AW: GSoC Project | Basic Support for Trace Compass

[Jan.Sommer at dlr.de]

Hi Ravindra,

> -----Ursprüngliche Nachricht-----
> Von: devel [mailto:devel-bounces at rtems.org] Im Auftrag von Ravindra
> Kumar Meena
> Gesendet: Dienstag, 25. Juni 2019 14:39
> An: Sebastian Huber
> Cc: devel
> Betreff: Re: GSoC Project | Basic Support for Trace Compass
> 
> Hi Sebastian,
> 
> Like I said that all values are correct(ns, CPU, data) except
> rtems_record_event. This is happening because of byte order issue.
> 
> This is the warning output of babeltrace
> 
> [warning] Unknown value 927712935936 in enum.
> 0 RTEMS_RECORDING_EVENT: { ns = 4281426372217274368, cpu = 0,
> events = ( <unknown> : container = 927712935936 ), data = 167837702 }
> [warning] Unknown value 897648164864 in enum.
> 0 RTEMS_RECORDING_EVENT: { ns = 4281426372217274368, cpu = 0,
> events = ( <unknown> : container = 897648164864 ), data = 32440 }
> 
> Whatever value is passed on "ctf_item.data=item->event;" is converted
> into big-endian value. That's why it giving huge value e.g 897648164864.
> See the above output.
> 
I have only had a look at the specification, but according to https://diamon.org/ctf/#spec4.1.3 you can set the global "byte_order" of  your stream in the trace description of your metadata file and override this default behavior for certain types.
In the metadata file of your repository (https://github.com/rmeena840/rtems-tools/blob/ravindra-rtems/misc/ctf/metadata) you set trace to:
trace {
    major = 1;
    minor = 8;
    byte_order = le;
}; 

Which defaults to little-endian and as far as I see you never overwrite it for your event fields.

> If we change the byte order of 897648164864 then it will be 215 which is in
> the range of 0 to 1023. This is what we want.
> 
> If we could pass the big-endian value on "ctf_item.data=item->event;" then
> it will work fine. I intentionally tried to pass 897648164864 directly to
> "ctf_item.data=item->event;" and it was working fine because its byte
> order is changed and its new value will be 215.
> 
> I tried a few approaches but didn't work for me. Any idea how to deal with
> it?
> 
> Thanks
> 
> 
> 
> --
> 
> Ravindra Kumar Meena,
> B. Tech. Computer Science and Engineering,
> 
> Indian Institute of Technology (Indian School of Mines)
> <https://www.iitism.ac.in/> , Dhanbad