Re: trace-cmd profile is not working

[Jerome Marchand <jmarchan@redhat.com>]

On 14/05/2021 09:56, Tzvetomir Stoyanov wrote:
> Hi Jerome,
> 
> On Wed, May 12, 2021 at 5:09 PM Jerome Marchand <jmarchan@redhat.com> wrote:
>>
>> On 12/05/2021 15:55, Steven Rostedt wrote:
>>> On Wed, 12 May 2021 15:51:52 +0200
>>> Jerome Marchand <jmarchan@redhat.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> Streams, and thus trace-cmd profile, are not working. A simple
>>>> "trace-cmd profile ls" command exit with the following message
>>>> "Creating stream for 0". I've been looking at it and the issue is that
>>>> tracecmd_read_headers() tries to read the cmdlines, cpus and options
>>>> sections that have not been written to the temporary file when called
>>>> from trace_stream_init().
>>>>
>>>> AFAICT, it is caused by the two following patches:
>>>>
>>>> commit 1eea02a4 ("trace-cmd: Write saved cmdlines in the trace file at
>>>> the end of the trace.") which moved the writing of cmdlines from
>>>> create_file_fd() to tracecmd_create_file_latency() and
>>>> tracecmd_append_cpu_data()
>>>>
>>>> commit 5d4d7ec3 ("trace-cmd: Move reading of trace.dat options to
>>>> tracecmd_read_headers()") which moved the reading of options and cpu
>>>> datas to tracecmd_read_headers().
>>>>
>>>
>>> Thanks for the report. I'm not surprised, profiling and streams have not
>>> been given the love they deserve (been focusing on host/guest tracing
>>> recently).
>>>
>>> Can you fill out a bug report on bugzilla?
>>
>> Sure thing:
>> https://bugzilla.kernel.org/show_bug.cgi?id=213045
>>
>> Jerome
>>
>>>
>>>     https://bugzilla.kernel.org/buglist.cgi?component=Trace-cmd%2FKernelshark&list_id=1090417&product=Tools&resolution=---
>>>
>>> Thanks!
>>>
> 
> I've submitted a fix for this, please can you verify if it fixes the problem.
> Thanks for testing this code and reporting bugs!

Yes, it does fixes the issue have been seeing.

Thanks,
Jerome

> 
>>> -- Steve
>>>
>>
> 
>