3 * Netflix Inc. All rights reserved.
4 * Author Randall R. Stewart
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #ifndef _NETINET_TCP_BBR_H_
31 #define _NETINET_TCP_BBR_H_
33 #define BBR_INITIAL_RTO 1000000 /* 1 second in micro-seconds */
35 #define BBR_ACKED 0x0001 /* The remote endpoint acked this */
36 #define BBR_WAS_RENEGED 0x0002 /* The peer reneged the ack */
37 #define BBR_RXT_CLEARED 0x0004 /* ACK Cleared by the RXT timer */
38 #define BBR_OVERMAX 0x0008 /* We have more retran's then we can
40 #define BBR_SACK_PASSED 0x0010 /* A sack was done above this block */
41 #define BBR_WAS_SACKPASS 0x0020 /* We retransmitted due to SACK pass */
42 #define BBR_HAS_FIN 0x0040 /* segment is sent with fin */
43 #define BBR_TLP 0x0080 /* segment sent as tail-loss-probe */
44 #define BBR_HAS_SYN 0x0100 /* segment has the syn */
45 #define BBR_MARKED_LOST 0x0200 /*
46 * This segments is lost and
47 * totaled into bbr->rc_ctl.rc_lost
49 #define BBR_RWND_COLLAPSED 0x0400 /* The peer collapsed the rwnd on the segment */
50 #define BBR_NUM_OF_RETRANS 7
52 /* Defines for socket options to set pacing overheads */
53 #define BBR_INCL_ENET_OH 0x01
54 #define BBR_INCL_IP_OH 0x02
55 #define BBR_INCL_TCP_OH 0x03
58 * With the addition of both measurement algorithms
59 * I had to move over the size of a
60 * cache line (unfortunately). For now there is
61 * no way around this. We may be able to cut back
62 * at some point I hope.
65 TAILQ_ENTRY(bbr_sendmap) r_next; /* seq number arrayed next */
66 TAILQ_ENTRY(bbr_sendmap) r_tnext; /* Time of tmit based next */
67 uint32_t r_start; /* Sequence number of the segment */
68 uint32_t r_end; /* End seq, this is 1 beyond actually */
70 uint32_t r_rtr_bytes; /* How many bytes have been retransmitted */
71 uint32_t r_delivered; /* Delivered amount at send */
73 uint32_t r_del_time; /* The time of the last delivery update */
74 uint8_t r_rtr_cnt:4, /* Retran count, index this -1 to get time
77 r_is_drain:1, /* In a draining cycle */
78 r_app_limited:1,/* We went app limited */
79 r_ts_valid:1; /* Timestamp field is valid (r_del_ack_ts) */
80 uint8_t r_dupack; /* Dup ack count */
81 uint8_t r_in_tmap:1, /* Flag to see if its in the r_tnext array */
82 r_is_smallmap:1,/* Was logged as a small-map send-map item */
83 r_is_gain:1, /* Was in gain cycle */
84 r_bbr_state:5; /* The BBR state at send */
85 uint8_t r_limit_type; /* is this entry counted against a limit? */
87 uint16_t r_flags; /* Flags as defined above */
89 uint32_t r_del_ack_ts; /* At send what timestamp of peer was (if r_ts_valid set) */
90 /****************Cache line*****************/
91 uint32_t r_tim_lastsent[BBR_NUM_OF_RETRANS];
93 * Question, should we instead just grab the sending b/w
94 * from the filter with the gain and store it in a
97 uint32_t r_first_sent_time; /* Time of first pkt in flight sent */
98 uint32_t r_pacing_delay; /* pacing delay of this send */
99 uint32_t r_flight_at_send; /* flight at the time of the send */
101 } __aligned(CACHE_LINE_SIZE);
105 #define BBR_LIMIT_TYPE_SPLIT 1
107 TAILQ_HEAD(bbr_head, bbr_sendmap);
109 #define BBR_SEGMENT_TIME_SIZE 1500 /* How many bytes in time_between */
111 #define BBR_MIN_SEG 1460 /* MSS size */
112 #define BBR_MAX_GAIN_VALUE 0xffff
114 #define BBR_TIMER_FUDGE 1500 /* 1.5ms in micro seconds */
116 /* BW twiddle secret codes */
117 #define BBR_RED_BW_CONGSIG 0 /* We enter recovery and set using b/w */
118 #define BBR_RED_BW_RATECAL 1 /* We are calculating the loss rate */
