On Tue, Aug 26, 2025 at 5:50 AM Eric Dumazet [off-list ref] wrote:

When a packet flood hits one or more RAW sockets, many cpus
have to update sk->sk_drops.

This slows down other cpus, because currently
sk_drops is in sock_write_rx group.

Add a socket_drop_counters structure to raw sockets.

Using dedicated cache lines to hold drop counters
makes sure that consumers no longer suffer from
false sharing if/when producers only change sk->sk_drops.

This adds 128 bytes per RAW socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>

Thank you, Eric !