Re: [PATCH 0/7] selftests/ftrace: Some improvements of ftracetest

From: Shuah Khan
Date: Wed Jun 14 2017 - 10:17:53 EST


Hi Masami,

On 06/13/2017 10:53 PM, Masami Hiramatsu wrote:
> On Wed, 14 Jun 2017 11:12:17 +0900
> Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
>
>> Hi Shuah and Steve,
>>
>> Sorry for replying so late...
>>
>> On Thu, 8 Jun 2017 17:51:44 -0400
>> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>>
>>> On Thu, 8 Jun 2017 15:44:08 -0600
>>> Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> wrote:
>>>
>>>>> Also, did you see my reply about having the right config? You have
>>>>> HIST_TRIGGERS undefined but yet the histogram trigger tests all pass in
>>>>> your report.
>>>>
>>>> I did see that one. Didn't get a chance to look at that yet. Do you expect
>>>> the tests to be skipped in this case? Could it be that tests aren't run?
>>>> I will look at this and let you know what I find on my test system.
>>>
>>> Your first email showed that they passed, which would be hard to do
>>> since the feature is not even enabled. ftracetest is very much set up
>>> to look at the existing pseudo files to determine if a feature exists
>>> or not, and if it does not, it returns "UNSUPPORTED". If it returned
>>> PASSED when the feature is not enabled, that would be a big time bug in
>>> the test.
>>
>> As far as I can see, what Steve you saw was my result on the 4.9 stable
>> kernel, which had been compiled with fully ftrace enabled :).
>>
>>>>
>>>>>
>>>>> One more thing, is this 100% reproducible. That is, does it always fail?
>>>>>
>>>> Failed the two times I tried.
>>
>> I've also tried to test the latest linus tree with this series with Shuah's
>> config on qemu, and could not reproduced it. (I attached the log)
>> As you can see, with Shuah's config, histogram tests are marked UNSUPPORTED.
>>
>> Of course, that is 4.12.0-rc5+ and kconfig is a bit tweaked(attached).
>> I'll try kselftest tree too.
>
> I've tried it on linux-kselftest/next, but not able to reproduce it...
>
> Thank you,

Hmm. Not sure what's happening on my test system. I will try it one more
time with a clean build and see what happens.

Thanks for debugging this.

-- Shuah