xref: /freebsd/sys/netinet/tcp_stacks/tcp_rack.h (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 
28 #ifndef _NETINET_TCP_RACK_H_
29 #define _NETINET_TCP_RACK_H_
30 
31 #define RACK_ACKED	    0x0001/* The remote endpoint acked this */
32 #define RACK_TO_MIXED	    0x0002/* A timeout occured that mixed the send order - not used */
33 #define RACK_DEFERRED	    0x0004/* We can't use this for RTT calc - not used */
34 #define RACK_OVERMAX	    0x0008/* We have more retran's then we can fit */
35 #define RACK_SACK_PASSED    0x0010/* A sack was done above this block */
36 #define RACK_WAS_SACKPASS   0x0020/* We retransmitted due to SACK pass */
37 #define RACK_HAS_FIN	    0x0040/* segment is sent with fin */
38 #define RACK_TLP	    0x0080/* segment sent as tail-loss-probe */
39 #define RACK_RWND_COLLAPSED 0x0100/* The peer collapsed the rwnd on the segment */
40 #define RACK_APP_LIMITED    0x0200/* We went app limited after this send */
41 #define RACK_WAS_ACKED	    0x0400/* a RTO undid the ack, but it already had a rtt calc done */
42 #define RACK_HAS_SIN	    0x0800/* SIN is on this guy */
43 #define RACK_NUM_OF_RETRANS 3
44 
45 #define RACK_INITIAL_RTO 1000 /* 1 second in milli seconds */
46 
47 #define RACK_REQ_AVG 4 	/* Must be less than 256 */
48 
49 struct rack_sendmap {
50 	uint32_t r_start;	/* Sequence number of the segment */
51 	uint32_t r_end;		/* End seq, this is 1 beyond actually */
52 	TAILQ_ENTRY(rack_sendmap) r_tnext;	/* Time of transmit based next */
53 	RB_ENTRY(rack_sendmap) r_next;		/* RB Tree next */
54 	uint32_t r_rtr_bytes;	/* How many bytes have been retransmitted */
55 	uint16_t r_rtr_cnt;	/* Retran count, index this -1 to get time
56 				 * sent */
57 	uint16_t r_flags;	/* Flags as defined above */
58 	uint32_t r_tim_lastsent[RACK_NUM_OF_RETRANS];
59 	uint32_t usec_orig_send;	/* time of orginal send in useconds */
60 	uint32_t r_nseq_appl;	/* If this one is app limited, this is the nxt seq limited */
61 	uint32_t r_ack_arrival;	/* This is the time of ack-arrival (if SACK'd) */
62 	uint8_t r_dupack;	/* Dup ack count */
63 	uint8_t r_in_tmap;	/* Flag to see if its in the r_tnext array */
64 	uint8_t r_limit_type;	/* is this entry counted against a limit? */
65 	uint8_t r_just_ret : 1, /* After sending, the next pkt was just returned, i.e. limited  */
66 		r_one_out_nr : 1,	/* Special case 1 outstanding and not in recovery */
67 		r_avail : 6;
68 	uint8_t r_resv[36];
69 };
70 
71 RB_HEAD(rack_rb_tree_head, rack_sendmap);
72 TAILQ_HEAD(rack_head, rack_sendmap);
73 
74 #define RACK_LIMIT_TYPE_SPLIT	1
75 
76 /*
77  * We use the rate sample structure to
78  * assist in single sack/ack rate and rtt
79  * calculation. In the future we will expand
80  * this in BBR to do forward rate sample
81  * b/w estimation.
82  */
83 #define RACK_RTT_EMPTY 0x00000001	/* Nothing yet stored in RTT's */
84 #define RACK_RTT_VALID 0x00000002	/* We have at least one valid RTT */
85 struct rack_rtt_sample {
86 	uint32_t rs_flags;
87 	uint32_t rs_rtt_lowest;
88 	uint32_t rs_rtt_highest;
89 	uint32_t rs_rtt_cnt;
90 	uint32_t rs_us_rtt;
91 	int32_t  confidence;
92 	uint64_t rs_rtt_tot;
93 	uint16_t rs_us_rtrcnt;
94 };
95 
96 #define RACK_LOG_TYPE_ACK	0x01
97 #define RACK_LOG_TYPE_OUT	0x02
98 #define RACK_LOG_TYPE_TO	0x03
99 #define RACK_LOG_TYPE_ALLOC     0x04
100 #define RACK_LOG_TYPE_FREE      0x05
101 
102 
103 struct rack_log {
104 	union {
105 		struct rack_sendmap *rsm;	/* For alloc/free */
106 		uint64_t sb_acc;/* For out/ack or t-o */
107 	};
108 	uint32_t th_seq;
109 	uint32_t th_ack;
110 	uint32_t snd_una;
111 	uint32_t snd_nxt;	/* th_win for TYPE_ACK */
112 	uint32_t snd_max;
113 	uint32_t blk_start[4];
114 	uint32_t blk_end[4];
115 	uint8_t type;
116 	uint8_t n_sackblks;
117 	uint16_t len;		/* Timeout T3=1, TLP=2, RACK=3 */
118 };
119 
120 /*
121  * Magic numbers for logging timeout events if the
122  * logging is enabled.