119 #define BBR_RED_BW_USELRBW 2 /* We are dropping the lower b/w with
121 #define BBR_RED_BW_SETHIGHLOSS 3 /* We have set our highloss value at
122 * exit from probe-rtt */
123 #define BBR_RED_BW_PE_CLREARLY 4 /* We have decided to clear the
125 #define BBR_RED_BW_PE_CLAFDEL 5 /* We are clearing it on schedule
127 #define BBR_RED_BW_REC_ENDCLL 6 /* Recover exits save high if needed
128 * an clear to start measuring */
129 #define BBR_RED_BW_PE_NOEARLY_OUT 7 /* Set pkt epoch judged that we do not
130 * get out of jail early */
131 /* For calculating a rate */
132 #define BBR_CALC_BW 1
133 #define BBR_CALC_LOSS 2
135 #define BBR_RTT_BY_TIMESTAMP 0
136 #define BBR_RTT_BY_EXACTMATCH 1
137 #define BBR_RTT_BY_EARLIER_RET 2
138 #define BBR_RTT_BY_THIS_RETRAN 3
139 #define BBR_RTT_BY_SOME_RETRAN 4
140 #define BBR_RTT_BY_TSMATCHING 5
142 /* Markers to track where we enter persists from */
143 #define BBR_PERSISTS_FROM_1 1
144 #define BBR_PERSISTS_FROM_2 2
145 #define BBR_PERSISTS_FROM_3 3
146 #define BBR_PERSISTS_FROM_4 4
147 #define BBR_PERSISTS_FROM_5 5
149 /* magic cookies to ask for the RTT */
150 #define BBR_RTT_PROP 0
151 #define BBR_RTT_RACK 1
152 #define BBR_RTT_PKTRTT 2
156 #define BBR_CUM_ACKED 1
158 /* threshold in useconds where we consider we need a higher min cwnd */
159 #define BBR_HIGH_SPEED 1000
160 #define BBR_HIGHSPEED_NUM_MSS 12
162 #define MAX_REDUCE_RXT 3 /* What is the maximum times we are willing to
163 * reduce b/w in RTX's. Setting this has a
164 * multiplicative effect e.g. if we are
165 * reducing by 20% then setting it to 3 means
166 * you will have reduced the b/w estimate by >
167 * 60% before you stop. */
169 * We use the rate sample structure to
170 * assist in single sack/ack rate and rtt
171 * calculation. In the future we will expand
172 * this in BBR to do forward rate sample
175 #define BBR_RS_RTT_EMPTY 0x00000001 /* Nothing yet stored in RTT's */
176 #define BBR_RS_BW_EMPTY 0x00000002 /* Nothing yet stored in cDR */
177 #define BBR_RS_RTT_VALID 0x00000004 /* We have at least one valid RTT */
178 #define BBR_RS_BW_VAILD 0x00000008 /* We have a valid cDR */
179 #define BBR_RS_EMPTY (BBR_RS_RTT_EMPTY|BBR_RS_BW_EMPTY)
180 struct bbr_rtt_sample {
182 uint32_t rs_rtt_lowest;
183 uint32_t rs_rtt_lowest_sendtime;
184 uint32_t rs_rtt_low_seq_start;
186 uint32_t rs_rtt_highest;
191 uint32_t cur_rtt_bytecnt;
193 uint32_t cur_rtt_rsmcnt;
194 uint32_t rc_crtt_set:1,
199 /* RTT shrink reasons */
200 #define BBR_RTTS_INIT 0
201 #define BBR_RTTS_NEWRTT 1
202 #define BBR_RTTS_RTTPROBE 2
203 #define BBR_RTTS_WASIDLE 3
204 #define BBR_RTTS_PERSIST 4
205 #define BBR_RTTS_REACHTAR 5
206 #define BBR_RTTS_ENTERPROBE 6
207 #define BBR_RTTS_SHRINK_PG 7
208 #define BBR_RTTS_SHRINK_PG_FINAL 8
209 #define BBR_RTTS_NEW_TARGET 9
210 #define BBR_RTTS_LEAVE_DRAIN 10
211 #define BBR_RTTS_RESETS_VALUES 11
213 #define BBR_NUM_RATES 5
215 #define BBR_RT_FLAG_FREE 0x00 /* Is on the free list */
216 #define BBR_RT_FLAG_INUSE 0x01 /* Has been allocated */
217 #define BBR_RT_FLAG_READY 0x02 /* Ready to initiate a measurement. */
218 #define BBR_RT_FLAG_CAPPED_PRE 0x04 /* Ready to cap if we send the next segment */
219 #define BBR_RT_FLAG_CAPPED 0x08 /* Measurement is capped */
220 #define BBR_RT_FLAG_PASTFA 0x10 /* Past the first ack. */
221 #define BBR_RT_FLAG_LIMITED 0x20 /* Saw application/cwnd or rwnd limited period */
222 #define BBR_RT_SEEN_A_ACK 0x40 /* A ack has been saved */
