Current File : //usr/include/netinet/tcp_stacks/tcp_rack.h
/*-
* Copyright (c) 2016-2020 Netflix, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NETINET_TCP_RACK_H_
#define _NETINET_TCP_RACK_H_
#define RACK_ACKED 0x0001/* The remote endpoint acked this */
#define RACK_TO_MIXED 0x0002/* A timeout occured that mixed the send order - not used */
#define RACK_DEFERRED 0x0004/* We can't use this for RTT calc - not used */
#define RACK_OVERMAX 0x0008/* We have more retran's then we can fit */
#define RACK_SACK_PASSED 0x0010/* A sack was done above this block */
#define RACK_WAS_SACKPASS 0x0020/* We retransmitted due to SACK pass */
#define RACK_HAS_FIN 0x0040/* segment is sent with fin */
#define RACK_TLP 0x0080/* segment sent as tail-loss-probe */
#define RACK_RWND_COLLAPSED 0x0100/* The peer collapsed the rwnd on the segment */
#define RACK_APP_LIMITED 0x0200/* We went app limited after this send */
#define RACK_WAS_ACKED 0x0400/* a RTO undid the ack, but it already had a rtt calc done */
#define RACK_HAS_SIN 0x0800/* SIN is on this guy */
#define RACK_NUM_OF_RETRANS 3
#define RACK_INITIAL_RTO 1000 /* 1 second in milli seconds */
#define RACK_REQ_AVG 4 /* Must be less than 256 */
struct rack_sendmap {
uint32_t r_start; /* Sequence number of the segment */
uint32_t r_end; /* End seq, this is 1 beyond actually */
TAILQ_ENTRY(rack_sendmap) r_tnext; /* Time of transmit based next */
RB_ENTRY(rack_sendmap) r_next; /* RB Tree next */
uint32_t r_rtr_bytes; /* How many bytes have been retransmitted */
uint16_t r_rtr_cnt; /* Retran count, index this -1 to get time
* sent */
uint16_t r_flags; /* Flags as defined above */
uint32_t r_tim_lastsent[RACK_NUM_OF_RETRANS];
uint32_t usec_orig_send; /* time of orginal send in useconds */
uint32_t r_nseq_appl; /* If this one is app limited, this is the nxt seq limited */
uint32_t r_ack_arrival; /* This is the time of ack-arrival (if SACK'd) */
uint8_t r_dupack; /* Dup ack count */
uint8_t r_in_tmap; /* Flag to see if its in the r_tnext array */
uint8_t r_limit_type; /* is this entry counted against a limit? */
uint8_t r_just_ret : 1, /* After sending, the next pkt was just returned, i.e. limited */
r_one_out_nr : 1, /* Special case 1 outstanding and not in recovery */
r_avail : 6;
uint8_t r_resv[36];
};
RB_HEAD(rack_rb_tree_head, rack_sendmap);
TAILQ_HEAD(rack_head, rack_sendmap);
#define RACK_LIMIT_TYPE_SPLIT 1
/*
* We use the rate sample structure to
* assist in single sack/ack rate and rtt
* calculation. In the future we will expand
* this in BBR to do forward rate sample
* b/w estimation.
*/
#define RACK_RTT_EMPTY 0x00000001 /* Nothing yet stored in RTT's */
#define RACK_RTT_VALID 0x00000002 /* We have at least one valid RTT */
struct rack_rtt_sample {
uint32_t rs_flags;
uint32_t rs_rtt_lowest;
uint32_t rs_rtt_highest;
uint32_t rs_rtt_cnt;
uint32_t rs_us_rtt;
int32_t confidence;
uint64_t rs_rtt_tot;
uint16_t rs_us_rtrcnt;
};
#define RACK_LOG_TYPE_ACK 0x01
#define RACK_LOG_TYPE_OUT 0x02
#define RACK_LOG_TYPE_TO 0x03
#define RACK_LOG_TYPE_ALLOC 0x04
#define RACK_LOG_TYPE_FREE 0x05
struct rack_log {
union {
struct rack_sendmap *rsm; /* For alloc/free */
uint64_t sb_acc;/* For out/ack or t-o */
};
uint32_t th_seq;
uint32_t th_ack;
uint32_t snd_una;
uint32_t snd_nxt; /* th_win for TYPE_ACK */
uint32_t snd_max;
uint32_t blk_start[4];
uint32_t blk_end[4];
uint8_t type;
uint8_t n_sackblks;
uint16_t len; /* Timeout T3=1, TLP=2, RACK=3 */
};
/*
* Magic numbers for logging timeout events if the
* logging is enabled.
