selftests/ftrace: traceonoff_triggers: strip off names

selftests/ftrace: traceonoff_triggers: strip off names

The func_traceonoff_triggers.tc sometimes goes to fail
on my board, Kunpeng-920.

[root@localhost]# ./ftracetest ./test.d/ftrace/func_traceonoff_triggers.tc -l fail.log
=== Ftrace unit tests ===
[1] ftrace - test for function traceon/off triggers     [FAIL]
[2] (instance)  ftrace - test for function traceon/off triggers [UNSUPPORTED]

I look up the log, and it shows that the md5sum is different between csum1 and csum2.

++ cnt=611
++ sleep .1
+++ cnt_trace
+++ grep -v '^#' trace
+++ wc -l
++ cnt2=611
++ '[' 611 -ne 611 ']'
+++ cat tracing_on
++ on=0
++ '[' 0 '!=' 0 ']'
+++ md5sum trace
++ csum1='76896aa74362fff66a6a5f3cf8a8a500  trace'
++ sleep .1
+++ md5sum trace
++ csum2='ee8625a21c058818fc26e45c1ed3f6de  trace'
++ '[' '76896aa74362fff66a6a5f3cf8a8a500  trace' '!=' 'ee8625a21c058818fc26e45c1ed3f6de  trace' ']'
++ fail 'Tracing file is still changing'
++ echo Tracing file is still changing
Tracing file is still changing
++ exit_fail
++ exit 1

So I directly dump the trace file before md5sum, the diff shows that:

[root@localhost]# diff trace_1.log trace_2.log -y --suppress-common-lines
dockerd-12285   [036] d.... 18385.510290: sched_stat | <...>-12285   [036] d.... 18385.510290: sched_stat
dockerd-12285   [036] d.... 18385.510291: sched_swit | <...>-12285   [036] d.... 18385.510291: sched_swit
<...>-740       [044] d.... 18385.602859: sched_stat | kworker/44:1-740 [044] d.... 18385.602859: sched_stat
<...>-740       [044] d.... 18385.602860: sched_swit | kworker/44:1-740 [044] d.... 18385.602860: sched_swit

And we can see that <...> filed be filled with names.

We can strip off the names there to fix that.

After strip off the names:

kworker/u257:0-12 [019] d..2.  2528.758910: sched_stat | -12 [019] d..2.  2528.758910: sched_stat_runtime: comm=k
kworker/u257:0-12 [019] d..2.  2528.758912: sched_swit | -12 [019] d..2.  2528.758912: sched_switch: prev_comm=kw
<idle>-0          [000] d.s5.  2528.762318: sched_waki | -0  [000] d.s5.  2528.762318: sched_waking: comm=sshd pi
<idle>-0          [037] dNh2.  2528.762326: sched_wake | -0  [037] dNh2.  2528.762326: sched_wakeup: comm=sshd pi
<idle>-0          [037] d..2.  2528.762334: sched_swit | -0  [037] d..2.  2528.762334: sched_switch: prev_comm=sw

Link: https://lore.kernel.org/r/20230818013226.2182299-1-zouyipeng@huawei.com
Fixes: d87b29179aa0 ("selftests: ftrace: Use md5sum to take less time of checking logs")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>