223 #define BBR_RT_PREV_RTT_SET 0x80 /* There was a RTT set in */
224 #define BBR_RT_PREV_SEND_TIME 0x100 /*
225 *There was a RTT send time set that can be used
228 #define BBR_RT_SET_GRADIENT 0x200
229 #define BBR_RT_TS_VALID 0x400
234 struct bbr_sendmap *rsm; /* For alloc/free */
235 uint64_t sb_acc; /* For out/ack or t-o */
247 uint32_t target_cwnd; /* UU */
248 uint32_t inflight; /* UU */
249 uint32_t applimited; /* UU */
251 uint32_t delivered; /* UU */
252 uint64_t cur_del_rate; /* UU */
253 uint64_t delRate; /* UU */
254 uint64_t rttProp; /* UU */
255 uint64_t lt_bw; /* UU */
258 uint32_t slot; /* UU */
263 uint32_t hptsi_gain; /* UU */
264 uint32_t cwnd_gain; /* UU */
265 uint32_t epoch; /* UU */
266 uint32_t lt_epoch; /* UU */
268 uint32_t blk_start[4]; /* xx */
270 uint32_t len; /* Timeout T3=1, TLP=2, RACK=3 */
273 uint8_t applied; /* UU */
274 uint8_t inhpts; /* UU */
275 uint8_t ininput; /* UU */
276 uint8_t use_lt_bw; /* UU */
279 struct bbr_log_sysctl_out {
281 uint32_t bbr_log_max;
282 struct bbr_log entries[0];
286 * Magic numbers for logging timeout events if the
287 * logging is enabled.
289 #define BBR_TO_FRM_TMR 1
290 #define BBR_TO_FRM_TLP 2
291 #define BBR_TO_FRM_RACK 3
292 #define BBR_TO_FRM_KEEP 4
293 #define BBR_TO_FRM_PERSIST 5
294 #define BBR_TO_FRM_DELACK 6
296 #define BBR_SEES_STRETCH_ACK 1
297 #define BBR_SEES_COMPRESSED_ACKS 2
301 * As we get each SACK we wade through the
302 * rc_map and mark off what is acked.
303 * We also increment rc_sacked as well.
305 * We also pay attention to missing entries
306 * based on the time and possibly mark them
307 * for retransmit. If we do and we are not already
308 * in recovery we enter recovery. In doing
309 * so we claer prr_delivered/holes_rxt and prr_sent_dur_rec.
310 * We also setup rc_next/rc_snd_nxt/rc_send_end so
311 * we will know where to send from. When not in
312 * recovery rc_next will be NULL and rc_snd_nxt should
315 * Whenever we retransmit from recovery we increment
316 * rc_holes_rxt as we retran a block and mark it as retransmitted
317 * with the time it was sent. During non-recovery sending we
318 * add to our map and note the time down of any send expanding
319 * the rc_map at the tail and moving rc_snd_nxt up with snd_max.
321 * In recovery during SACK/ACK processing if a chunk has
322 * been retransmitted and it is now acked, we decrement rc_holes_rxt.
323 * When we retransmit from the scoreboard we use
324 * rc_next and rc_snd_nxt/rc_send_end to help us
325 * find what needs to be retran.
327 * To calculate pipe we simply take (snd_max - snd_una) + rc_holes_rxt
328 * This gets us the effect of RFC6675 pipe, counting twice for
329 * bytes retransmitted.
332 #define TT_BBR_FR_TMR 0x2001
335 #define BBR_UNIT (1 << BBR_SCALE)
337 #define BBR_NUM_RTTS_FOR_DEL_LIMIT 8 /* How many pkt-rtts do we keep
338 * Delivery rate for */
339 #define BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT 10 /* How many pkt-rtts do we keep
340 * Delivery rate for google */
342 #define BBR_SECONDS_NO_RTT 10 /* 10 seconds with no RTT shrinkage */
343 #define BBR_PROBERTT_MAX 200 /* 200ms */
344 #define BBR_PROBERTT_NUM_MSS 4
345 #define BBR_STARTUP_EPOCHS 3
346 #define USECS_IN_MSEC 1000
347 #define BBR_TIME_TO_SECONDS(a) (a / USECS_IN_SECOND)
348 #define BBR_TIME_TO_MILLI(a) (a / MS_IN_USEC)
351 /* BBR keeps time in usec's so we divide by 1000 and round up */
352 #define BBR_TS_TO_MS(t) ((t+999)/MS_IN_USEC)
355 * Locking for the rack control block.