*/
#define RACK_TO_FRM_TMR 1
#define RACK_TO_FRM_TLP 2
#define RACK_TO_FRM_RACK 3
#define RACK_TO_FRM_KEEP 4
#define RACK_TO_FRM_PERSIST 5
#define RACK_TO_FRM_DELACK 6
struct rack_opts_stats {
uint64_t tcp_rack_prop_rate;
uint64_t tcp_rack_prop;
uint64_t tcp_rack_tlp_reduce;
uint64_t tcp_rack_early_recov;
uint64_t tcp_rack_pace_always;
uint64_t tcp_rack_pace_reduce;
uint64_t tcp_rack_max_seg;
uint64_t tcp_rack_prr_sendalot;
uint64_t tcp_rack_min_to;
uint64_t tcp_rack_early_seg;
uint64_t tcp_rack_reord_thresh;
uint64_t tcp_rack_reord_fade;
uint64_t tcp_rack_tlp_thresh;
uint64_t tcp_rack_pkt_delay;
uint64_t tcp_rack_tlp_inc_var;
uint64_t tcp_tlp_use;
uint64_t tcp_rack_idle_reduce;
uint64_t tcp_rack_idle_reduce_high;
uint64_t rack_no_timer_in_hpts;
uint64_t tcp_rack_min_pace_seg;
uint64_t tcp_rack_pace_rate_ca;
uint64_t tcp_rack_rr;
uint64_t tcp_rack_do_detection;
uint64_t tcp_rack_rrr_no_conf_rate;
uint64_t tcp_initial_rate;
uint64_t tcp_initial_win;
uint64_t tcp_hdwr_pacing;
uint64_t tcp_gp_inc_ss;
uint64_t tcp_gp_inc_ca;
uint64_t tcp_gp_inc_rec;
uint64_t tcp_rack_force_max_seg;
uint64_t tcp_rack_pace_rate_ss;
uint64_t tcp_rack_pace_rate_rec;
/* Temp counters for dsack */
uint64_t tcp_sack_path_1;
uint64_t tcp_sack_path_2a;
uint64_t tcp_sack_path_2b;
uint64_t tcp_sack_path_3;
uint64_t tcp_sack_path_4;
/* non temp counters */
uint64_t tcp_rack_scwnd;
uint64_t tcp_rack_noprr;
uint64_t tcp_rack_cfg_rate;
uint64_t tcp_timely_dyn;
uint64_t tcp_rack_mbufq;
uint64_t tcp_fillcw;
uint64_t tcp_npush;
uint64_t tcp_lscwnd;
uint64_t tcp_profile;
};
/* RTT shrink reasons */
#define RACK_RTTS_INIT 0
#define RACK_RTTS_NEWRTT 1
#define RACK_RTTS_EXITPROBE 2
#define RACK_RTTS_ENTERPROBE 3
#define RACK_RTTS_REACHTARGET 4
#define RACK_RTTS_SEEHBP 5
#define RACK_RTTS_NOBACKOFF 6
#define RACK_RTTS_SAFETY 7
#define RACK_USE_BEG 1
#define RACK_USE_END 2
#define RACK_USE_END_OR_THACK 3
#define TLP_USE_ID 1 /* Internet draft behavior */
#define TLP_USE_TWO_ONE 2 /* Use 2.1 behavior */
#define TLP_USE_TWO_TWO 3 /* Use 2.2 behavior */
#define RACK_MIN_BW 8000 /* 64kbps in Bps */
#define MIN_GP_WIN 6 /* We need at least 6 MSS in a GP measurement */
#ifdef _KERNEL
#define RACK_OPTS_SIZE (sizeof(struct rack_opts_stats)/sizeof(uint64_t))
extern counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
#define RACK_OPTS_ADD(name, amm) counter_u64_add(rack_opts_arry[(offsetof(struct rack_opts_stats, name)/sizeof(uint64_t))], (amm))
#define RACK_OPTS_INC(name) RACK_OPTS_ADD(name, 1)
#endif
/*
* As we get each SACK we wade through the
* rc_map and mark off what is acked.
* We also increment rc_sacked as well.
