Re: [net-next v7 4/4] mlx5: add support for page_pool_get_stats

[Joe Damato <jdamato@fastly.com>]

On Mon, Feb 28, 2022 at 1:17 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> Joe Damato <jdamato@fastly.com> writes:
>
> > On Sun, Feb 27, 2022 at 11:28 PM Jesper Dangaard Brouer
> > <jbrouer@redhat.com> wrote:
> >>
> >>
> >>
> >> On 25/02/2022 18.41, Joe Damato wrote:
> >> > +#ifdef CONFIG_PAGE_POOL_STATS
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_fast) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_slow) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_slow_high_order) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_empty) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_refill) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_waive) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_rec_cached) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_rec_cache_full) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_rec_ring) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_rec_ring_full) },
> >> > +     { MLX5E_DECLARE_RX_STAT(struct mlx5e_rq_stats, page_pool_rec_released_ref) },
> >> > +#endif
> >>
> >> The naming: "page_pool_rec_xxx".
> >> What does the "rec" stand for?
> >
> > rec stands for recycle.
> >
> > ethtool strings have a limited size (ETH_GSTRING_LEN - 32 bytes) and
> > the full word "recycle" didn't fit for some of the stats once the
> > queue number is prepended elsewhere in the driver code.
> >
> >> Users of ethtool -S stats... will they know "rec" is "recycle" ?
> >
> > I am open to other names or adding documentation to the driver docs to
> > explain the meaning.
>
> You could shorten the 'page_pool_' prefix to 'ppool_' or even 'pp_' and
> gain some characters that way?

I had considered this, but I thought that 'pp' was possibly as terse as 'rec'.

If you all think these are more clear, I can send a v8 of this series
that changes the strings from the above to this instead:

rx_pp_alloc_fast
rx_pp_alloc_slow
rx_pp_alloc_...

and

rx_pp_recyle_cached
rx_pp_recycle_cache_full
rx_pp_recycle_...

With this name scheme, it looks like all the stat names seem to fit. I
have no idea if this is more or less clear to the user though :)

I'll leave it up to the mlx5 maintainers; I am happy to do whatever
they prefer to get this series in.

Thanks,
Joe