356 * a) Locked by INP_WLOCK
357 * b) Locked by the hpts-mutex
360 #define BBR_STATE_STARTUP 0x01
361 #define BBR_STATE_DRAIN 0x02
362 #define BBR_STATE_PROBE_BW 0x03
363 #define BBR_STATE_PROBE_RTT 0x04
364 #define BBR_STATE_IDLE_EXIT 0x05
366 /* Substate defines for STATE == PROBE_BW */
367 #define BBR_SUB_GAIN 0 /* State 0 where we are 5/4 BBR_UNIT */
368 #define BBR_SUB_DRAIN 1 /* State 1 where we are at 3/4 BBR_UNIT */
369 #define BBR_SUB_LEVEL1 2 /* State 1 first BBR_UNIT */
370 #define BBR_SUB_LEVEL2 3 /* State 2nd BBR_UNIT */
371 #define BBR_SUB_LEVEL3 4 /* State 3rd BBR_UNIT */
372 #define BBR_SUB_LEVEL4 5 /* State 4th BBR_UNIT */
373 #define BBR_SUB_LEVEL5 6 /* State 5th BBR_UNIT */
374 #define BBR_SUB_LEVEL6 7 /* State last BBR_UNIT */
375 #define BBR_SUBSTATE_COUNT 8
377 /* Single remaining reduce log */
378 #define BBR_REDUCE_AT_FR 5
380 #define BBR_BIG_LOG_SIZE 300000
383 uint64_t bbr_badfr; /* 0 */
384 uint64_t bbr_badfr_bytes; /* 1 */
385 uint64_t bbr_saw_oerr; /* 2 */
386 uint64_t bbr_saw_emsgsiz; /* 3 */
387 uint64_t bbr_reorder_seen; /* 4 */
388 uint64_t bbr_tlp_tot; /* 5 */
389 uint64_t bbr_tlp_newdata; /* 6 */
390 uint64_t bbr_offset_recovery; /* 7 */
391 uint64_t bbr_tlp_retran_fail; /* 8 */
392 uint64_t bbr_to_tot; /* 9 */
393 uint64_t bbr_to_arm_rack; /* 10 */
394 uint64_t bbr_enter_probertt; /* 11 */
395 uint64_t bbr_tlp_set; /* 12 */
396 uint64_t bbr_resends_set; /* 13 */
397 uint64_t bbr_force_output; /* 14 */
398 uint64_t bbr_to_arm_tlp; /* 15 */
399 uint64_t bbr_paced_segments; /* 16 */
400 uint64_t bbr_saw_enobuf; /* 17 */
401 uint64_t bbr_to_alloc_failed; /* 18 */
402 uint64_t bbr_to_alloc_emerg; /* 19 */
403 uint64_t bbr_sack_proc_all; /* 20 */
404 uint64_t bbr_sack_proc_short; /* 21 */
405 uint64_t bbr_sack_proc_restart; /* 22 */
406 uint64_t bbr_to_alloc; /* 23 */
407 uint64_t bbr_offset_drop; /* 24 */
408 uint64_t bbr_runt_sacks; /* 25 */
409 uint64_t bbr_sack_passed; /* 26 */
410 uint64_t bbr_rlock_left_ret0; /* 27 */
411 uint64_t bbr_rlock_left_ret1; /* 28 */
412 uint64_t bbr_dynamic_rwnd; /* 29 */
413 uint64_t bbr_static_rwnd; /* 30 */
414 uint64_t bbr_sack_blocks; /* 31 */
415 uint64_t bbr_sack_blocks_skip; /* 32 */
416 uint64_t bbr_sack_search_both; /* 33 */
417 uint64_t bbr_sack_search_fwd; /* 34 */
418 uint64_t bbr_sack_search_back; /* 35 */
419 uint64_t bbr_plain_acks; /* 36 */
420 uint64_t bbr_acks_with_sacks; /* 37 */
421 uint64_t bbr_progress_drops; /* 38 */
422 uint64_t bbr_early; /* 39 */
423 uint64_t bbr_reneges_seen; /* 40 */
424 uint64_t bbr_persist_reneg; /* 41 */
425 uint64_t bbr_dropped_af_data; /* 42 */
426 uint64_t bbr_failed_mbuf_aloc; /* 43 */
427 uint64_t bbr_cwnd_limited; /* 44 */
428 uint64_t bbr_rwnd_limited; /* 45 */
429 uint64_t bbr_app_limited; /* 46 */
430 uint64_t bbr_force_timer_start; /* 47 */
431 uint64_t bbr_hpts_min_time; /* 48 */
432 uint64_t bbr_meets_tso_thresh; /* 49 */
433 uint64_t bbr_miss_tso_rwnd; /* 50 */
434 uint64_t bbr_miss_tso_cwnd; /* 51 */
435 uint64_t bbr_miss_tso_app; /* 52 */
436 uint64_t bbr_miss_retran; /* 53 */
437 uint64_t bbr_miss_tlp; /* 54 */
438 uint64_t bbr_miss_unknown; /* 55 */
439 uint64_t bbr_hdwr_rl_add_ok; /* 56 */
440 uint64_t bbr_hdwr_rl_add_fail; /* 57 */
441 uint64_t bbr_hdwr_rl_mod_ok; /* 58 */
442 uint64_t bbr_hdwr_rl_mod_fail; /* 59 */
443 uint64_t bbr_collapsed_win; /* 60 */
444 uint64_t bbr_alloc_limited; /* 61 */
445 uint64_t bbr_alloc_limited_conns; /* 62 */
446 uint64_t bbr_split_limited; /* 63 */
450 * The structure bbr_opt_stats is a simple
451 * way to see how many options are being
452 * changed in the stack.
