[The historical notes are removed and replaced by partial trace information from example hang-ups, not that I've figured out what contributes yet.] I ran into the following while trying to get evidence about the hang-up for an amd64->armv7 cross-build of multimedia/gstreamer1-qt_at_qt5 . The following from trying to get evidence for the hang-up via a manual run of "make multimedia/gstreamer1-qt FLAVOR=qt5” in a poudriere bulk -i’s interactive mode for the context that has the hang-up in normal poudriere-devel runs. From top after the hang-up (to identify some context): 14528 root 2 52 0 100M 24M 0 kqread 11 0:00 0.00% /usr/local/bin/qemu-arm-static /usr/local/bin/cmake -E cmake_autogen /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/. 14527 root 2 52 0 88M 13M 0 select 22 0:00 0.00% /usr/local/bin/qemu-arm-static ninja -j1 -v all from ps -auxd as well (to identify more context): root 10114 0.0 0.0 10328 1756 1 I+J 13:47 0:00.01 | `-- make FLAVOR=qt5 root 14526 0.0 0.0 10204 1792 1 I+J 13:50 0:00.00 | `-- /bin/sh -e -c (cd /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build; if ! /usr/bin/env QT_SELE root 14527 0.0 0.0 90304 13084 1 I+J 13:50 0:00.09 | `-- /usr/local/bin/qemu-arm-static ninja -j1 -v all root 14528 0.0 0.0 102876 25060 1 IJ 13:50 0:00.12 | `-- /usr/local/bin/qemu-arm-static /usr/local/bin/cmake -E cmake_autogen /wrkdirs/usr/ports/multimedia/g I had made a qemu-user-static that enabled do_strace when it is used to run cmake or ninja. The only do_strace lines from qemu-arm-static running cmake or ninja mentioning process 14528 are included in the sequence: (Before the below was a long list of "14527 fstatat” lines. I’ll note that "'Unknown syscall 545” is from ppoll use.) 82400 sigprocmask(1,-1610620016,-191968524,-186261416,0,24) = 0 82400 sigaction(2,-1610620040,-191968596,-186261584,210460,0) = 0 82400 sigaction(15,-1610620040,-191968572,-186261584,210460,0) = 0 82400 sigaction(1,-1610620040,-191968548,-186261584,210460,0) = 0 82400 gettimeofday(-1610619984,0,4,-186261584,-1610619440,-1610619528) = 0 82400 gettimeofday(-1610619984,0,4,359949,1545969996,0) = 0 82400 gettimeofday(-1610620120,0,4,2,-184666112,-1610619520) = 0 82400 fstatat(-100,"elements/gstqtvideosink/CMakeFiles", 0x9fffe200, 0) = 0 82400 fstatat(-100,"elements/gstqtvideosink/gstqt5videosink_autogen", 0x9fffe200, 0) = 0 82400 pipe2(-1610620176,0,-1610620108,0,-1610620120,167084) = 0 82400 fcntl(5,1,-1610620108,-185863932,-192200556,-1610620228) = 0 82400 fcntl(5,2,1,-185863932,-192200556,-1610620228) = 0 82400 vfork(0,66450,-186876196,-1610620184,-1610620240,0) = 82401 82400 close(6) = 0 = 0 82400 Unknown syscall 545 82401 setpgid(0,0,-186876196,-1610620184,-1610620240,0) = 0 82401 sigprocmask(3,-191586912,0,-1610620184,-1610620240,0) = 0 82401 close(5) = 0 82401 open("/dev/null",0,0) = 5 82401 dup2(5,0,0,-1610620184,-1610620240,0) = 0 82401 close(5) = 0 82401 fcntl(0,2,0,-1610620184,-1610620240,0) = 0 82401 dup2(6,1,0,-1610620184,-1610620240,0) = 1 82401 fcntl(1,2,0,-1610620184,-1610620240,0) = 0 82401 dup2(6,2,0,-1610620184,-1610620240,0)82400 sigpending(-1610620072,1,0,-191968524,0,0) = 0 The vfork then close(6) sequence for 82400 vs. the later use of 6 in dup2 in 82401 may be rather odd. But it looks like qemu-*-static uses do_freebsd_fork to implement do_freebsd_vfork, despite reporting vfork before calling do_freebsd_vfork. (Does the close(6) appear to indicate a race for native operation of ninja for the period when the address space is shared?) Ninja has Subprocess::Start code that has: #ifdef POSIX_SPAWN_USEVFORK flags |= POSIX_SPAWN_USEVFORK; #endif if (posix_spawnattr_setflags(&attr, flags) != 0) Fatal("posix_spawnattr_setflags: %s", strerror(errno)); const char* spawned_args[] = { "/bin/sh", "-c", command.c_str(), NULL }; if (posix_spawn(&pid_, "/bin/sh", &action, &attr, const_cast<char**>(spawned_args), environ) != 0) Fatal("posix_spawn: %s", strerror(errno)); that is in use here. I think that this explains the vfork use. It turns out that putting the hung-up build in the background and then killing 82401 with the likes of kill -6 leads to more output that had apparently been buffered. It shows the use of the (amd64 native) /bin/sh that in turn leads to /usr/local/bin/cmake via qemu-arm-static. /bin/sh, being native, gets no do_strace output from qemu-arm-static. 