scripts/tracing: fix the bug that can't parse raw_trace_func

Since commit 77271ce4b2c0 ("tracing: Add irq, preempt-count and need resched info
to default trace output"), the default trace output format has been changed to:
          <idle>-0       [009] d.h. 22420.068695: _raw_spin_lock_irqsave <-hrtimer_interrupt
          <idle>-0       [000] ..s. 22420.068695: _nohz_idle_balance <-run_rebalance_domains
          <idle>-0       [011] d.h. 22420.068695: account_process_tick <-update_process_times

origin trace output format:(before v3.2.0)
     # tracer: nop
     #
     #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
     #              | |       |          |         |
          migration/0-6     [000]    50.025810: rcu_note_context_switch <-__schedule
          migration/0-6     [000]    50.025812: trace_rcu_utilization <-rcu_note_context_switch
          migration/0-6     [000]    50.025813: rcu_sched_qs <-rcu_note_context_switch
          migration/0-6     [000]    50.025815: rcu_preempt_qs <-rcu_note_context_switch
          migration/0-6     [000]    50.025817: trace_rcu_utilization <-rcu_note_context_switch
          migration/0-6     [000]    50.025818: debug_lockdep_rcu_enabled <-__schedule
          migration/0-6     [000]    50.025820: debug_lockdep_rcu_enabled <-__schedule

The draw_functrace.py(introduced in v2.6.28) can't parse the new version format trace_func,
So we need modify draw_functrace.py to adapt the new version trace output format.

Link: https://lkml.kernel.org/r/20210611022107.608787-1-suhui@zeku.com
Cc: stable@vger.kernel.org
Fixes: 77271ce4b2c0 tracing: Add irq, preempt-count and need resched info to default trace output
Signed-off-by: Hui Su <suhui@zeku.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/scripts/tracing/draw_functrace.py b/scripts/tracing/draw_functrace.py
index 74f8aad..7011fbe 100755 (executable)
--- a/scripts/tracing/draw_functrace.py
+++ b/scripts/tracing/draw_functrace.py
@@ -17,7 +17,7 @@ Usage:
        $ cat /sys/kernel/debug/tracing/trace_pipe > ~/raw_trace_func
        Wait some times but not too much, the script is a bit slow.
        Break the pipe (Ctrl + Z)
-       $ scripts/draw_functrace.py < raw_trace_func > draw_functrace
+       $ scripts/tracing/draw_functrace.py < ~/raw_trace_func > draw_functrace
        Then you have your drawn trace in draw_functrace
 """
 
@@ -103,10 +103,10 @@ def parseLine(line):
        line = line.strip()
        if line.startswith("#"):
                raise CommentLineException
-       m = re.match("[^]]+?\\] +([0-9.]+): (\\w+) <-(\\w+)", line)
+       m = re.match("[^]]+?\\] +([a-z.]+) +([0-9.]+): (\\w+) <-(\\w+)", line)
        if m is None:
                raise BrokenLineException
-       return (m.group(1), m.group(2), m.group(3))
+       return (m.group(2), m.group(3), m.group(4))
 
 
 def main():