454 struct bbr_opts_stats {
455 uint64_t tcp_bbr_pace_per_sec;
456 uint64_t tcp_bbr_pace_del_tar;
457 uint64_t tcp_bbr_pace_seg_max;
458 uint64_t tcp_bbr_pace_seg_min;
459 uint64_t tcp_bbr_pace_cross;
460 uint64_t tcp_bbr_drain_inc_extra;
461 uint64_t tcp_bbr_unlimited;
462 uint64_t tcp_bbr_iwintso;
463 uint64_t tcp_bbr_rec_over_hpts;
464 uint64_t tcp_bbr_recforce;
465 uint64_t tcp_bbr_startup_pg;
466 uint64_t tcp_bbr_drain_pg;
467 uint64_t tcp_bbr_rwnd_is_app;
468 uint64_t tcp_bbr_probe_rtt_int;
469 uint64_t tcp_bbr_one_retran;
470 uint64_t tcp_bbr_startup_loss_exit;
471 uint64_t tcp_bbr_use_lowgain;
472 uint64_t tcp_bbr_lowgain_thresh;
473 uint64_t tcp_bbr_lowgain_half;
474 uint64_t tcp_bbr_lowgain_fd;
475 uint64_t tcp_bbr_usedel_rate;
476 uint64_t tcp_bbr_min_rto;
477 uint64_t tcp_bbr_max_rto;
478 uint64_t tcp_rack_pace_max_seg;
479 uint64_t tcp_rack_min_to;
480 uint64_t tcp_rack_reord_thresh;
481 uint64_t tcp_rack_reord_fade;
482 uint64_t tcp_rack_tlp_thresh;
483 uint64_t tcp_rack_pkt_delay;
484 uint64_t tcp_bbr_startup_exit_epoch;
485 uint64_t tcp_bbr_ack_comp_alg;
486 uint64_t tcp_rack_cheat;
487 uint64_t tcp_iwnd_tso;
488 uint64_t tcp_utter_max_tso;
489 uint64_t tcp_hdwr_pacing;
490 uint64_t tcp_extra_state;
491 uint64_t tcp_floor_min_tso;
493 uint64_t tcp_bbr_algorithm;
494 uint64_t tcp_bbr_tslimits;
495 uint64_t tcp_bbr_probertt_len;
496 uint64_t tcp_bbr_probertt_gain;
497 uint64_t tcp_bbr_topaceout;
498 uint64_t tcp_use_rackcheat;
500 uint64_t tcp_maxpeak;
501 uint64_t tcp_retran_wtso;
502 uint64_t tcp_data_ac;
503 uint64_t tcp_ts_raises;
504 uint64_t tcp_pacing_oh_tmr;
505 uint64_t tcp_pacing_oh;
506 uint64_t tcp_policer_det;
511 #define BBR_STAT_SIZE (sizeof(struct bbr_stats)/sizeof(uint64_t))
512 extern counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
513 #define BBR_STAT_ADD(name, amm) counter_u64_add(bbr_stat_arry[(offsetof(struct bbr_stats, name)/sizeof(uint64_t))], (amm))
514 #define BBR_STAT_INC(name) BBR_STAT_ADD(name, 1)
515 #define BBR_OPTS_SIZE (sizeof(struct bbr_stats)/sizeof(uint64_t))
516 extern counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
517 #define BBR_OPTS_ADD(name, amm) counter_u64_add(bbr_opts_arry[(offsetof(struct bbr_opts_stats, name)/sizeof(uint64_t))], (amm))
518 #define BBR_OPTS_INC(name) BBR_OPTS_ADD(name, 1)
521 #define BBR_NUM_LOSS_RATES 3
522 #define BBR_NUM_BW_RATES 3
524 #define BBR_RECOVERY_LOWRTT 1
525 #define BBR_RECOVERY_MEDRTT 2
526 #define BBR_RECOVERY_HIGHRTT 3
527 #define BBR_RECOVERY_EXTREMERTT 4
531 /*******************************/
532 /* Cache line 2 from bbr start */
533 /*******************************/
534 struct bbr_head rc_map; /* List of all segments Lock(a) */
535 struct bbr_head rc_tmap; /* List in transmit order Lock(a) */
536 struct bbr_sendmap *rc_resend; /* something we have been asked to
538 uint32_t rc_last_delay_val; /* How much we expect to delay Lock(a) */
539 uint32_t rc_bbr_hptsi_gain:16, /* Current hptsi gain Lock(a) */
540 rc_hpts_flags:16; /* flags on whats on the pacer wheel */
542 uint32_t rc_delivered; /* BRR delivered amount Lock(a) */
543 uint32_t rc_hptsi_agg_delay; /* How much time are we behind */
545 uint32_t rc_flight_at_input;
546 uint32_t rc_lost_bytes; /* Total bytes currently marked lost */
547 /*******************************/
