7:~$ sudo ifconfig lo down > phargrov@blcr-armv7:~$ ping -q -c2 10.0.2.15 > PING 10.0.2.15 (10.0.2.15) 56(84) bytes of data. > > --- 10.0.2.15 ping statistics --- > 2 packets transmitted, 0 received, 100% packet loss, time 1006ms > > > So, there is no "hang" -- just a 2 minute pause before the error message is > generated. > However, it may still be possible to present a better/earlier error message > when there is no loopback interface (and at least one rank process is to be > launched locally). > > > -Paul > > On Tue, Nov 25, 2014 at 4:19 PM, Ralph Castain <r...@open-mpi.org > <mailto:r...@open-mpi.org>> wrote: > I’ll have to look - there isn’t supposed to be such a requirement, and I > certainly haven’t seen it before. > > >> On Nov 25, 2014, at 3:26 PM, Paul Hargrove <phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov>> wrote: >> >> Allan, >> >> I am glad things are working for you now. >> I can confirm (on a QEMU-emulated Versatile Express A9 board running Ubuntu >> 14.04) that disabling the "lo" interface reproduces the problem. >> I imagine this is true on other architectures, though I did not attempt to >> verify. >> >> Ralph, >> >> If oob:tcp really does need the loopback interface, shouldn't its lack be >> something that could/should be detected and reported instead of hanging as >> Allan saw? >> >> FWIW, neither of the following resolved the problem: >> -mca oob_tcp_if_exclude lo >> -mca oob_tcp_if_include eth0 >> >> >> -Paul >> >> On Tue, Nov 25, 2014 at 2:58 PM, Allan Wu <al...@cs.ucla.edu >> <mailto:al...@cs.ucla.edu>> wrote: >> I think I have found the problem. After inspecting the output with "-mca >> state_base_verbose 10 -mca odls_base_verbose 10 -mca oob_base_verbose 100" >> on both the old system and the new system, I noticed there is one line that >> is different: on the old system where it works correctly, there is a line >> that says: "oob:tcp:init rejecting loopback interface lo", while on the new >> system there is no such line. Both system proceed to open interface eth0 >> afterwards. Then I checked the new system, and found out that somehow the >> loopback interface is not up by default. After I opened the lo interface, >> the mpirun executes normally. >> >> Does it means that OpenMPI will use lo for some initial setup? Since the >> actual socket was created on eth0 I did not think of checking the lo >> interface. Anyway, thanks everyone for all of your kind help. Let me know if >> you want me to provide any more information for future references. >> >> Regards, >> Allan >> >> -- >> Di Wu (Allan) >> PhD student, VAST Laboratory <http://vast.cs.ucla.edu/>, >> Department of Computer Science, UC Los Angeles >> Email: al...@cs.ucla.edu <mailto:al...@cs.ucla.edu> >> >> On Tue, Nov 25, 2014 at 11:55 AM, Allan Wu <al...@cs.ucla.edu >> <mailto:al...@cs.ucla.edu>> wrote: >> Thanks Ralph! >> >> I did not compile my openmpi with --enable-debug, and I am compiling it now. >> But your suggested command already provided some output, which I attached >> with this email. >> >> It seems the process was stuck on the line: >> "[fpga2:00962] [[44848,1],0] waiting for connect completion to [[44848,0],0] >> - activating send event" >> >> Then it got stuck and I CTRL+C'ed it. Previous to that line, it said >> something about 'orte_tcp_peer_try_connect: attempting to connect to proc >> [[44848,0],0] via interface eth0'. >> >> Regards, >> Di >> >> On Tue, Nov 25, 2014 at 2:25 PM, Ralph Castain <r...@open-mpi.org >> <mailto:r...@open-mpi.org>> wrote: >> This is all running on a single node, correct? If so, did you configure OMPI >> with —enable-debug? >> If you can do that, or already have, then let’s add the following to the >> mpirun cmd line: >> >> -mca state_base_verbose 10 -mca odls_base_verbose 10 -mca oob_base_verbose >> 10 >> >> You’ll get a bunch of output, but hopefully it will tell us where mpirun >> is encountering a problem. >> Ralph >> >> On Tue, Nov 25, 2014 at 11:20 AM, Paul Hargrove <phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov>> wrote: >> Allan, >> >> If you send me the .config from your build of the kernel I can compare it >> against, for instance, my .config for a Raspberry Pi. >> There will certainly be many differences, but I am hoping my own experience >> configuring linux kernels will help me filter the "noise" from any >> differences that might be significant. >> >> -Paul >> >> On Tue, Nov 25, 2014 at 11:11 AM, Allan Wu <al...@cs.ucla.edu >> <mailto:al...