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Diffstat (limited to 'include/linux/tcp.h')
-rw-r--r--include/linux/tcp.h248
1 files changed, 134 insertions, 114 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index b646b574b060..89b290d8c8dc 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -190,23 +190,121 @@ static inline bool tcp_rsk_used_ao(const struct request_sock *req)
#define TCP_RMEM_TO_WIN_SCALE 8
struct tcp_sock {
+ /* Cacheline organization can be found documented in
+ * Documentation/networking/net_cachelines/tcp_sock.rst.
+ * Please update the document when adding new fields.
+ */
+
/* inet_connection_sock has to be the first member of tcp_sock */
struct inet_connection_sock inet_conn;
- u16 tcp_header_len; /* Bytes of tcp header to send */
+
+ /* TX read-mostly hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_read_tx);
+ /* timestamp of last sent data packet (for restart window) */
+ u32 max_window; /* Maximal window ever seen from peer */
+ u32 rcv_ssthresh; /* Current window clamp */
+ u32 reordering; /* Packet reordering metric. */
+ u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */
u16 gso_segs; /* Max number of segs per GSO packet */
+ /* from STCP, retrans queue hinting */
+ struct sk_buff *lost_skb_hint;
+ struct sk_buff *retransmit_skb_hint;
+ __cacheline_group_end(tcp_sock_read_tx);
+
+ /* TXRX read-mostly hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_read_txrx);
+ u32 tsoffset; /* timestamp offset */
+ u32 snd_wnd; /* The window we expect to receive */
+ u32 mss_cache; /* Cached effective mss, not including SACKS */
+ u32 snd_cwnd; /* Sending congestion window */
+ u32 prr_out; /* Total number of pkts sent during Recovery. */
+ u32 lost_out; /* Lost packets */
+ u32 sacked_out; /* SACK'd packets */
+ u16 tcp_header_len; /* Bytes of tcp header to send */
+ u8 chrono_type : 2, /* current chronograph type */
+ repair : 1,
+ is_sack_reneg:1, /* in recovery from loss with SACK reneg? */
+ is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
+ __cacheline_group_end(tcp_sock_read_txrx);
+
+ /* RX read-mostly hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_read_rx);
+ u32 copied_seq; /* Head of yet unread data */
+ u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
+ u32 snd_wl1; /* Sequence for window update */
+ u32 tlp_high_seq; /* snd_nxt at the time of TLP */
+ u32 rttvar_us; /* smoothed mdev_max */
+ u32 retrans_out; /* Retransmitted packets out */
+ u16 advmss; /* Advertised MSS */
+ u16 urg_data; /* Saved octet of OOB data and control flags */
+ u32 lost; /* Total data packets lost incl. rexmits */
+ struct minmax rtt_min;
+ /* OOO segments go in this rbtree. Socket lock must be held. */
+ struct rb_root out_of_order_queue;
+ u32 snd_ssthresh; /* Slow start size threshold */
+ __cacheline_group_end(tcp_sock_read_rx);
+ /* TX read-write hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_write_tx) ____cacheline_aligned;
+ u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
+ * The total number of segments sent.
+ */
+ u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
+ * total number of data segments sent.
+ */
+ u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut
+ * total number of data bytes sent.
+ */
+ u32 snd_sml; /* Last byte of the most recently transmitted small packet */
+ u32 chrono_start; /* Start time in jiffies of a TCP chrono */
+ u32 chrono_stat[3]; /* Time in jiffies for chrono_stat stats */
+ u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
+ u32 pushed_seq; /* Last pushed seq, required to talk to windows */
+ u32 lsndtime;
+ u32 mdev_us; /* medium deviation */
+ u64 tcp_wstamp_ns; /* departure time for next sent data packet */
+ u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */
+ u64 tcp_mstamp; /* most recent packet received/sent */
+ u32 rtt_seq; /* sequence number to update rttvar */
+ struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
+ struct sk_buff *highest_sack; /* skb just after the highest
+ * skb with SACKed bit set
+ * (validity guaranteed only if
+ * sacked_out > 0)
+ */
+ u8 ecn_flags; /* ECN status bits. */
+ __cacheline_group_end(tcp_sock_write_tx);
+
+ /* TXRX read-write hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_write_txrx);
/*
* Header prediction flags
* 0x5?10 << 16 + snd_wnd in net byte order
*/
__be32 pred_flags;
-
+ u32 rcv_nxt; /* What we want to receive next */
+ u32 snd_nxt; /* Next sequence we send */
+ u32 snd_una; /* First byte we want an ack for */
+ u32 window_clamp; /* Maximal window to advertise */
+ u32 srtt_us; /* smoothed round trip time << 3 in usecs */
+ u32 packets_out; /* Packets which are "in flight" */
+ u32 snd_up; /* Urgent pointer */
+ u32 delivered; /* Total data packets delivered incl. rexmits */
+ u32 delivered_ce; /* Like the above but only ECE marked packets */
+ u32 app_limited; /* limited until "delivered" reaches this val */
+ u32 rcv_wnd; /* Current receiver window */
/*
- * RFC793 variables by their proper names. This means you can
- * read the code and the spec side by side (and laugh ...)
