[lttng-dev] epoll_wait reboot kernel?

[zhenyu.ren]

Hi,lttng-dev

   I am working on rhel6(2.6.32.220) and ust is working very well.But when I use lttng-modules (after "lttng start"),the kernel reboots immediately without any message output to console. 

  It took me some days finding out what results in reboot. I shortcut __event_probe__##_name() before _tstruct but kernel still reboot(So what left is  metadata_printf).If I comment out "mask |= POLLIN" in lttng_metadata_ring_buffer_poll() ,kernel do not reboot. What I find out is before reboot the callchain of  lttng-consumerd thread is consumer_thread_metadata_poll()->lttng_poll_wait(wait for metadata stream)->compat_epoll_wait().

  I want to use poll instead as epoll in lttng-tools ,I changed lttng-tools configure file to not use epoll(undef HAVE_EPOLL),but "lttng enable-event -a -k "failed :(Do I miss anything?)
#lttng enable-event -a -k
DEBUG1 [17837/18080]: Wait for client response (in thread_manage_clients() at main.c:3709)
DEBUG1 [17837/18080]: Receiving data from client ... (in thread_manage_clients() at main.c:3754)
DEBUG1 [17837/18080]: Nothing recv() from client... continuing (in thread_manage_clients() at main.c:3758)
DEBUG1 [17837/18080]: Clean command context structure (in clean_command_ctx() at main.c:535)
DEBUG1 [17837/18080]: Accepting client command ... (in thread_manage_clients() at main.c:3667)
DEBUG1 [17837/18080]: Wait for client response (in thread_manage_clients() at main.c:3709)
DEBUG1 [17837/18080]: Receiving data from client ... (in thread_manage_clients() at main.c:3754)
DEBUG1 [17837/18080]: Processing client command 7 (in process_client_msg() at main.c:2579)
DEBUG1 [17837/18080]: Getting session k-test by name (in process_client_msg() at main.c:2656)
DEBUG1 [17837/18080]: Creating kernel session (in create_kernel_session() at main.c:2495)
DEBUG3 [17837/18080]: Created hashtable size 4 at 0x669410 of type 1 (in lttng_ht_new() at hashtable.c:112)
DEBUG1 [17837/18080]: Kernel session created (fd: 21) (in kernel_create_session() at kernel.c:109)
DEBUG3 [17837/18080]: Copying tracing session consumer output in kernel session (in copy_session_consumer() at main.c:2393)
DEBUG3 [17837/18080]: Created hashtable size 4 at 0x66a750 of type 1 (in lttng_ht_new() at hashtable.c:112)
DEBUG3 [17837/18080]: Copy session consumer subdir /kernel (in copy_session_consumer() at main.c:2428)
DEBUG3 [17837/18080]: mkdir() recursive /root/lttng-traces/k-test-20140222-131335 with mode 504 for uid 0 and gid 0 (in run_as_mkdir_recursive() at runas.c:310)
DEBUG1 [17837/18080]: Using run_as_clone (in run_as() at runas.c:293)
lttng-sessiond: ht-cleanup.c:92: thread_ht_cleanup: Assertion `pollfd == ht_cleanup_pipe[0]' failed.

  It seems lttng-tools  in ubuntu 12.04 is using poll,isnt it?

  Does anyone have any suggestions to me ?

PS:.lttng(ust/module/tool) version is 2.3.0 and urcu version is 0.8

Thanks in advance
zhenyu.ren