Created attachment 509846 [details] ftrace documentation ftrace.txt and events.txt are new docs that Steven updated for MRG Documentation/trace/*. RT Engineering needs to determine what to fold into our Tuning Guide.
Created attachment 509847 [details] Event Tracing Documentation
Hi Beth, Have RT Engineering got a better idea about what to include and leave out from the attached documentation yet? Feel free to redirect the needinfo. Thanks, Alison
http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_MRG/2.0/html-single/Realtime_Tuning_Guide/index.html#sect-Realtime_Tuning_Guide-Realtime_Specific_Tuning-Using_the_ftrace_Utility_for_Tracing_Latencies The "events" are no longer correct in this version. The following comments refer to the ftrace section of the guide Remove "events" from the line below # cat /sys/kernel/debug/tracing/available_tracers events wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none Remove the following section. events Traces system events such as timers, system calls, interrupts, context switches, process wake up and others In the following section substitute "preemptoff" for "events" # echo events > /sys/kernel/debug/tracing/current_tracer In 5. View the trace logs: Remove the following line # cat /sys/kernel/debug/tracing//latency_trace In 6. Change # cat /sys/kernel/debug/tracing//latency_trace > /tmp/lat_trace_log to # cat /sys/kernel/debug/tracing/trace > /tmp/trace_log
This book is now available on redhat.com/docs. Please raise a new bug if you spot any issues. Thanks, LKB