- * See RFC793 and RFC1122. The RFC writes these in capitals.
+ * Options received (usually on last packet, some only on SYN packets).
*/
- u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived
+ struct tcp_options_received rx_opt;
+ u8 nonagle : 4,/* Disable Nagle algorithm? */
+ rate_app_limited:1; /* rate_{delivered,interval_us} limited? */
+ __cacheline_group_end(tcp_sock_write_txrx);
+
+ /* RX read-write hotpath cache lines */
+ __cacheline_group_begin(tcp_sock_write_rx);
+ u64 bytes_received;
+ /* RFC4898 tcpEStatsAppHCThruOctetsReceived
* sum(delta(rcv_nxt)), or how many bytes
* were acked.
*/
@@ -216,45 +314,44 @@ struct tcp_sock {
u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn
* total number of data segments in.
*/
- u32 rcv_nxt; /* What we want to receive next */
- u32 copied_seq; /* Head of yet unread data */
u32 rcv_wup; /* rcv_nxt on last window update sent */
- u32 snd_nxt; /* Next sequence we send */
- u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
- * The total number of segments sent.
- */
- u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
- * total number of data segments sent.
- */
- u64 bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut
- * total number of data bytes sent.
- */
+ u32 max_packets_out; /* max packets_out in last window */
+ u32 cwnd_usage_seq; /* right edge of cwnd usage tracking flight */
+ u32 rate_delivered; /* saved rate sample: packets delivered */
+ u32 rate_interval_us; /* saved rate sample: time elapsed */
+ u32 rcv_rtt_last_tsecr;
+ u64 first_tx_mstamp; /* start of window send phase */
+ u64 delivered_mstamp; /* time we reached "delivered" */
u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
* sum(delta(snd_una)), or how many bytes
* were acked.
*/
+ struct {
+ u32 rtt_us;
+ u32 seq;
+ u64 time;
+ } rcv_rtt_est;
+/* Receiver queue space */
+ struct {
+ u32 space;
+ u32 seq;
+ u64 time;
+ } rcvq_space;
+ __cacheline_group_end(tcp_sock_write_rx);
+ /* End of Hot Path */
+
+/*
+ * RFC793 variables by their proper names. This means you can
+ * read the code and the spec side by side (and laugh ...)
+ * See RFC793 and RFC1122. The RFC writes these in capitals.
+ */
u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
* total number of DSACK blocks received
*/
- u32 snd_una; /* First byte we want an ack for */
- u32 snd_sml; /* Last byte of the most recently transmitted small packet */
- u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
- u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
u32 last_oow_ack_time; /* timestamp of last out-of-window ACK */
u32 compressed_ack_rcv_nxt;
-
- u32 tsoffset; /* timestamp offset */
-
struct list_head tsq_node; /* anchor in tsq_tasklet.head list */
- struct list_head tsorted_sent_queue; /* time-sorted sent but un-SACKed skbs */
-
- u32 snd_wl1; /* Sequence for window update */
- u32 snd_wnd; /* The window we expect to receive */
- u32 max_window; /* Maximal window ever seen from peer */
- u32 mss_cache; /* Cached effective mss, not including SACKS */
- u32 window_clamp; /* Maximal window to advertise */
- u32 rcv_ssthresh; /* Current window clamp */
u8 scaling_ratio; /* see tcp_win_from_space() */
/* Information of the most recently (s)acked skb */
struct tcp_rack {
@@ -268,24 +365,16 @@ struct tcp_sock {
dsack_seen:1, /* Whether DSACK seen after last adj */
advanced:1; /* mstamp advanced since last lost marking */
} rack;
- u16 advmss; /* Advertised MSS */
u8 compressed_ack;
u8 dup_ack_counter:2,
tlp_retrans:1, /* TLP is a retransmission */
tcp_usec_ts:1, /* TSval values in usec */
unused:4;
- 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? */
+ u8 thin_lto : 1,/* Use linear timeouts for thin streams */
+ recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */
fastopen_connect:1, /* FASTOPEN_CONNECT sockopt */
fastopen_no_cookie:1, /* Allow send/recv SYN+data without a cookie */
- is_sack_reneg:1, /* in recovery from loss with SACK reneg? */
- fastopen_client_fail:2; /* reason why fastopen failed */
- u8 nonagle : 4,/* Disable Nagle algorithm? */
- thin_lto : 1,/* Use linear timeouts for thin streams */
- recvmsg_inq : 1,/* Indicate # of bytes in queue upon recvmsg */
- repair : 1,
+ fastopen_client_fail:2, /* reason why fastopen failed */