@cs.ucla.edu>> wrote: >> Thanks Paul! Unfortunately '/boot' is not available in my embedded linux, >> and I do not have the configuration file for the old kernel since it is >> provided as is. However, I have the new kernel configuration since I >> compiled it myself. Would it be helpful if I provide you the .config file >> when I compile the kernel? It maybe quite painful to look through that file >> though. Is there any other way that I can obtain the configuration? >> >> I checked my config for the new kernel, and UNIX-domain sockets and Sys V >> IPC are both enabled in the build. Are there any other possibilities I can >> check? >> >> Thanks, >> Di >> >> -- >> Di Wu (Allan) >> PhD student, VAST Laboratory <http://vast.cs.ucla.edu/>, >> Department of Computer Science, UC Los Angeles >> Email: al...@cs.ucla.edu <mailto:al...@cs.ucla.edu> >> >> On Tue, Nov 25, 2014 at 10:45 AM, Paul Hargrove <phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov>> wrote: >> Allan, >> >> A likely possibility is that some important kernel feature (that Open MPI >> assumes is present) is missing. >> That includes not only "kernel modules" as you mention, but also features >> configure in (or out) of the base kernel. >> For instance, some embedded kernels omit UNIX-domain sockets and SysV IPC >> support. >> >> If you can send me (preferably off-list) the kernel config files for the old >> an new kernels I may be able to spot something. >> If present, you are looking for /boot/config-[VERSION] >> >> -Paul >> >> On Tue, Nov 25, 2014 at 10:25 AM, Allan Wu <al...@cs.ucla.edu >> <mailto:al...@cs.ucla.edu>> wrote: >> I'm sorry I forgot to change the subject when I reply to the digest issue. >> Please find my original email below. >> >> Regards, >> Di >> >> On Tue, Nov 25, 2014 at 10:19 AM, Allan Wu <al...@cs.ucla.edu >> <mailto:al...@cs.ucla.edu>> wrote: >> Thanks Ralph for the reply. Sorry about the log file, I think I forgot to >> put an extension to the file. Please find a new one attached with this >> email. >> >> I'm sorry for not enough debugging information, but 'omp_info' and >> '--debug-devel' are the only ways I know for collecting information, are >> there any other things I can try to provide more info? >> >> When I execute 'mpirun --debug-devel -np 1 ./helloworld', all the output is >> the logging information in my last email. It got stuck at "[fpga1:00718] >> tmp: /tmp", and nothing from my helloworld program is printed out to the >> screen. So I think it is mpirun failing to start my executable, not failing >> to terminate. >> >> I was wondering if this has anything to do with my newer kernel version, >> since it works well in the old case. >> >> Thanks, >> -- >> Di Wu (Allan) >> PhD student, VAST Laboratory <http://vast.cs.ucla.edu/>, >> Department of Computer Science, UC Los Angeles >> Email: al...@cs.ucla.edu <mailto:al...@cs.ucla.edu> >> >> >> Date: Tue, 25 Nov 2014 07:29:51 -0800 >> From: Ralph Castain <r...@open-mpi.org <mailto:r...@open-mpi.org>> >> To: Open MPI Developers <de...@open-mpi.org <mailto:de...@open-mpi.org>> >> Subject: Re: [OMPI devel] OpenMPI v1.8 and v1.8.3 mpirun hangs at >> execution on an embedded ARM Linux kernel version 3.15.0 >> Message-ID: <898cb117-f6a6-4569-89c3-49b75d65b...@open-mpi.org >> <mailto:898cb117-f6a6-4569-89c3-49b75d65b...@open-mpi.org>> >> Content-Type: text/plain; charset="utf-8" >> >> I don?t know what you put in that log file, but it was an executable and I?m >> not feeling that trusting :-) >> >> I?m afraid there isn?t enough debug output there to really tell anything. >> From what little I can see, I?m guessing that the application ran fine and >> you got the usual ?hello? output and the helloworld process exited safely - >> is that correct? And so it is solely mpirun that is failing to cleanly >> terminate? >> >> >> > On Nov 24, 2014, at 11:24 PM, Allan Wu <al...@cs.ucla.edu >> > <mailto:al...@cs.ucla.edu>> wrote: >> > >> > Hello everyone, >> > >> > I have cross-compiled OpenMPI for an embedded ARM Linux. Everything works >> > fine for my system based on Linux 3.8.0. I have previously submitted a >> > post related to my compilation, which can be found here: >> > http://www.open-mpi.org/community/lists/devel/2014/04/14440.php >> > <http://www.open-mpi.org/community/lists/devel/2014/04/14440.php> >> > <http://www.open-mpi.org/community/lists/devel/2014/04/14440.php >> > <http://www.open-mpi.org/community/lists/devel/2014/04/14440.php>>. When I >> > recently upgraded my Linux kernel to 3.15.0, mpirun begins to stuck at >> > even the helloworld program. The program consists only simple APIs: >> > MPI_Init, MPI_Comm_size, MPI_Comm_rank, MPI_Finalize. The problem occurs >> > even