On 07/03/2019 02:52 PM, Eelco Chaudron wrote:
> When an AF_XDP application received X packets, it does not mean X
> frames can be stuffed into the producer ring. To make it easier for
> AF_XDP applications this API allows them to check how many frames can
> be added into the ring.
>
> Signed-off-by: Eelco Chaudron <echau...@redhat.com>
The commit log as it is along with the code is a bit too confusing for
readers. After all you only do a rename below. It would need to additionally
state that the rename is as per libbpf convention (xyz__ prefix) in order to
denote that this API is exposed to be used by applications.
Given you are doing this for xsk_prod_nb_free(), should we do the same for
xsk_cons_nb_avail() as well? Extending XDP sample app would be reasonable
addition as well in this context.
> ---
>
> v2 -> v3
> - Removed cache by pass option
>
> v1 -> v2
> - Renamed xsk_ring_prod__free() to xsk_ring_prod__nb_free()
> - Add caching so it will only touch global state when needed
>
> tools/lib/bpf/xsk.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
> index 82ea71a0f3ec..3411556e04d9 100644
> --- a/tools/lib/bpf/xsk.h
> +++ b/tools/lib/bpf/xsk.h
> @@ -76,7 +76,7 @@ xsk_ring_cons__rx_desc(const struct xsk_ring_cons *rx,
> __u32 idx)
> return &descs[idx & rx->mask];
> }
>
> -static inline __u32 xsk_prod_nb_free(struct xsk_ring_prod *r, __u32 nb)
> +static inline __u32 xsk_prod__nb_free(struct xsk_ring_prod *r, __u32 nb)
> {
> __u32 free_entries = r->cached_cons - r->cached_prod;
>
> @@ -110,7 +110,7 @@ static inline __u32 xsk_cons_nb_avail(struct
> xsk_ring_cons *r, __u32 nb)
> static inline size_t xsk_ring_prod__reserve(struct xsk_ring_prod *prod,
> size_t nb, __u32 *idx)
> {
> - if (xsk_prod_nb_free(prod, nb) < nb)
> + if (xsk_prod__nb_free(prod, nb) < nb)
> return 0;
>
> *idx = prod->cached_prod;
>