frto : 1;/* F-RTO (RFC5682) activated in CA_Loss */
u8 repair_queue;
u8 save_syn:2, /* Save headers of SYN packet */
@@ -293,45 +382,19 @@ struct tcp_sock {
syn_fastopen:1, /* SYN includes Fast Open option */
syn_fastopen_exp:1,/* SYN includes Fast Open exp. option */
syn_fastopen_ch:1, /* Active TFO re-enabling probe */
- syn_data_acked:1,/* data in SYN is acked by SYN-ACK */
- is_cwnd_limited:1;/* forward progress limited by snd_cwnd? */
- u32 tlp_high_seq; /* snd_nxt at the time of TLP */
+ syn_data_acked:1;/* data in SYN is acked by SYN-ACK */
u32 tcp_tx_delay; /* delay (in usec) added to TX packets */
- u64 tcp_wstamp_ns; /* departure time for next sent data packet */
- u64 tcp_clock_cache; /* cache last tcp_clock_ns() (see tcp_mstamp_refresh()) */
/* RTT measurement */
- u64 tcp_mstamp; /* most recent packet received/sent */
- u32 srtt_us; /* smoothed round trip time << 3 in usecs */
- u32 mdev_us; /* medium deviation */
u32 mdev_max_us; /* maximal mdev for the last rtt period */
- u32 rttvar_us; /* smoothed mdev_max */
- u32 rtt_seq; /* sequence number to update rttvar */
- struct minmax rtt_min;
- u32 packets_out; /* Packets which are "in flight" */
- u32 retrans_out; /* Retransmitted packets out */
- u32 max_packets_out; /* max packets_out in last window */
- u32 cwnd_usage_seq; /* right edge of cwnd usage tracking flight */
-
- u16 urg_data; /* Saved octet of OOB data and control flags */
- u8 ecn_flags; /* ECN status bits. */
u8 keepalive_probes; /* num of allowed keep alive probes */
- u32 reordering; /* Packet reordering metric. */
u32 reord_seen; /* number of data packet reordering events */
- u32 snd_up; /* Urgent pointer */
-
-/*
- * Options received (usually on last packet, some only on SYN packets).
- */
- struct tcp_options_received rx_opt;
/*
* Slow start and congestion control (see also Nagle, and Karn & Partridge)
*/
- u32 snd_ssthresh; /* Slow start size threshold */
- u32 snd_cwnd; /* Sending congestion window */
u32 snd_cwnd_cnt; /* Linear increase counter */
u32 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
u32 snd_cwnd_used;
@@ -339,32 +402,10 @@ struct tcp_sock {
u32 prior_cwnd; /* cwnd right before starting loss recovery */
u32 prr_delivered; /* Number of newly delivered packets to
* receiver in Recovery. */
- u32 prr_out; /* Total number of pkts sent during Recovery. */
- u32 delivered; /* Total data packets delivered incl. rexmits */
- u32 delivered_ce; /* Like the above but only ECE marked packets */
- u32 lost; /* Total data packets lost incl. rexmits */
- u32 app_limited; /* limited until "delivered" reaches this val */
- u64 first_tx_mstamp; /* start of window send phase */
- u64 delivered_mstamp; /* time we reached "delivered" */
- u32 rate_delivered; /* saved rate sample: packets delivered */
- u32 rate_interval_us; /* saved rate sample: time elapsed */
-
- u32 rcv_wnd; /* Current receiver window */
- u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
- u32 notsent_lowat; /* TCP_NOTSENT_LOWAT */
- u32 pushed_seq; /* Last pushed seq, required to talk to windows */
- u32 lost_out; /* Lost packets */
- u32 sacked_out; /* SACK'd packets */
struct hrtimer pacing_timer;
struct hrtimer compressed_ack_timer;
- /* from STCP, retrans queue hinting */
- struct sk_buff* lost_skb_hint;
- struct sk_buff *retransmit_skb_hint;
-
- /* OOO segments go in this rbtree. Socket lock must be held. */
- struct rb_root out_of_order_queue;
struct sk_buff *ooo_last_skb; /* cache rb_last(out_of_order_queue) */
/* SACKs data, these 2 need to be together (see tcp_options_write) */
@@ -373,12 +414,6 @@ struct tcp_sock {
struct tcp_sack_block recv_sack_cache[4];
- struct sk_buff *highest_sack; /* skb just after the highest
- * skb with SACKed bit set
- * (validity guaranteed only if
- * sacked_out > 0)
- */
-
int lost_cnt_hint;
u32 prior_ssthresh; /* ssthresh saved at recovery start */
@@ -429,21 +464,6 @@ struct tcp_sock {
u32 rcv_ooopack; /* Received out-of-order packets, for tcpinfo */
-/* Receiver side RTT estimation */
- u32 rcv_rtt_last_tsecr;
- struct {
- u32 rtt_us;
- u32 seq;
- u64 time;
- } rcv_rtt_est;
-
-/* Receiver queue space */
- struct {
- u32 space;
- u32 seq;
- u64 time;
- } rcvq_space;
-
/* TCP-specific MTU probe information. */
struct {
u32 probe_seq_start;