RE: [PATCH v1 3/3] scsi: ufs: Make UPIU trace easier differentiate among CDB, OSF, and TM

[Avri Altman]

> 
> On Mon, 7 Dec 2020 07:57:27 +0000
> Avri Altman <Avri.Altman@xxxxxxx> wrote:
> 
> > >
> > >         TP_printk(
> > > -               "%s: %s: HDR:%s, CDB:%s",
> > > +               "%s: %s: HDR:%s, %s:%s",
> > >                 __get_str(str), __get_str(dev_name),
> > >                 __print_hex(__entry->hdr, sizeof(__entry->hdr)),
> > > +               __get_str(tsf_type),
> > This breaks what current parsers expects.
> > Why str is not enough to distinguish between the command?
> 
> Hopefully it shouldn't. Reading from user space should use the
> libtraceevent library, that reads the format files and extracts the raw
> data to find the fields. As long as the field exists, it should not break
> user space parsers. If it does, please let me know, and I'll gladly help
> change the user space code to use libtraceevent :-)
Hi Steve,
Thanks. I wasn't aware of libtraceevent - is this a new thing?

We have a relatively sophisticated analysis platform that utilizes raw traces,
Among which the upiu trace is the most important and informative.

This tool has evolved over the years, adding more and more parsers per need,
and the users are picking the appropriate parser per the trace they used.

We will surely be glad to adopt new tracing capabilities,
But we would prefer not to break anything.

Thanks,
Avri