Re: [PATCH] selftests: ftrace: Use md5sum to take less time of checking logs

[Shuah Khan]

On 06/28/2017 08:17 AM, Steven Rostedt wrote:
> On Tue, 27 Jun 2017 19:28:32 +0900
> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
> 
>> Use md5sum so that it takes less time of checking
>> trace logs update. Since busybox tail/cat takes too
>> long time to read the trace log, this uses md5sum
>> to check whether trace log is updated or not.
> 
> How much faster is md5sum? I can see this causing issues in other
> environments.
> 
> -- Steve

Sorry Steve. I pulled this into linux-ksefltest next. Are you concerned
about any specific environments? I can try this out and see if it is a
problem.

thanks,
-- Shuah

> 
>>
>> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
>> ---
>>  .../test.d/ftrace/func_traceonoff_triggers.tc      |    6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
>> index 9cf3852..7a9ab4f 100644
>> --- a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
>> +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc
>> @@ -103,11 +103,11 @@ if [ $on != "0" ]; then
>>      fail "Tracing is not off"
>>  fi
>>  
>> -line1=`cat trace | tail -1`
>> +csum1=`md5sum trace`
>>  sleep $SLEEP_TIME
>> -line2=`cat trace | tail -1`
>> +csum2=`md5sum trace`
>>  
>> -if [ "$line1" != "$line2" ]; then
>> +if [ "$csum1" != "$csum2" ]; then
>>      fail "Tracing file is still changing"
>>  fi
>>  
> 
> 
>