Hello, Answering myself here: checking the revision history, commits 3b8b8c52c519f64cb3ff147db49fcac7cbd0e7d7 or 66c9485e77f7da9a212ae67c88a21f95f13e6652 (in master) seem to relate to this, so I checked using the latest downloadable 3.0.x nightly release, and do not reproduce the issue anymore...
Sorry for the (too-late) report... Yvan ----- Mail original ----- From: "yvan fournier" <yvan.fourn...@free.fr> To: users@lists.open-mpi.org Sent: Sunday January 7 2018 01:52:04 Object: Re: False positives with OpenMPI and memchecker (with attachment) Hello, Sorry, I forgot the attached test case in my previous message... :( Best regards, Yvan Fournier ----- Mail transferred ----- From: "yvan fournier" <yvan.fourn...@free.fr> To: users@lists.open-mpi.org Sent: Sunday January 7 2018 01:43:16 Object: False positives with OpenMPI and memchecker Hello, I obtain false positives with OpenMPI when memcheck is enabled, using OpenMPI 3.0.0 This is similar to an issue I had reported and had been fixed in Nov. 2016, but affects MPI_Isend/MPI_Irecv instead of MPI_Send/MPI_Recv. I had not done much additional testing on my application using memchecker since, so probably may have missed remaining issues at the time. In the attached test (which has 2 optional variants relating to whether the send and receive buffers are allocated on the stack or heap, but exhibit the same basic issue), I have (running "mpicc vg_ompi_isend_irecv.c && -g mpiexec -n 2 ./a.out"): ==19651== Memcheck, a memory error detector ==19651== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==19651== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info ==19651== Command: ./a.out ==19651== ==19650== Thread 3: ==19650== Syscall param epoll_pwait(sigmask) points to unaddressable byte(s) ==19650== at 0x5470596: epoll_pwait (in /usr/lib/libc-2.26.so) ==19650== by 0x5A5A9FA: epoll_dispatch (epoll.c:407) ==19650== by 0x5A5EA9A: opal_libevent2022_event_base_loop (event.c:1630) ==19650== by 0x94C96ED: progress_engine (in /home/yvan/opt/openmpi-3.0/lib/openmpi/mca_pmix_pmix2x.so) ==19650== by 0x5163089: start_thread (in /usr/lib/libpthread-2.26.so) ==19650== by 0x547042E: clone (in /usr/lib/libc-2.26.so) ==19650== Address 0x0 is not stack'd, malloc'd or (recently) free'd ==19650== ==19651== Thread 3: ==19651== Syscall param epoll_pwait(sigmask) points to unaddressable byte(s) ==19651== at 0x5470596: epoll_pwait (in /usr/lib/libc-2.26.so) ==19651== by 0x5A5A9FA: epoll_dispatch (epoll.c:407) ==19651== by 0x5A5EA9A: opal_libevent2022_event_base_loop (event.c:1630) ==19651== by 0x94C96ED: progress_engine (in /home/yvan/opt/openmpi-3.0/lib/openmpi/mca_pmix_pmix2x.so) ==19651== by 0x5163089: start_thread (in /usr/lib/libpthread-2.26.so) ==19651== by 0x547042E: clone (in /usr/lib/libc-2.26.so) ==19651== Address 0x0 is not stack'd, malloc'd or (recently) free'd ==19651== ==19650== Thread 1: ==19650== Invalid read of size 2 ==19650== at 0x4C33BA0: memmove (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==19650== by 0x5A27C85: opal_convertor_pack (in /home/yvan/opt/openmpi-3.0/lib/libopen-pal.so.40.0.0) ==19650== by 0xD177EF1: mca_btl_vader_sendi (in /home/yvan/opt/openmpi-3.0/lib/openmpi/mca_btl_vader.so) ==19650== by 0xE1A7F31: mca_pml_ob1_send_inline.constprop.4 (in /home/yvan/opt/openmpi-3.0/lib/openmpi/mca_pml_ob1.so) ==19650== by 0xE1A8711: mca_pml_ob1_isend (in /home/yvan/opt/openmpi-3.0/lib/openmpi/mca_pml_ob1.so) ==19650== by 0x4EB4C83: PMPI_Isend (in /home/yvan/opt/openmpi-3.0/lib/libmpi.so.40.0.0) ==19650== by 0x108B24: main (vg_ompi_isend_irecv.c:63) ==19650== Address 0x1ffefffcc4 is on thread 1's stack ==19650== in frame #6, created by main (vg_ompi_isend_irecv.c:7) The first 2 warnings seem to relate to initialization, so are not a big issue, but the last one occurs whenever I use MPI_Isend, so they are a more important issue. Using a version built without --enable-memchecker, I also have the two initialization warnings, but not the warning from MPI_Isend... Best regards, Yvan Fournier _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
