hi,

i'm trying to trace a possible latency issue using ftrace with a
2.6.27 kernel on a x86 platform, but there seems to be something that
i'm missing

i do the following:

cat available_tracers
wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none

echo 0 > tracing_enabled

echo irqsoff > current_tracer

echo 1 > tracing_enabled

<do stuff>

echo 0 > tracing_enabled

cat latency_trace
# tracer: irqsoff
#

cat trace
# tracer: irqsoff
#
#           TASK-PID   CPU#    TIMESTAMP  FUNCTION
#              | |      |          |         |

cat tracing_max_latency
-1

i tried it also with preemptoff and preemptirqsoff, with the same
result. the 'ftrace' tracer works as expected (ftrace is quite
impressive btw)

any clue what i am doing wrong?

 
-- 
Matthias Kaehlcke
Embedded Linux Engineer
Barcelona

  Control over the use of one's ideas really constitutes control over other
  people's lives; and it is usually used to make their lives more difficult.
                          (Richard Stallman)
                                                                 .''`.
    using free software / Debian GNU/Linux | http://debian.org  : :'  :
                                                                `. `'`
gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4                  `-

--
To unsubscribe from this list: send an email with
"unsubscribe kernelnewbies" to [EMAIL PROTECTED]
Please read the FAQ at http://kernelnewbies.org/FAQ

Reply via email to