> What's the chrt for? We often need simple test to get latency result of realtime using "current_tracers" file. In this case, We can run easy testcase as realtime task with the chrt command. Although we usually use function tracer for tracing internal kernel functions by ftraced. I think that we need simple example like the chrt for monitoring latencies and the kernel functoins using sleep command as realtime task. 2009/4/7 Steven Rostedt <srostedt@xxxxxxxxxx>: > > On Mon, 2009-04-06 at 23:17 +0900, GeunSik Lim wrote: >> I attached patch file again because no-operation is changed >> from "none"word to "nop" word. >> >> for example, >> - "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" >> + "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n" >> >> ./trace_nop.c:struct tracer nop_trace __read_mostly = >> .name = "nop", >> .init = nop_trace_init, >> .reset = nop_trace_reset, >> .selftest = trace_selftest_startup_nop, >> .flags = &nop_flags, >> .set_flag = nop_set_flag >> >> >> >> 2009/4/6 GeunSik Lim <leemgs1@xxxxxxxxx>: >> > Dear Steven, >> > >> > The author of ftrace(Internal kernel Function Tracer) feature >> > renamed the ftrace tracer >> > to function to avoid further confusion between the ftrace >> > infrastructure and the >> > function tracer on Oct-20, 2008. >> > >> > But, Update of Mini-HOWTO document are still not working >> > . >> > Most of the developers often utilize "/debug/tracing/README" file >> > as Mini-HOWTO. >> > They will confuse definition and usage about ftrace between >> > README(ftrace) file >> > and available_tracers(function) file after linux-2.6.27 like me. >> > And, I want you to append "chrt -f 5 sleep 1" command as simple >> > example for latency. >> > >> > Signed-off-by: GeunSik Lim <leemgs1@xxxxxxxxx> >> > Signed-off-by: Steven Rostedt <srostedt@xxxxxxxxxx> >> > Signed-off-by: Ingo Molnar <mingo@xxxxxxx> >> > --- >> > kernel/trace/trace.c | 3 ++- >> > 1 files changed, 2 insertions(+), 1 deletions(-) >> > >> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c >> > index a0174a4..15f0eec 100644 >> > --- a/kernel/trace/trace.c >> > +++ b/kernel/trace/trace.c >> > @@ -2358,7 +2358,7 @@ static const char readme_msg[] = >> > "# mkdir /debug\n" >> > "# mount -t debugfs nodev /debug\n\n" >> > "# cat /debug/tracing/available_tracers\n" >> > - "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" >> > + "wakeup preemptirqsoff preemptoff irqsoff function >> > sched_switch none\n\n" >> > "# cat /debug/tracing/current_tracer\n" >> > "none\n" >> > "# echo sched_switch > /debug/tracing/current_tracer\n" >> > @@ -2368,6 +2368,7 @@ static const char readme_msg[] = >> > "noprint-parent nosym-offset nosym-addr noverbose\n" >> > "# echo print-parent > /debug/tracing/trace_options\n" >> > "# echo 1 > /debug/tracing/tracing_enabled\n" >> > + "# chrt -f 5 sleep 1\n" > > > What's the chrt for? > > -- Steve > > > -- Regards, GeunSik Lim -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
