Good. BTW, we do repeated long-term tests 14 times per day with a single kvm guest that runs on two cores and conducts a number of CPU benchmarks. (https://www.osadl.org/?id=931) - never had this problem. So it may be related to running more than a single kvm guest.I can quite reliably trigger this cpu stall error now. Just try to start several KVM guests.
[..] Are there any way I can use to narrow down this error?
cd /sys/kernel/debug/tracing/ echo 0 >tracing_on echo 1 >events/enable echo function >current_tracer echo 14080 >buffer_size_kb echo 1 >tracing_on while true do if dmesg | tail -100 | grep -q "rcu_preempt detected stalls" then echo 0 >tracing_on break fi sleep 1 done Then start the kvm quests. Alternatively, you may use the kernel parameter ftrace_dump_on_oops.If the problem no longer occurs or behaves differently, try to reduce the debug output step be step, e.g. disable less important events and specify selected available_filter_functions in set_ftrace_filter.
When the problem can be reproduced and the system stalls the way you observed earlier, enter
cat trace >/tmp/trace.txt and try to find out what is going on. If you need help, compress the trace bzip2 trace.txtupload trace.txt.bz2 to the Internet for inspection and post the related URL.
-Carsten. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html