Reply-To: shuah@kernel.org
Subject: Re: [PATCH] selftests: ftrace: Use md5sum to take less time of
 checking logs
To: Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-kselftest@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
        linux-kernel@vger.kernel.org, Shuah Khan <shuah@kernel.org>
References: <149855930170.10335.7114289594738299220.stgit@devbox>
 <20170628101728.5a41bed0@gandalf.local.home>
From: Shuah Khan <shuah@kernel.org>
Message-ID: <8f6497e7-8236-f0e0-0f51-87d691b9df8b@kernel.org>
Date: Wed, 28 Jun 2017 08:30:24 -0600
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On 06/28/2017 08:17 AM, Steven Rostedt wrote:
> On Tue, 27 Jun 2017 19:28:32 +0900
> Masami Hiramatsu <mhiramat@kernel.org> 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@kernel.org>
>> ---
>>  .../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
>>  
> 
> 
>