Linux Low-Latency Tracing for Multicore Hard Real-Time Systems

Table 2

Statistics per loop, in nanoseconds, generated by npt for loops on both standard and PREEMPT_RT patched kernels for both LTTng-UST 2.2 and SystemTap 2.2.1.

Kernel	Latencies in ns
	Standard		PREEMPT_RT patched
Tracer	LTTng	SystemTap	LTTng	SystemTap
Minimum	270.0	581.6	262.5	911.2
Mean	498.2	777.0	497.6	1028
Maximum	82 180	1 498 000	35 260	1 476 000
Variance	3.620	23.36	4.872	33.74
std deviation	60.17	152.8	69.80	183.7