On 03/09/2012 04:13 PM, Stefan Hajnoczi wrote: > The kvm kernel module includes a number of trace events which can be > useful when debugging system behavior. Even on production systems these > trace events can be used to observe guest behavior and identify the > source of problems. > > The kvm_flightrecorder script is a command-line wrapper for the > /sys/kernel/debug/tracing interface. Kernel symbols do not need to be > installed. > > This script captures a fixed-size buffer of KVM trace events. Recent > events overwrite the oldest events when the buffer size is exceeded and > it is possible to leave KVM tracing enabled for any period of time with > just a fixed-size buffer. If the buffer is large enough this script is > a useful tool for collecting detailed information after an issue occurs > with a guest. Hence the name "flight recorder". > > The script can also be used in 'tail' mode to simply view KVM trace > events as they occur. This is handy for development and to ensure that > the guest is indeed running. > >
Have you considered updating trace-cmd or perf-something instead? While each of these tools are useful we miss out on combining capabilities. For example you could 'perf probe' a dynamic tracepoint and flightrecord it together with kvm tracepoints. -- error compiling committee.c: too many arguments to function
