I ran 'make check' under a heavily loaded system, and it hung in qemumonitorjsontest as follows: (gdb) t a a bt Thread 2 (Thread 0x2b0f8000e700 (LWP 423)): #0 0x00000032f96e998d in poll () from /lib64/libc.so.6 #1 0x00002b0f7f3a1951 in virEventPollRunOnce () at util/event_poll.c:615 #2 0x00002b0f7f39fb26 in virEventRunDefaultImpl () at util/event.c:247 #3 0x00000000004c25fa in qemuMonitorTestWorker (opaque=0x1ad8bc0) at qemumonitortestutils.c:308 #4 0x00002b0f7f3bbc39 in virThreadHelper (data=0x1ada580) at util/threads-pthread.c:161 #5 0x00000032f9a07d15 in start_thread () from /lib64/libpthread.so.0 #6 0x00000032f96f246d in clone () from /lib64/libc.so.6 Thread 1 (Thread 0x2b0f7fe0bbc0 (LWP 402)): #0 0x00000032f9a08e60 in pthread_join () from /lib64/libpthread.so.0 #1 0x00002b0f7f3bbeae in virThreadJoin (thread=0x1ad8be8) at util/threads-pthread.c:236 #2 0x00000000004c27b0 in qemuMonitorTestFree (test=0x1ad8bc0) at qemumonitortestutils.c:362 #3 0x00000000004144ba in testQemuMonitorJSONGetMachines (data=0x1ac7650) at qemumonitorjsontest.c:298 #4 0x0000000000414ef2 in virtTestRun (title=0x4c3434 "GetMachines", nloops=1, body=0x413f3e <testQemuMonitorJSONGetMachines>, data=0x1ac7650) at testutils.c:160 ---Type <return> to continue, or q <return> to quit--- #5 0x00000000004149f4 in mymain () at qemumonitorjsontest.c:446 #6 0x0000000000416092 in virtTestMain (argc=1, argv=0x7fffc02dcac8, func=0x41493d <mymain>) at testutils.c:719 #7 0x0000000000414aab in main (argc=1, argv=0x7fffc02dcac8) at qemumonitorjsontest.c:455 This was with latest libvirt.git, so I'm worried we still have a nasty race somewhere in there. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org