[RFC 2/5] common/mlx5: introduce tracepoints for mlx5 drivers

[Slava Ovsiienko]

> -----Original Message-----
> From: Thomas Monjalon <thomas at monjalon.net>
> Sent: Tuesday, June 27, 2023 10:29 AM
> To: Slava Ovsiienko <viacheslavo at nvidia.com>
> Cc: dev at dpdk.org; Jerin Jacob <jerinjacobk at gmail.com>; Raslan Darawsheh
> <rasland at nvidia.com>
> Subject: Re: [RFC 2/5] common/mlx5: introduce tracepoints for mlx5 drivers
> 
> 27/06/2023 08:15, Slava Ovsiienko:
> > From: Thomas Monjalon <thomas at monjalon.net>
> > > 13/06/2023 18:01, Jerin Jacob:
> > > > On Tue, Jun 13, 2023 at 9:29 PM Slava Ovsiienko
> > > > <viacheslavo at nvidia.com>
> > > wrote:
> > > > > From: Jerin Jacob <jerinjacobk at gmail.com>
> > > > > > On Tue, Jun 13, 2023 at 9:20 PM Slava Ovsiienko
> > > > > > <viacheslavo at nvidia.com>
> > > > > > wrote:
> > > > > > >
> > > > > > > Hi,
> > > > > > >
> > > > > > > <..snip..>
> > > > > > > > >
> > > > > > > > >         mlx5_os_interrupt_handler_create; #
> WINDOWS_NO_EXPORT
> > > > > > > > >         mlx5_os_interrupt_handler_destroy; #
> > > > > > > > > WINDOWS_NO_EXPORT
> > > > > > > > > +
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_entry;
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_exit;
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_wqe;
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_wait;
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_push;
> > > > > > > > > +       __rte_pmd_mlx5_trace_tx_complete;
> > > > > > > >
> > > > > > > > No need to expose these symbols. It is getting removed
> > > > > > > > from rest of
> > > DPDK.
> > > > > > > > Application can do rte_trace_lookup() to get this address.
> > > > > > > >
> > > > > > > >
> > > > > > > It is not for application, it is for PMD itself, w/o
> > > > > > > exposing the symbols build
> > > > > > failed.
> > > > > >
> > > > > > PMD is implementing this trace endpoints, not consuming this
> > > > > > trace
> > > point.
> > > > > > Right? If so, Why to expose these symbols?
> > > > >
> > > > > As far as understand:
> > > > > The tracepoint routines are defined in dedicated
> > > > > common/mlx5_trace.c
> > > file.
> > > > > The tx_burst in mlx5 is implemented as template in header file,
> > > > > and this template is used in multiple .c files under net/mlx5 filder.
> > > > > So, common/mlx5 should expose its symbols to net/mlx5 to allow
> > > > > successful linkage.
> > > >
> > > > OK. I missed the fact the these are in common code and net driver
> > > > is depened on that.
> > > > So changes makes sense.
> > >
> > > It does not make sense to me.
> > > These are tracepoints for the ethdev driver.
> > > Why declaring them in the common library?
> >
> > Just to gather all mlx5 traces in the single file, to see all available tracing
> caps in single view.
> 
> Better to not export them.
> 
It is not about export, we have analyzing script over the trace data, and it would be better to see all the tracing
routines gathered in one place. I would prefer not to spread trace point definitions over the multiple source files.
 
With best regards,
Slava