*
* We also pay attention to missing entries
* based on the time and possibly mark them
* for retransmit. If we do and we are not already
* in recovery we enter recovery. In doing
* so we claer prr_delivered/holes_rxt and prr_sent_dur_rec.
* We also setup rc_next/rc_snd_nxt/rc_send_end so
* we will know where to send from. When not in
* recovery rc_next will be NULL and rc_snd_nxt should
* equal snd_max.
*
* Whenever we retransmit from recovery we increment
* rc_holes_rxt as we retran a block and mark it as retransmitted
* with the time it was sent. During non-recovery sending we
* add to our map and note the time down of any send expanding
* the rc_map at the tail and moving rc_snd_nxt up with snd_max.
*
* In recovery during SACK/ACK processing if a chunk has
* been retransmitted and it is now acked, we decrement rc_holes_rxt.
* When we retransmit from the scoreboard we use
* rc_next and rc_snd_nxt/rc_send_end to help us
* find what needs to be retran.
*
* To calculate pipe we simply take (snd_max - snd_una) + rc_holes_rxt
* This gets us the effect of RFC6675 pipe, counting twice for
* bytes retransmitted.
*/
#define TT_RACK_FR_TMR 0x2000
/*
* Locking for the rack control block.
* a) Locked by INP_WLOCK
* b) Locked by the hpts-mutex
*
*/
#define RACK_GP_HIST 4 /* How much goodput history do we maintain? */
struct rack_control {
/* Second cache line 0x40 from tcp_rack */
struct rack_rb_tree_head rc_mtree; /* Tree of all segments Lock(a) */
struct rack_head rc_tmap; /* List in transmit order Lock(a) */
struct rack_sendmap *rc_tlpsend; /* Remembered place for
* tlp_sending Lock(a) */
struct rack_sendmap *rc_resend; /* something we have been asked to
* resend */
uint32_t input_pkt;
uint32_t saved_input_pkt;
uint32_t rc_hpts_flags;
uint32_t rc_fixed_pacing_rate_ca;
uint32_t rc_fixed_pacing_rate_rec;
uint32_t rc_fixed_pacing_rate_ss;
uint32_t cwnd_to_use; /* The cwnd in use */
uint32_t rc_timer_exp; /* If a timer ticks of expiry */
uint32_t rc_rack_min_rtt; /* lowest RTT seen Lock(a) */
uint32_t rc_rack_largest_cwnd; /* Largest CWND we have seen Lock(a) */
/* Third Cache line 0x80 */
struct rack_head rc_free; /* Allocation array */
uint32_t rc_time_last_sent; /* Time we last sent some data and
* logged it Lock(a). */
uint32_t rc_reorder_ts; /* Last time we saw reordering Lock(a) */
uint32_t rc_tlp_new_data; /* we need to send new-data on a TLP
* Lock(a) */
uint32_t rc_prr_out; /* bytes sent during recovery Lock(a) */
uint32_t rc_prr_recovery_fs; /* recovery fs point Lock(a) */
uint32_t rc_prr_sndcnt; /* Prr sndcnt Lock(a) */
uint32_t rc_sacked; /* Tot sacked on scoreboard Lock(a) */
uint32_t xxx_rc_last_tlp_seq; /* Last tlp sequence Lock(a) */
uint32_t rc_prr_delivered; /* during recovery prr var Lock(a) */
uint16_t rc_tlp_cnt_out; /* count of times we have sent a TLP without new data */
uint16_t xxx_rc_tlp_seg_send_cnt; /* Number of times we have TLP sent
* rc_last_tlp_seq Lock(a) */
uint32_t rc_loss_count; /* How many bytes have been retransmitted
* Lock(a) */
uint32_t rc_reorder_fade; /* Socket option value Lock(a) */
/* Forth cache line 0xc0 */
/* Times */
uint32_t rc_rack_tmit_time; /* Rack transmit time Lock(a) */
uint32_t rc_holes_rxt; /* Tot retraned from scoreboard Lock(a) */
