From: Eric Dumazet <eduma...@google.com>
Group all the often used fields in the first cache line,
to reduce cache line misses.
Signed-off-by: Eric Dumazet <eduma...@google.com>
---
include/net/tcp.h | 42 +++++++++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 15 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index
075de26f449d27093ec6eeb114d7f53c328b2136..b34b2daf98d90930a7456f147d04e5b936185cbc
100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1035,44 +1035,56 @@ struct rate_sample {
};
struct tcp_congestion_ops {
- struct list_head list;
- u32 key;
- u32 flags;
-
- /* initialize private data (optional) */
- void (*init)(struct sock *sk);
- /* cleanup private data (optional) */
- void (*release)(struct sock *sk);
+/* fast path fields are put first to fill one cache line */
/* return slow start threshold (required) */
u32 (*ssthresh)(struct sock *sk);
+
/* do new cwnd calculation (required) */
void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked);
+
/* call before changing ca_state (optional) */
void (*set_state)(struct sock *sk, u8 new_state);
+
/* call when cwnd event occurs (optional) */
void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
+
/* call when ack arrives (optional) */
void (*in_ack_event)(struct sock *sk, u32 flags);
- /* new value of cwnd after loss (required) */
- u32 (*undo_cwnd)(struct sock *sk);
+
/* hook for packet ack accounting (optional) */
void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample);
+
/* override sysctl_tcp_min_tso_segs */
u32 (*min_tso_segs)(struct sock *sk);
- /* returns the multiplier used in tcp_sndbuf_expand (optional) */
- u32 (*sndbuf_expand)(struct sock *sk);
+
/* call when packets are delivered to update cwnd and pacing rate,
* after all the ca_state processing. (optional)
*/
void (*cong_control)(struct sock *sk, const struct rate_sample *rs);
+
+
+ /* new value of cwnd after loss (required) */
+ u32 (*undo_cwnd)(struct sock *sk);
+ /* returns the multiplier used in tcp_sndbuf_expand (optional) */
+ u32 (*sndbuf_expand)(struct sock *sk);
+
+/* control/slow paths put last */
/* get info for inet_diag (optional) */
size_t (*get_info)(struct sock *sk, u32 ext, int *attr,
union tcp_cc_info *info);
- char name[TCP_CA_NAME_MAX];
- struct module *owner;
-};
+ char name[TCP_CA_NAME_MAX];
+ struct module *owner;
+ struct list_head list;
+ u32 key;
+ u32 flags;
+
+ /* initialize private data (optional) */
+ void (*init)(struct sock *sk);
+ /* cleanup private data (optional) */
+ void (*release)(struct sock *sk);
+} ____cacheline_aligned_in_smp;
int tcp_register_congestion_control(struct tcp_congestion_ops *type);
void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
--
2.31.0.208.g409f899ff0-goog
