Preemption-off Latency Tracer
modulename: trace_irqsoff.ko
configname: CONFIG_PREEMPT_TRACER
Linux Kernel Configuration
└─>Kernel hacking
└─>Tracers
└─>Preemption-off Latency Tracer
In linux kernel since version 2.6.27 (release Date: 2008-10-09)
This option measures the time spent in preemption-off critical
sections, with microsecond accuracy.
The default measurement method is a maximum search, which is
disabled by default and can be runtime (re-)started
via:
echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increase with this option
enabled. This option and the irqs-off timing option can be
used together or separately.)
sections, with microsecond accuracy.
The default measurement method is a maximum search, which is
disabled by default and can be runtime (re-)started
via:
echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increase with this option
enabled. This option and the irqs-off timing option can be
used together or separately.)