Using the trace-cmd, KernelShark, and perf-tools ftrace frontends

There's no doubt that the Linux kernel ftrace infrastructure is immensely powerful, enabling you to look deep inside the kernel, throwing light into the dark corners of the system, as it were. This power does come at the cost of a somewhat steep learning curve – lots of sysfs-based tuning and options knobs that you need to be intimately aware of, plus the burden of filtering a possibly huge amount of noise in the resulting traces (as you'd have already learned from the previous sections of this chapter!). Steven Rostedt thus built a powerful and elegant command-line-based frontend to ftrace, trace-cmd. What's more, there's a true GUI frontend to trace-cmd itself, the KernelShark program. It parses the trace data recorded (trace.dat by default) by trace-cmd and displays it in a more human-digestible GUI. In a similar manner, Brendan Gregg has built the perf-tools script-based frontend project...