548 /* Cache line 3 from bbr start */
549 /*******************************/
550 struct time_filter rc_delrate;
551 /*******************************/
552 /* Cache line 4 from bbr start */
553 /*******************************/
554 struct bbr_head rc_free; /* List of Free map entries Lock(a) */
555 struct bbr_sendmap *rc_tlp_send; /* something we have been
557 uint32_t rc_del_time;
558 uint32_t rc_target_at_state; /* Target for a state */
560 uint16_t rc_free_cnt; /* Number of free entries on the rc_free list
562 uint16_t rc_startup_pg;
564 uint32_t cur_rtt; /* Last RTT from ack */
567 uint32_t rc_went_idle_time; /* Used for persits to see if its
568 * probe-rtt qualified */
569 uint32_t rc_pace_max_segs:17, /* How much in any single TSO we send Lock(a) */
570 rc_pace_min_segs:15; /* The minimum single segment size before we enter persists */
572 uint32_t rc_rtt_shrinks; /* Time of last rtt shrinkage Lock(a) */
573 uint32_t r_app_limited_until;
574 uint32_t rc_timer_exp; /* If a timer ticks of expiry */
575 uint32_t rc_rcv_epoch_start; /* Start time of the Epoch Lock(a) */
577 /*******************************/
578 /* Cache line 5 from bbr start */
579 /*******************************/
581 uint32_t rc_lost_at_pktepoch; /* what the lost value was at the last
583 uint32_t r_measurement_count; /* count of measurement applied lock(a) */
586 uint32_t rc_last_tlp_seq; /* Last tlp sequence Lock(a) */
587 uint16_t rc_reorder_shift; /* Socket option value Lock(a) */
588 uint16_t rc_pkt_delay; /* Socket option value Lock(a) */
590 struct bbr_sendmap *rc_sacklast; /* sack remembered place
592 struct bbr_sendmap *rc_next; /* remembered place where we next
593 * retransmit at Lock(a) */
595 uint32_t rc_sacked; /* Tot sacked on scoreboard Lock(a) */
596 uint32_t rc_holes_rxt; /* Tot retraned from scoreboard Lock(a) */
598 uint32_t rc_reorder_ts; /* Last time we saw reordering Lock(a) */
599 uint32_t rc_init_rwnd; /* Initial rwnd when we transitioned */
601 * used only initial and close
603 uint32_t rc_high_rwnd; /* Highest rwnd seen */
604 uint32_t rc_lowest_rtt; /* Smallest RTT we have seen */
606 uint32_t rc_last_rtt; /* Last valid measured RTT that ack'd data */
607 uint32_t bbr_cross_over;
609 /*******************************/
610 /* Cache line 6 from bbr start */
611 /*******************************/
612 struct sack_filter bbr_sf;
614 /*******************************/
615 /* Cache line 7 from bbr start */
616 /*******************************/
617 struct time_filter_small rc_rttprop;
618 uint32_t last_inbound_ts; /* Peers last timestamp */
620 uint32_t rc_inc_tcp_oh: 1,
625 uint32_t rc_lt_epoch_use; /* When we started lt-bw use Lock(a) */
627 uint32_t rc_recovery_start; /* Time we start recovery Lock(a) */
628 uint32_t rc_lt_del; /* Delivered at lt bw sampling start Lock(a) */
630 uint64_t rc_bbr_cur_del_rate; /* Current measured delivery rate
633 /*******************************/
634 /* Cache line 8 from bbr start */
635 /*******************************/
636 uint32_t rc_cwnd_on_ent; /* On entry to recovery the cwnd
638 uint32_t rc_agg_early; /* aggregate amount early */
640 uint32_t rc_rcvtime; /* When we last received data Lock(a) */
641 uint32_t rc_pkt_epoch_del; /* seq num that we need for RTT epoch */
