Jordan Rife wrote:
> Replace the offset-based approach for tracking progress through a bucket
> in the UDP table with one based on unique, monotonically increasing
> index numbers associated with each socket in a bucket.
>
> Signed-off-by: Jordan Rife <jrife@xxxxxxxxxx>
> ---
> include/net/sock.h | 2 ++
> include/net/udp.h | 1 +
> net/ipv4/udp.c | 38 +++++++++++++++++++++++++-------------
> 3 files changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 8036b3b79cd8..b11f43e8e7ec 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -228,6 +228,7 @@ struct sock_common {
> u32 skc_window_clamp;
> u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
> };
> + __s64 skc_idx;
> /* public: */
> };
>
> @@ -378,6 +379,7 @@ struct sock {
> #define sk_incoming_cpu __sk_common.skc_incoming_cpu
> #define sk_flags __sk_common.skc_flags
> #define sk_rxhash __sk_common.skc_rxhash
> +#define sk_idx __sk_common.skc_idx
>
> __cacheline_group_begin(sock_write_rx);
>
> diff --git a/include/net/udp.h b/include/net/udp.h
> index 6e89520e100d..9398561addc6 100644
> --- a/include/net/udp.h
> +++ b/include/net/udp.h
> @@ -102,6 +102,7 @@ struct udp_table {
> #endif
> unsigned int mask;
> unsigned int log;
> + atomic64_t ver;
> };
> extern struct udp_table udp_table;
> void udp_table_init(struct udp_table *, const char *);
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index a9bb9ce5438e..d7e9b3346983 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -229,6 +229,11 @@ static int udp_reuseport_add_sock(struct sock *sk, struct udp_hslot *hslot)
> return reuseport_alloc(sk, inet_rcv_saddr_any(sk));
> }
>
> +static inline __s64 udp_table_next_idx(struct udp_table *udptable, bool pos)
> +{
> + return (pos ? 1 : -1) * atomic64_inc_return(&udptable->ver);
> +}
Can this BPF feature be fixed without adding extra complexity and cost
to the normal protocol paths?