/* Variables to track bad retransmits and recover */
uint32_t rc_rsm_start; /* RSM seq number we retransmitted Lock(a) */
uint32_t rc_cwnd_at; /* cwnd at the retransmit Lock(a) */
uint32_t rc_ssthresh_at;/* ssthresh at the retransmit Lock(a) */
uint32_t rc_num_maps_alloced; /* Number of map blocks (sacks) we
* have allocated */
uint32_t rc_rcvtime; /* When we last received data */
uint32_t rc_num_split_allocs; /* num split map entries allocated */
uint32_t rc_last_output_to;
uint32_t rc_went_idle_time;
struct rack_sendmap *rc_sacklast; /* sack remembered place
* Lock(a) */
struct rack_sendmap *rc_rsm_at_retran; /* Debug variable kept for
* cache line alignment
* Lock(a) */
struct rack_sendmap *rc_first_appl; /* Pointer to first app limited */
struct rack_sendmap *rc_end_appl; /* Pointer to last app limited */
/* Cache line split 0x100 */
struct sack_filter rack_sf;
/* Cache line split 0x140 */
/* Flags for various things */
uint32_t last_pacing_time;
uint32_t rc_pace_max_segs;
uint32_t rc_pace_min_segs;
uint32_t rc_app_limited_cnt;
uint16_t rack_per_of_gp_ss; /* 100 = 100%, so from 65536 = 655 x bw */
uint16_t rack_per_of_gp_ca; /* 100 = 100%, so from 65536 = 655 x bw */
uint16_t rack_per_of_gp_rec; /* 100 = 100%, so from 65536 = 655 x bw, 0=off */
uint16_t rack_per_of_gp_probertt; /* 100 = 100%, so from 65536 = 655 x bw, 0=off */
uint32_t rc_high_rwnd;
uint32_t ack_count;
uint32_t sack_count;
uint32_t sack_noextra_move;
uint32_t sack_moved_extra;
struct rack_rtt_sample rack_rs;
const struct tcp_hwrate_limit_table *crte;
uint32_t rc_agg_early;
uint32_t rc_agg_delayed;
uint32_t rc_tlp_rxt_last_time;
uint32_t rc_saved_cwnd;
uint32_t rc_gp_output_ts;
uint32_t rc_gp_cumack_ts;
struct timeval act_rcv_time;
struct timeval rc_last_time_decay; /* SAD time decay happened here */
uint64_t gp_bw;
uint64_t init_rate;
#ifdef NETFLIX_SHARED_CWND
struct shared_cwnd *rc_scw;
#endif
uint64_t last_gp_comp_bw;
uint64_t last_max_bw; /* Our calculated max b/w last */
struct time_filter_small rc_gp_min_rtt;
int32_t rc_rtt_diff; /* Timely style rtt diff of our gp_srtt */
uint32_t rc_gp_srtt; /* Current GP srtt */
uint32_t rc_prev_gp_srtt; /* Previous RTT */
uint32_t rc_entry_gp_rtt; /* Entry to PRTT gp-rtt */
uint32_t rc_loss_at_start; /* At measurement window where was our lost value */
uint32_t forced_ack_ts;
uint32_t rc_lower_rtt_us_cts; /* Time our GP rtt was last lowered */
uint32_t rc_time_probertt_entered;
uint32_t rc_time_probertt_starts;
uint32_t rc_lowest_us_rtt;
uint32_t rc_highest_us_rtt;
uint32_t rc_last_us_rtt;
uint32_t rc_time_of_last_probertt;
uint32_t rc_target_probertt_flight;
uint32_t rc_probertt_sndmax_atexit; /* Highest sent to in probe-rtt */
uint32_t rc_gp_lowrtt; /* Lowest rtt seen during GPUT measurement */
uint32_t rc_gp_high_rwnd; /* Highest rwnd seen during GPUT measurement */
int32_t rc_scw_index;
uint32_t rc_tlp_threshold; /* Socket option value Lock(a) */
uint16_t rc_early_recovery_segs; /* Socket option value Lock(a) */
uint16_t rc_reorder_shift; /* Socket option value Lock(a) */
uint16_t rc_pkt_delay; /* Socket option value Lock(a) */
uint8_t rc_no_push_at_mrtt; /* No push when we exceed max rtt */
uint8_t num_avg; /* average count before we go to normal decay */