at 'mpirun -np 1 ./helloworld', and below are the output with >> > --debug-devel (before it got stuck): >> > [fpga1:00716] sess_dir_finalize: job session dir not empty - leaving >> > [fpga1:00716] procdir: /tmp/openmpi-sessions-root@fpga1_0/63813/0/0 >> > [fpga1:00716] jobdir: /tmp/openmpi-sessions-root@fpga1_0/63813/0 >> > [fpga1:00716] top: openmpi-sessions-root@fpga1_0 >> > [fpga1:00716] tmp: /tmp >> > [fpga1:00718] procdir: /tmp/openmpi-sessions-root@fpga1_0/63813/1/0 >> > [fpga1:00718] jobdir: /tmp/openmpi-sessions-root@fpga1_0/63813/1 >> > [fpga1:00718] top: openmpi-sessions-root@fpga1_0 >> > [fpga1:00718] tmp: /tmp >> > >> > I suspect maybe it is due to incompatible kernel version or some missing >> > kernel modules. I tried also with the latest version 1.8.3, and had the >> > same problem. Does anyone have any thoughts? I have attached the output of >> > 'ompi-info --all' with this email. >> > >> > Please let me know if I need to provide more information. Thanks in >> > advance! >> > >> > Regards, >> > -- >> > Di Wu (Allan) >> > PhD student, VAST?Laboratory <http://vast.cs.ucla.edu/ >> > <http://vast.cs.ucla.edu/>>, >> > Department of Computer Science, UC Los Angeles >> > Email: al...@cs.ucla.edu <mailto:al...@cs.ucla.edu> >> > <mailto:al...@cs.ucla.edu <mailto:al...@cs.ucla.edu>> >> > <log.tar.gz>_______________________________________________ >> > devel mailing list >> > de...@open-mpi.org <mailto:de...@open-mpi.org> >> > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel >> > <http://www.open-mpi.org/mailman/listinfo.cgi/devel> >> > Link to this post: >> > http://www.open-mpi.org/community/lists/devel/2014/11/16330.php >> > <http://www.open-mpi.org/community/lists/devel/2014/11/16330.php> >> >> >> _______________________________________________ >> devel mailing list >> de...@open-mpi.org <mailto:de...@open-mpi.org> >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel >> <http://www.open-mpi.org/mailman/listinfo.cgi/devel> >> Link to this post: >> http://www.open-mpi.org/community/lists/devel/2014/11/16341.php >> <http://www.open-mpi.org/community/lists/devel/2014/11/16341.php> >> >> >> >> -- >> Paul H. Hargrove phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov> >> Computer Languages & Systems Software (CLaSS) Group >> Computer Science Department Tel: +1-510-495-2352 >> <tel:%2B1-510-495-2352> >> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 >> <tel:%2B1-510-486-6900> >> >> >> >> -- >> Paul H. Hargrove phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov> >> Computer Languages & Systems Software (CLaSS) Group >> Computer Science Department Tel: +1-510-495-2352 >> <tel:%2B1-510-495-2352> >> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 >> <tel:%2B1-510-486-6900> >> >> >> >> _______________________________________________ >> devel mailing list >> de...@open-mpi.org <mailto:de...@open-mpi.org> >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel >> <http://www.open-mpi.org/mailman/listinfo.cgi/devel> >> Link to this post: >> http://www.open-mpi.org/community/lists/devel/2014/11/16348.php >> <http://www.open-mpi.org/community/lists/devel/2014/11/16348.php> >> >> >> >> -- >> Paul H. Hargrove phhargr...@lbl.gov >> <mailto:phhargr...@lbl.gov> >> Computer Languages & Systems Software (CLaSS) Group >> Computer Science Department Tel: +1-510-495-2352 >> <tel:%2B1-510-495-2352> >> Lawrence Berkeley National Laboratory Fax: +1-510-486-6900 >> <tel:%2B1-510-486-6900>_______________________________________________ >> devel mailing list >> de...@open-mpi.org <mailto:de...@open-mpi.org> >> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel >> <http://www.open-mpi.org/mailman/listinfo.cgi/devel> >> Link to this post: >> http://www.open-mpi.org/community/lists/devel/2014/11/16349.php >> <http://www.open-mpi.org/community/lists/devel/2014/11/16349.php> > > _______________________________________________ > devel mailing list > de...@open-mpi.org <mailto:de...@open-mpi.org> > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > <http://www.open-mpi.org/mailman/listinfo.cgi/devel> > Link to this post: > http://www.open-mpi.org/community/lists/devel/2014/11/16350.php > <http://www.open-mpi.org/community/lists/devel/2014/11/16350.php> > > > > -- > Paul H. Hargrove phhargr...@lbl.gov > <mailto: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 > _______________________________________________ > devel mailing list > de...@open-mpi.org > Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/devel > Link to this post: > http://www.open-mpi.org/community/lists/devel/2014/11/16351.php