82400 sigpending(-1610620072,1,0,-191968524,0,0) = 0 82400 read(5,0x9fffd368,4096) = 58 82400 Unknown syscall 545 82400 sigpending(-1610620072,1,0,-191968524,0,0) = 0 82400 read(5,0x9fffd368,4096) = 0 82400 close(5) = 0 82400 wait4(82401,-1610620004,0,0,-191968640,0) = 82401 82400 mmap(0,86016,3,201330690,-1,-1610620169) = 0xf4777000 82400 gettimeofday(-1610620224,0,4,-1610619944,31,16777216) = 0 82400 write(1,0xf4950000,283)[1/129] cd /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink && /usr/local/bin/cmake -E cmake_autogen /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink/CMakeFiles/gstqt5videosink_autogen.dir/AutogenInfo.cmake Debug = 283 82400 write(1,0xf4950000,137)FAILED: elements/gstqtvideosink/CMakeFiles/gstqt5videosink_autogen elements/gstqtvideosink/gstqt5videosink_autogen/mocs_compilation.cpp = 137 82400 write(1,0xf4950000,275)cd /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink && /usr/local/bin/cmake -E cmake_autogen /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink/CMakeFiles/gstqt5videosink_autogen.dir/AutogenInfo.cmake Debug = 275 82400 write(1,0xf4950000,5) = 2 = 5 (Note that some 82400 writes are reporting 82401 information:) 82400 write(1,0xf4950000,49)82401 fcntl(2,2,0,-1610620184,-1610620240,0) = 0 = 49 82400 write(1,0xf4950000,19)82401 close(6) = 0 = 19 82400 write(1,0xf4950000,401)82401 execve("/bin/sh",{"/bin/sh","-c","cd /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink && /usr/local/bin/cmake -E cmake_autogen /wrkdirs/usr/ports/multimedia/gstreamer1-qt/work-qt5/.build/elements/gstqtvideosink/CMakeFiles/gstqt5videosink_autogen.dir/AutogenInfo.cmake Debug",NULL})82401 __sysctl({ 0 3 }, 2, 0x9fffda80, 0x9fffdf64, 0xf5002097, 0x0000000c) = 0 = 401 (The /bin/sh activity is not logged: /bin/sh is native amd64 code here. The below is from the later /usr/local/bin/cmake via qemu-arm-static. . . . (much omitted) . . . 82400 write(1,0xf4950000,60)82401 mmap(0,28672,3,201330690,-1,-1610621989) = 0xf41a0000 = 60 82400 write(1,0xf4950000,74)82401 clock_gettime(4,-1610621832,4,-199622492,-199622492,-199622656) = 0 = 74 82400 write(1,0xf4950000,62)82401 kqueue(-199622656,0,53102,0,-199622656,-1610621444) = 3 = 62 82400 write(1,0xf4950000,81)82401 ioctl(3, 0x20006601 { IO GRP:0x66('f') CMD:1 LEN:0 }, 0x0000cf6e, ...) = 0 = 81 . . . (some omitted) . . . (Then there is a fairly long sequence of access's and then a sequence of fstatat's just before:) 82400 write(1,0xf4950000,32)82401 write(9,0xf4e1a945,1) = 1 = 32 82400 write(1,0xf4950000,61)82401 clock_gettime(4,-1610622624,4,100863,1,-199483392) = 0 = 61 82400 write(1,0xf4950000,106)82401 kevent(3,-1610688200,2,-1610688200,1024,0)qemu: uncaught target signal 6 (Abort trap) - core dumped = 106 82400 write(1,0xf4950000,41)ninja: build stopped: subcommand failed. = 41 So it was hung at the kevent until the kill -6 . Via another experiment ninja was at the time waiting in ppoll: Reading symbols from ninja...done. [New LWP 73023] Core was generated by `ninja'. Program terminated with signal SIGABRT, Aborted. #0 0xf4e5e0dc in _ppoll () from /lib/libc.so.7 (gdb) bt #0 0xf4e5e0dc in _ppoll () from /lib/libc.so.7 #1 0x00033bf0 in SubprocessSet::DoWork (this=<optimized out>) at src/subprocess-posix.cc:237 Backtrace stopped: previous frame inner to this frame (corrupt stack?) === Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)Received on Fri Dec 28 2018 - 07:16:54 UTC
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