diff options
| -rw-r--r-- | include/linux/tcp.h | 7 | ||||
| -rw-r--r-- | include/net/tcp.h | 14 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 30 |
3 files changed, 49 insertions, 2 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 32a7c7e35b71..d5d3bd814338 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -211,8 +211,11 @@ struct tcp_sock { u8 reord; /* reordering detected */ } rack; u16 advmss; /* Advertised MSS */ - u8 rate_app_limited:1, /* rate_{delivered,interval_us} limited? */ - unused:7; + u32 chrono_start; /* Start time in jiffies of a TCP chrono */ + u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */ + u8 chrono_type:2, /* current chronograph type */ + rate_app_limited:1, /* rate_{delivered,interval_us} limited? */ + unused:5; u8 nonagle : 4,/* Disable Nagle algorithm? */ thin_lto : 1,/* Use linear timeouts for thin streams */ thin_dupack : 1,/* Fast retransmit on first dupack */ diff --git a/include/net/tcp.h b/include/net/tcp.h index 7de80739adab..e5ff4083870d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1516,6 +1516,20 @@ struct tcp_fastopen_context { struct rcu_head rcu; }; +/* Latencies incurred by various limits for a sender. They are + * chronograph-like stats that are mutually exclusive. + */ +enum tcp_chrono { + TCP_CHRONO_UNSPEC, + TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ + TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ + TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ + __TCP_CHRONO_MAX, +}; + +void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); +void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); + /* write queue abstraction */ static inline void tcp_write_queue_purge(struct sock *sk) { diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 19105b46a304..34f751776a01 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2081,6 +2081,36 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb, return false; } +static void tcp_chrono_set(struct tcp_sock *tp, const enum tcp_chrono new) +{ + const u32 now = tcp_time_stamp; + + if (tp->chrono_type > TCP_CHRONO_UNSPEC) + tp->chrono_stat[tp->chrono_type - 1] += now - tp->chrono_start; + tp->chrono_start = now; + tp->chrono_type = new; +} + +void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type) +{ + struct tcp_sock *tp = tcp_sk(sk); + + /* If there are multiple conditions worthy of tracking in a + * chronograph then the highest priority enum takes precedence over + * the other conditions. So that if something "more interesting" + * starts happening, stop the previous chrono and start a new one. + */ + if (type > tp->chrono_type) + tcp_chrono_set(tp, type); +} + +void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type) +{ + struct tcp_sock *tp = tcp_sk(sk); + + tcp_chrono_set(tp, TCP_CHRONO_UNSPEC); +} + /* This routine writes packets to the network. It advances the * send_head. This happens as incoming acks open up the remote * window for us. |