Ralph and Paul, On 2014/11/26 10:37, Ralph Castain wrote: > So it looks like the issue isn't so much with our code as it is with the OS > stack, yes? We aren't requiring that the loopback be "up", but the stack is > in order to establish the connection, even when we are trying a non-lo > interface. this is correct (imho) > I can look into generating a faster timeout on the socket creation. In the > trunk, we now use unix domain sockets instead of TCP to avoid such issues, > but that won't help with the 1.8 series. i was about to suggest this situation could have been avoided in the first place by using unix domain sockets instead of TCP sockets :-)
is a backport (since this is already available in the trunk/master) simply out of the question ? Cheers, Gilles > >> 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 âEUR"enable-debug? >>> If you can do that, or already have, then letâEUR^(TM)s add the following >>> to the mpirun cmd line: >>> >>> -mca state_base_verbose 10 -mca odls_base_verbose 10 -mca oob_base_verbose >>> 10 >>> >>> YouâEUR^(TM)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 > > > > _______________________________________________ > 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/2014/11/16352.php
