Hui, I’d like to trap segfaults so that the process that raised them can be shut down gracefully/finalized without taking down the whole MPI job. Maybe you are right and I shouldn’t trap them. However, when I install my signal handlers, I check if MPI already has a signal handler installed for each of them. It isn’t reporting that MPI has done so. Perhaps my code is incorrect? setUpOneHandler(const int signum) { struct sigaction sa_new, sa_old; sa_new.sa_handler = mpiSignalHandler; sa_new.sa_flags = 0; sigemptyset(&sa_new.sa_mask); if (sigaction(signum, NULL, &sa_old) < 0) { // ERROR: could not query old handler } else if (sa_old.sa_handler == SIG_IGN || sa_old.sa_handler == SIG_DFL) { // MPI hasn't set its own handler for this signal, so we // will install our own. if (sigaction(signum, &sa_new, NULL) < 0) { // ERROR: could not set new handler } } else { // MPI already has a handler installed for this signal. Do nothing } } From: Zhou, Hui <[email protected]> Sent: Monday, April 6, 2020 2:08 PM To: Mccall, Kurt E. (MSFC-EV41) <[email protected]>; [email protected] Subject: [EXTERNAL] Re: [mpich-discuss] Abnormal termination on Linux Thanks, Kurt. I think the reason your signal trap didn’t work is because `mpiexec` is trapping it first. Segfault is code error. Why would you want to trap it? -- Hui Zhou From: "Mccall, Kurt E. (MSFC-EV41)" <[email protected]<mailto:[email protected]>> Date: Monday, April 6, 2020 at 1:52 PM To: "Zhou, Hui" <[email protected]<mailto:[email protected]>>, "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Subject: RE: [mpich-discuss] Abnormal termination on Linux Hui, Sorry for not mentioning that. MPICH 3.3.2 compiled with pgc++ 19.5. Kurt From: Zhou, Hui <[email protected]<mailto:[email protected]>> Sent: Monday, April 6, 2020 12:58 PM To: [email protected]<mailto:[email protected]> Cc: Mccall, Kurt E. (MSFC-EV41) <[email protected]<mailto:[email protected]>> Subject: [EXTERNAL] Re: [mpich-discuss] Abnormal termination on Linux Which version of MPICH were you running? -- Hui Zhou From: "Mccall, Kurt E. (MSFC-EV41) via discuss" <[email protected]<mailto:[email protected]>> Reply-To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Date: Monday, April 6, 2020 at 12:45 PM To: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>> Cc: "Mccall, Kurt E. (MSFC-EV41)" <[email protected]<mailto:[email protected]>> Subject: Re: [mpich-discuss] Abnormal termination on Linux I should mention that I am unable to predict in which node or process the abnormal termination occurs, so I can’t practically attach a debugger and try to intercept the error. Kurt From: Mccall, Kurt E. (MSFC-EV41) <[email protected]<mailto:[email protected]>> Sent: Monday, April 6, 2020 11:50 AM To: [email protected]<mailto:[email protected]> Cc: Mccall, Kurt E. (MSFC-EV41) <[email protected]<mailto:[email protected]>> Subject: Abnormal termination on Linux I have a couple of questions about abnormal termination. The EXIT CODE below is 11, which could be signal SIGSEGV, or is it something defined by MPICH? If it is SIGSEGV, it is strange because my signal handler isn’t catching it and cleaning up properly (the signal handler calls MPI_Finalize()). Is there any way to get more information about the location of the error? = BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES = PID 14385 RUNNING AT n020.cluster.com = EXIT CODE: 11 = CLEANING UP REMAINING PROCESSES = YOU CAN IGNORE THE BELOW CLEANUP MESSAGES Thanks, Kurt