Re: [PATCH] PCI/AER: add pcie TLP header information in the tracepoint

[Thomas Tai]

[ ... ]
> > > --- a/include/ras/ras_event.h
> > > +++ b/include/ras/ras_event.h
> > > @@ -298,30 +298,42 @@ TRACE_EVENT(non_standard_event,
> > >   TRACE_EVENT(aer_event,
> > >   	TP_PROTO(const char *dev_name,
> > >   		 const u32 status,
> > > -		 const u8 severity),
> > > +		 const u8 severity,
> > > +		 const u32 tlp_header_valid,
> > > +		 struct aer_header_log_regs *tlp),
> > >   
> > > -	TP_ARGS(dev_name, status, severity),
> > > +	TP_ARGS(dev_name, status, severity, tlp_header_valid, tlp),
> > >   
> > >   	TP_STRUCT__entry(
> > >   		__string(	dev_name,	dev_name	)
> > >   		__field(	u32,		status		)
> > >   		__field(	u8,		severity	)
> > > +		__field(	u32, 		tlp_header_valid)
>
> I'm guessing tlp_header_valid is just a boolean. It's after severity
> which is just one byte long. Why not make this one byte as well,
> otherwise you are wasting 3 bytes.

Thanks Steven. Yes boolean is fine.

> > > +		__array(	u32, 		buf, 4		)
> > >   	),
> > >   
> > >   	TP_fast_assign(
> > >   		__assign_str(dev_name, dev_name);
> > >   		__entry->status		= status;
> > >   		__entry->severity	= severity;
> > > +		__entry->tlp_header_valid = tlp_header_valid;
>
> > > +		__entry->buf[0] = tlp->dw0;
> > > +		__entry->buf[1] = tlp->dw1;
> > > +		__entry->buf[2] = tlp->dw2;
> > > +		__entry->buf[3] = tlp->dw3;
>
> Should this assignment be dependent on whether or not tlp_header_valid
> is true? Could tlp be pointing to some random memory if it isn't? What
> about:

Good catch! will do so.

> 	if ((__entry->tlp_header_valid = tlp_header_valid)) {
> 		__entry->buf[0] = tlp->dw0;
> 		__entry->buf[1] = tlp->dw1;
> 		__entry->buf[2] = tlp->dw2;
> 		__entry->buf[3] = tlp->dw3;
> 	}
>
>
> > >   	),
> > >   
> > > -	TP_printk("%s PCIe Bus Error: severity=%s, %s\n",
> > > +	TP_printk("%s PCIe Bus Error: severity=%s, %s, TLP Header=%s\n",
> > >   		__get_str(dev_name),
> > >   		__entry->severity == AER_CORRECTABLE ? "Corrected" :
> > >   			__entry->severity == AER_FATAL ?
> > >   			"Fatal" : "Uncorrected, non-fatal",
> > >   		__entry->severity == AER_CORRECTABLE ?
> > >   		__print_flags(__entry->status, "|", aer_correctable_errors) :
> > > -		__print_flags(__entry->status, "|", aer_uncorrectable_errors))
> > > +		__print_flags(__entry->status, "|", aer_uncorrectable_errors),
> > > +		__entry->tlp_header_valid ?
> > > +			__print_array(__entry->buf, 4, sizeof(unsigned int)) :
>
> Note, "sizeof" will be shown in the format file that perf and trace-cmd
> read to parse this event. They currently do not know how to parse that
> (although I could add that in the future).
>
> Since sizeof(unsigned int) is always 4 in Linux, just use 4.

Yes, I will make the aboves changes and send out V2 patch. Thank you for 
your time and comments.

Thomas

> 			__print_array(__entry->buf, 4, 4)
>
> -- Steve
>
>
> > > +			"Not available")
> > >   );
> > >   
> > >   /*
> > > --
> > > 2.14.1
> > >