123  */
124 #define RACK_TO_FRM_TMR  1
125 #define RACK_TO_FRM_TLP  2
126 #define RACK_TO_FRM_RACK 3
127 #define RACK_TO_FRM_KEEP 4
128 #define RACK_TO_FRM_PERSIST 5
129 #define RACK_TO_FRM_DELACK 6
130 
131 struct rack_opts_stats {
132 	uint64_t tcp_rack_prop_rate;
133  	uint64_t tcp_rack_prop;
134 	uint64_t tcp_rack_tlp_reduce;
135 	uint64_t tcp_rack_early_recov;
136 	uint64_t tcp_rack_pace_always;
137 	uint64_t tcp_rack_pace_reduce;
138 	uint64_t tcp_rack_max_seg;
139 	uint64_t tcp_rack_prr_sendalot;
140 	uint64_t tcp_rack_min_to;
141 	uint64_t tcp_rack_early_seg;
142 	uint64_t tcp_rack_reord_thresh;
143 	uint64_t tcp_rack_reord_fade;
144 	uint64_t tcp_rack_tlp_thresh;
145 	uint64_t tcp_rack_pkt_delay;
146 	uint64_t tcp_rack_tlp_inc_var;
147 	uint64_t tcp_tlp_use;
148 	uint64_t tcp_rack_idle_reduce;
149 	uint64_t tcp_rack_idle_reduce_high;
150 	uint64_t rack_no_timer_in_hpts;
151 	uint64_t tcp_rack_min_pace_seg;
152 	uint64_t tcp_rack_pace_rate_ca;
153 	uint64_t tcp_rack_rr;
154 	uint64_t tcp_rack_do_detection;
155 	uint64_t tcp_rack_rrr_no_conf_rate;
156 	uint64_t tcp_initial_rate;
157 	uint64_t tcp_initial_win;
158 	uint64_t tcp_hdwr_pacing;
159 	uint64_t tcp_gp_inc_ss;
160 	uint64_t tcp_gp_inc_ca;
161 	uint64_t tcp_gp_inc_rec;
162 	uint64_t tcp_rack_force_max_seg;
163 	uint64_t tcp_rack_pace_rate_ss;
164 	uint64_t tcp_rack_pace_rate_rec;
165 	/* Temp counters for dsack */
166 	uint64_t tcp_sack_path_1;
167 	uint64_t tcp_sack_path_2a;
168 	uint64_t tcp_sack_path_2b;
169 	uint64_t tcp_sack_path_3;
170 	uint64_t tcp_sack_path_4;
171 	/* non temp counters */
172 	uint64_t tcp_rack_scwnd;
173 	uint64_t tcp_rack_noprr;
174 	uint64_t tcp_rack_cfg_rate;
175 	uint64_t tcp_timely_dyn;
176 	uint64_t tcp_rack_mbufq;
177 	uint64_t tcp_fillcw;
178 	uint64_t tcp_npush;
179 	uint64_t tcp_lscwnd;
180 	uint64_t tcp_profile;
181 };
182 
183 /* RTT shrink reasons */
184 #define RACK_RTTS_INIT     0
185 #define RACK_RTTS_NEWRTT   1
186 #define RACK_RTTS_EXITPROBE 2
187 #define RACK_RTTS_ENTERPROBE 3
188 #define RACK_RTTS_REACHTARGET 4
189 #define RACK_RTTS_SEEHBP 5
190 #define RACK_RTTS_NOBACKOFF 6
191 #define RACK_RTTS_SAFETY 7
192 
193 #define RACK_USE_BEG 1
194 #define RACK_USE_END 2
195 #define RACK_USE_END_OR_THACK 3
196 
197 #define TLP_USE_ID	1	/* Internet draft behavior */
198 #define TLP_USE_TWO_ONE 2	/* Use 2.1 behavior */
199 #define TLP_USE_TWO_TWO 3	/* Use 2.2 behavior */
200 #define RACK_MIN_BW 8000	/* 64kbps in Bps */
201 
202 #define MIN_GP_WIN 6	/* We need at least 6 MSS in a GP measurement */
203 #ifdef _KERNEL
204 #define RACK_OPTS_SIZE (sizeof(struct rack_opts_stats)/sizeof(uint64_t))
205 extern counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
206 #define RACK_OPTS_ADD(name, amm) counter_u64_add(rack_opts_arry[(offsetof(struct rack_opts_stats, name)/sizeof(uint64_t))], (amm))
207 #define RACK_OPTS_INC(name) RACK_OPTS_ADD(name, 1)
208 #endif
209 /*
210  * As we get each SACK we wade through the
211  * rc_map and mark off what is acked.
212  * We also increment rc_sacked as well.
213  *
214  * We also pay attention to missing entries
215  * based on the time and possibly mark them
216  * for retransmit. If we do and we are not already
217  * in recovery we enter recovery. In doing
218  * so we claer prr_delivered/holes_rxt and prr_sent_dur_rec.
219  * We also setup rc_next/rc_snd_nxt/rc_send_end so
220  * we will know where to send from. When not in
221  * recovery rc_next will be NULL and rc_snd_nxt should
222  * equal snd_max.
