Re: [PATCH v3 net-next 1/2] net: page_pool: introduce ethtool stats

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

On Mon, 11 Apr 2022 at 15:28, Lorenzo Bianconi <lorenzo@kernel.org> wrote:
>
> > Hi Lorenzo,
>
> Hi Ilias,
>
> >
> > [...]
> >
> > >
> > >         for_each_possible_cpu(cpu) {
> > >                 const struct page_pool_recycle_stats *pcpu =
> > > @@ -66,6 +87,47 @@ bool page_pool_get_stats(struct page_pool *pool,
> > >         return true;
> > >  }
> > >  EXPORT_SYMBOL(page_pool_get_stats);
> > > +
> > > +u8 *page_pool_ethtool_stats_get_strings(u8 *data)
> > > +{
> > > +       int i;
> > > +
> > > +       for (i = 0; i < ARRAY_SIZE(pp_stats); i++) {
> > > +               memcpy(data, pp_stats[i], ETH_GSTRING_LEN);
> > > +               data += ETH_GSTRING_LEN;
> > > +       }
> > > +
> > > +       return data;
> >
> > Is there a point returning data here or can we make this a void?
>
> it is to add the capability to add more strings in the driver code after
> running page_pool_ethtool_stats_get_strings.

But the current driver isn't using it.  I don't have too much
experience with how drivers consume ethtool stats, but would it make
more sense to return a length instead of a pointer? Maybe Andrew has
an idea.

Thanks
/Ilias
>
> >
> > > +}
> > > +EXPORT_SYMBOL(page_pool_ethtool_stats_get_strings);
> > > +
> > > +int page_pool_ethtool_stats_get_count(void)
> > > +{
> > > +       return ARRAY_SIZE(pp_stats);
> > > +}
> > > +EXPORT_SYMBOL(page_pool_ethtool_stats_get_count);
> > > +
> > > +u64 *page_pool_ethtool_stats_get(u64 *data, struct page_pool_stats *stats)
> > > +{
> > > +       int i;
> > > +
> > > +       for (i = 0; i < ARRAY_SIZE(pp_stats); i++) {
> > > +               *data++ = stats->alloc_stats.fast;
> > > +               *data++ = stats->alloc_stats.slow;
> > > +               *data++ = stats->alloc_stats.slow_high_order;
> > > +               *data++ = stats->alloc_stats.empty;
> > > +               *data++ = stats->alloc_stats.refill;
> > > +               *data++ = stats->alloc_stats.waive;
> > > +               *data++ = stats->recycle_stats.cached;
> > > +               *data++ = stats->recycle_stats.cache_full;
> > > +               *data++ = stats->recycle_stats.ring;
> > > +               *data++ = stats->recycle_stats.ring_full;
> > > +               *data++ = stats->recycle_stats.released_refcnt;
> > > +       }
> > > +
> > > +       return data;
> >
> > Ditto
>
> same here.
>
> Regards,
> Lorenzo
>
> >
> > > +}
> > > +EXPORT_SYMBOL(page_pool_ethtool_stats_get);
> > >  #else
> > >  #define alloc_stat_inc(pool, __stat)
> > >  #define recycle_stat_inc(pool, __stat)
> > > --
> > > 2.35.1
> > >
> >
> > Thanks
> > /Ilias