uint8_t rc_prop_rate; /* Socket option value Lock(a) */
uint8_t rc_prop_reduce; /* Socket option value Lock(a) */
uint8_t rc_tlp_cwnd_reduce; /* Socket option value Lock(a) */
uint8_t rc_early_recovery; /* Socket option value Lock(a) */
uint8_t rc_prr_sendalot;/* Socket option value Lock(a) */
uint8_t rc_min_to; /* Socket option value Lock(a) */
uint8_t rc_rate_sample_method;
uint8_t rc_gp_hist_idx;
};
#define RACK_TIMELY_CNT_BOOST 5 /* At 5th increase boost */
#define RACK_MINRTT_FILTER_TIM 10 /* Seconds */
#ifdef _KERNEL
struct tcp_rack {
/* First cache line 0x00 */
TAILQ_ENTRY(tcp_rack) r_hpts; /* hptsi queue next Lock(b) */
int32_t(*r_substate) (struct mbuf *, struct tcphdr *,
struct socket *, struct tcpcb *, struct tcpopt *,
int32_t, int32_t, uint32_t, int, int, uint8_t); /* Lock(a) */
struct tcpcb *rc_tp; /* The tcpcb Lock(a) */
struct inpcb *rc_inp; /* The inpcb Lock(a) */
uint32_t rc_free_cnt; /* Number of free entries on the rc_free list
* Lock(a) */
uint32_t rc_rack_rtt; /* RACK-RTT Lock(a) */
uint16_t r_mbuf_queue : 1, /* Do we do mbuf queue for non-paced */
rtt_limit_mul : 4, /* muliply this by low rtt */
r_limit_scw : 1,
r_avail_bits : 10; /* Available */
uint16_t rc_user_set_max_segs; /* Socket option value Lock(a) */
uint16_t forced_ack : 1,
rc_gp_incr : 1,
rc_gp_bwred : 1,
rc_gp_timely_inc_cnt : 3,
rc_gp_timely_dec_cnt : 3,
rc_not_backing_off: 1,
rc_highly_buffered: 1, /* The path is highly buffered */
rc_dragged_bottom: 1,
rc_dack_mode : 1, /* Mac O/S emulation of d-ack */
rc_dack_toggle : 1, /* For Mac O/S emulation of d-ack */
pacing_longer_than_rtt : 1,
rc_gp_filled : 1;
uint8_t r_state; /* Current rack state Lock(a) */
uint8_t rc_tmr_stopped : 7,
t_timers_stopped : 1;
uint8_t rc_enobuf : 7, /* count of enobufs on connection provides */
rc_on_min_to : 1;
uint8_t r_timer_override : 1, /* hpts override Lock(a) */
r_is_v6 : 1, /* V6 pcb Lock(a) */
rc_in_persist : 1,
rc_tlp_in_progress : 1,
rc_always_pace : 1, /* Socket option value Lock(a) */
rc_pace_to_cwnd : 1,
rc_pace_fill_if_rttin_range : 1,
xxx_avail_bits : 1;
uint8_t app_limited_needs_set : 1,
use_fixed_rate : 1,
rc_has_collapsed : 1,
r_rep_attack : 1,
r_rep_reverse : 1,
rack_hdrw_pacing : 1, /* We are doing Hardware pacing */
rack_hdw_pace_ena : 1, /* Is hardware pacing enabled? */
rack_attempt_hdwr_pace : 1; /* Did we attempt hdwr pacing (if allowed) */
uint8_t rack_tlp_threshold_use : 3, /* only 1, 2 and 3 used so far */
rack_rec_nonrxt_use_cr : 1,
rack_enable_scwnd : 1,
rack_attempted_scwnd : 1,
rack_no_prr : 1,
rack_scwnd_is_idle : 1;
uint8_t rc_allow_data_af_clo: 1,
delayed_ack : 1,
set_pacing_done_a_iw : 1,
use_rack_rr : 1,
alloc_limit_reported : 1,
sack_attack_disable : 1,
do_detection : 1,
rc_force_max_seg : 1;
uint8_t rack_cwnd_limited : 1,
r_early : 1,
r_late : 1,
r_running_early : 1,
r_running_late : 1,
r_wanted_output: 1,
r_rr_config : 2;
uint16_t rc_init_win : 8,
rc_gp_rtt_set : 1,
rc_gp_dyn_mul : 1,
rc_gp_saw_rec : 1,
rc_gp_saw_ca : 1,
rc_gp_saw_ss : 1,
rc_gp_no_rec_chg : 1,
in_probe_rtt : 1,
measure_saw_probe_rtt : 1;
/* Cache line 2 0x40 */
struct rack_control r_ctl;
} __aligned(CACHE_LINE_SIZE);
#endif
#endif
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