643 uint32_t rc_pkt_epoch; /* Epoch based on packet RTTs */
644 uint32_t rc_pkt_epoch_time; /* Time we started the pkt epoch */
646 uint32_t rc_pkt_epoch_rtt; /* RTT using the packet epoch */
647 uint32_t rc_rtt_epoch; /* Current RTT epoch, it ticks every rttProp
650 uint32_t bbr_smallest_srtt_this_state;
652 uint32_t rc_lt_epoch; /* LT epoch start of bw_sampling */
653 uint32_t rc_lost_at_startup;
655 uint32_t rc_bbr_state_atflight;
656 uint32_t rc_bbr_last_startup_epoch; /* Last startup epoch where we
658 uint32_t rc_bbr_enters_probertt; /* Timestamp we entered
659 * probertt Lock(a) */
660 uint32_t rc_lt_time; /* Time of lt sampling start Lock(a) */
662 /*******************************/
663 /* Cache line 9 from bbr start */
664 /*******************************/
665 uint64_t rc_lt_bw; /* LT bw calculated Lock(a) */
666 uint64_t rc_bbr_lastbtlbw; /* For startup, what was last btlbw I
667 * saw to check the 20% gain Lock(a) */
670 uint32_t rc_bbr_cwnd_gain; /* Current cwnd gain Lock(a) */
671 uint32_t rc_pkt_epoch_loss_rate; /* pkt-epoch loss rate */
673 uint32_t rc_saved_cwnd; /* Saved cwnd during Probe-rtt drain Lock(a) */
674 uint32_t substate_pe;
676 uint32_t rc_lost; /* Number of bytes lost Lock(a) */
677 uint32_t rc_exta_time_gd; /* How much extra time we got in d/g */
679 uint32_t rc_lt_lost; /* Number of lt bytes lost at sampling start
681 uint32_t rc_bbr_state_time;
683 uint32_t rc_min_to; /* Socket option value Lock(a) */
684 uint32_t rc_initial_hptsi_bw; /* Our initial startup bw Lock(a) */
686 uint32_t bbr_lost_at_state; /* Temp counter debug lost value as we
688 /*******************************/
689 /* Cache line 10 from bbr start */
690 /*******************************/
691 uint32_t rc_level_state_extra;
692 uint32_t rc_red_cwnd_pe;
693 const struct tcp_hwrate_limit_table *crte;
696 uint32_t rc_probertt_int;
697 uint32_t rc_probertt_srttchktim; /* Time we last did a srtt
699 uint32_t gain_epoch; /* Epoch we should be out of gain */
700 uint32_t rc_min_rto_ms;
702 uint32_t rc_reorder_fade; /* Socket option value Lock(a) */
703 uint32_t last_startup_measure;
705 int32_t bbr_hptsi_per_second;
706 int32_t bbr_hptsi_segments_delay_tar;
708 int32_t bbr_hptsi_segments_max;
709 uint32_t bbr_rttprobe_gain_val;
710 /*******************************/
711 /* Cache line 11 from bbr start */
712 /*******************************/
713 uint32_t cur_rtt_send_time; /* Time we sent our rtt measured packet */
714 uint32_t bbr_peer_tsratio; /* Our calculated ts ratio to multply */
715 uint32_t bbr_ts_check_tstmp; /* When we filled it the TS that came on the ack */
716 uint32_t bbr_ts_check_our_cts; /* When we filled it the cts of the send */
717 uint32_t rc_tlp_rxt_last_time;
718 uint32_t bbr_smallest_srtt_state2;
719 uint32_t bbr_hdwr_cnt_noset_snt; /* count of hw pacing sends during delay */
720 uint32_t startup_last_srtt;
721 uint32_t rc_ack_hdwr_delay;
722 uint32_t highest_hdwr_delay; /* Largest delay we have seen from hardware */
723 uint32_t non_gain_extra;
724 uint32_t recovery_lr; /* The sum of the loss rate from the pe's during recovery */
725 uint32_t last_in_probertt;
726 uint32_t flightsize_at_drain; /* In draining what was the last marked flight size */
727 uint32_t rc_pe_of_prtt; /* PE we went into probe-rtt */
