Re: ftrace not working?

From: KOSAKI Motohiro
Date: Mon Mar 23 2009 - 04:09:25 EST


Hi

> I tried ftrace with the linus git 2.6.29 rc-6, & rc-8, but I always seem to
> get empty trace! Am I doing something wrong?
>
> This is what I did.
>
> linux-glcc:/data/git/linux-2.6 # cd /sys/kernel/debug/tracing/
> linux-glcc:/sys/kernel/debug/tracing # cat available_tracers
> function_graph function sysprof sched_switch nop
> linux-glcc:/sys/kernel/debug/tracing # echo sched_switch > current_tracer
> linux-glcc:/sys/kernel/debug/tracing # echo 1 > tracing_enabled
> linux-glcc:/sys/kernel/debug/tracing # cat tracing_enabled
> 1
> linux-glcc:/sys/kernel/debug/tracing # cat trace
> # tracer: sched_switch
> #
> # TASK-PID CPU# TIMESTAMP FUNCTION
> # | | | | |

your operation seems fine and your .config seems fine too.
but my box works ftrace well on 2.6.29-rc8.

hmm...

Could you post followin operation result and dmesg?

# cat failures
# cat current_tracer
# cat trace_options
# cat buffer_size_kb
# cat dyn_ftrace_total_info
# cat trace_options
# cat set_ftrace_filter
# cat tracing_cpumask
# cat tracing_enabled
# cat tracing_on



--
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/