Part III Kernel monitoring #
- 4 SystemTap—filtering and analyzing system data
- 5 Kernel probes
- 6 Hardware-based performance monitoring with Perf
Perf is an interface to access the performance monitoring unit (PMU) of a processor and to record and display software events such as page faults. It supports system-wide, per-thread, and KVM virtualization guest monitoring.
- 7 OProfile—system-wide profiler
OProfile is a profiler for dynamic program analysis. It investigates the behavior of a running program and gathers information. This information can be viewed and gives hints for further optimization.
It is not necessary to recompile or use wrapper libraries to use OProfile. Not even a kernel patch is needed. Usually, when profiling an application, a small overhead is expected, depending on the workload and sampling frequency.
- 8 Dynamic debug—kernel debugging messages
Dynamic debug is a powerful debugging feature in the Linux kernel that allows you to enable and disable debugging messages at runtime without the need to recompile the kernel or reboot the system.