728 uint32_t ts_in; /* ts that went with the last rtt */
730 uint16_t rc_tlp_seg_send_cnt; /* Number of times we have TLP sent
731 * rc_last_tlp_seq Lock(a) */
732 uint16_t rc_drain_pg;
733 uint32_t rc_num_maps_alloced; /* num send map entries allocated */
734 uint32_t rc_num_split_allocs; /* num split map entries allocated */
735 uint16_t rc_num_small_maps_alloced; /* Number of sack blocks
737 uint16_t bbr_hptsi_bytes_min;
739 uint16_t bbr_hptsi_segments_floor;
740 uint16_t bbr_utter_max;
741 uint16_t bbr_google_discount;
748 /* First cache line 0x00 */
749 int32_t(*r_substate) (struct mbuf *, struct tcphdr *,
750 struct socket *, struct tcpcb *, struct tcpopt *,
751 int32_t, int32_t, uint32_t, int32_t, int32_t); /* Lock(a) */
752 struct tcpcb *rc_tp; /* The tcpcb Lock(a) */
753 struct inpcb *rc_inp; /* The inpcb Lock(a) */
754 struct timeval rc_tv;
755 uint32_t rc_pacer_started; /* Time we started the pacer */
756 uint16_t no_pacing_until:8, /* No pacing until N packet epochs */
757 ts_can_raise:1,/* TS b/w calculations can raise the bw higher */
758 skip_gain:1, /* Skip the gain cycle (hardware pacing) */
759 gain_is_limited:1, /* With hardware pacing we are limiting gain */
762 hw_pacing_set:1; /* long enough has passed for us to start pacing */
763 uint16_t xxx_r_ack_count; /* During recovery count of ack's received
764 * that added data since output */
765 uint16_t bbr_segs_rcvd; /* In Segment count since we sent a ack */
767 uint8_t bbr_timer_src:4, /* Used for debugging Lock(a) */
768 bbr_use_rack_cheat:1, /* Use the rack cheat */
769 bbr_init_win_cheat:1, /* Send full IW for TSO */
770 bbr_attempt_hdwr_pace:1,/* Try to do hardware pacing */
771 bbr_hdrw_pacing:1; /* Hardware pacing is available */
772 uint8_t bbr_hdw_pace_ena:1, /* Does the connection allow hardware pacing to be attempted */
773 bbr_prev_in_rec:1, /* We were previously in recovery */
775 use_policer_detection:1,
776 xxx_bbr_hdw_pace_idx:4; /* If hardware pacing is on, index to slot in pace tbl */
777 uint16_t r_wanted_output:1,
780 rc_output_starts_timer:1,
781 rc_resends_use_tso:1,
782 rc_all_timers_stopped:1,
784 rc_ack_was_delayed:1,
791 rc_is_pkt_epoch_now:1,
794 uint8_t r_state:4, /* Current bbr state Lock(a) */
795 r_agg_early_set:1, /* Did we get called early */
797 r_use_policer:1, /* For google mode only */
799 uint8_t r_timer_override:1, /* pacer override Lock(a) 0/1 */
802 rc_allow_data_af_clo:1,
803 rc_tlp_rtx_out:1, /* A TLP is in flight */
804 rc_tlp_in_progress:1, /* a TLP timer is running needed? */
805 rc_use_idle_restart:1; /* Do we restart fast after idle (persist or applim) */
806 uint8_t rc_bbr_state:3, /* What is the major BBR state */
807 rc_bbr_substate:3, /* For probeBW state */
810 uint8_t rc_last_options;
811 uint8_t rc_tlp_threshold; /* Socket option value Lock(a) */
812 uint8_t rc_max_rto_sec;
813 uint8_t rc_cwnd_limited:1, /* We are cwnd limited */
814 rc_tmr_stopped:7; /* What timers have been stopped */
815 uint8_t rc_use_google:1,
817 rc_ts_data_set:1, /* We have filled a set point to determine */
818 rc_ts_clock_set:1, /* We have determined the ts type */
819 rc_ts_cant_be_used:1, /* We determined we can't use ts values */
822 alloc_limit_reported:1;
824 /* Cache line 2 0x40 */
825 struct bbr_control r_ctl;
827 } __aligned(CACHE_LINE_SIZE);