223  *
224  * Whenever we retransmit from recovery we increment
225  * rc_holes_rxt as we retran a block and mark it as retransmitted
226  * with the time it was sent. During non-recovery sending we
227  * add to our map and note the time down of any send expanding
228  * the rc_map at the tail and moving rc_snd_nxt up with snd_max.
229  *
230  * In recovery during SACK/ACK processing if a chunk has
231  * been retransmitted and it is now acked, we decrement rc_holes_rxt.
232  * When we retransmit from the scoreboard we use
233  * rc_next and rc_snd_nxt/rc_send_end to help us
234  * find what needs to be retran.
235  *
236  * To calculate pipe we simply take (snd_max - snd_una) + rc_holes_rxt
237  * This gets us the effect of RFC6675 pipe, counting twice for
238  * bytes retransmitted.
239  */
240 
241 #define TT_RACK_FR_TMR	0x2000
242 
243 /*
244  * Locking for the rack control block.
245  * a) Locked by INP_WLOCK
246  * b) Locked by the hpts-mutex
247  *
248  */
249 #define RACK_GP_HIST 4	/* How much goodput history do we maintain? */
250 
251 struct rack_control {
252 	/* Second cache line 0x40 from tcp_rack */
253 	struct rack_rb_tree_head rc_mtree; /* Tree of all segments Lock(a) */
254 	struct rack_head rc_tmap;	/* List in transmit order Lock(a) */
255 	struct rack_sendmap *rc_tlpsend;	/* Remembered place for
256 						 * tlp_sending Lock(a) */
257 	struct rack_sendmap *rc_resend;	/* something we have been asked to
258 					 * resend */
259 	uint32_t input_pkt;
260 	uint32_t saved_input_pkt;
261 	uint32_t rc_hpts_flags;
262 	uint32_t rc_fixed_pacing_rate_ca;
263 	uint32_t rc_fixed_pacing_rate_rec;
264 	uint32_t rc_fixed_pacing_rate_ss;
265 	uint32_t cwnd_to_use;	/* The cwnd in use */
266 	uint32_t rc_timer_exp;	/* If a timer ticks of expiry */
267 	uint32_t rc_rack_min_rtt;	/* lowest RTT seen Lock(a) */
268 	uint32_t rc_rack_largest_cwnd;	/* Largest CWND we have seen Lock(a) */
269 
270 	/* Third Cache line 0x80 */
271 	struct rack_head rc_free;	/* Allocation array */
272 	uint32_t rc_time_last_sent;	/* Time we last sent some data and
273 					 * logged it Lock(a). */
274 	uint32_t rc_reorder_ts;	/* Last time we saw reordering Lock(a) */
275 
276 	uint32_t rc_tlp_new_data;	/* we need to send new-data on a TLP
277 					 * Lock(a) */
278 	uint32_t rc_prr_out;	/* bytes sent during recovery Lock(a) */
279 
280 	uint32_t rc_prr_recovery_fs;	/* recovery fs point Lock(a) */
281 
282 	uint32_t rc_prr_sndcnt;	/* Prr sndcnt Lock(a) */
283 
284 	uint32_t rc_sacked;	/* Tot sacked on scoreboard Lock(a) */
285 	uint32_t xxx_rc_last_tlp_seq;	/* Last tlp sequence Lock(a) */
286 
287 	uint32_t rc_prr_delivered;	/* during recovery prr var Lock(a) */
288 	uint16_t rc_tlp_cnt_out;	/* count of times we have sent a TLP without new data */
289 	uint16_t xxx_rc_tlp_seg_send_cnt;	/* Number of times we have TLP sent
290 					 * rc_last_tlp_seq Lock(a) */
291 
292 	uint32_t rc_loss_count;	/* How many bytes have been retransmitted
293 				 * Lock(a) */
294 	uint32_t rc_reorder_fade;	/* Socket option value Lock(a) */
295 
296 	/* Forth cache line 0xc0  */
297 	/* Times */
298 
299 	uint32_t rc_rack_tmit_time;	/* Rack transmit time Lock(a) */
300 	uint32_t rc_holes_rxt;	/* Tot retraned from scoreboard Lock(a) */
301 
302 	/* Variables to track bad retransmits and recover */
303 	uint32_t rc_rsm_start;	/* RSM seq number we retransmitted Lock(a) */
304 	uint32_t rc_cwnd_at;	/* cwnd at the retransmit Lock(a) */
305 
306 	uint32_t rc_ssthresh_at;/* ssthresh at the retransmit Lock(a) */
307 	uint32_t rc_num_maps_alloced;	/* Number of map blocks (sacks) we
308 					 * have allocated */
309 	uint32_t rc_rcvtime;	/* When we last received data */
310 	uint32_t rc_num_split_allocs;	/* num split map entries allocated */
311 
312 	uint32_t rc_last_output_to;
313 	uint32_t rc_went_idle_time;
314 
315 	struct rack_sendmap *rc_sacklast;	/* sack remembered place
316 						 * Lock(a) */
317 
318 	struct rack_sendmap *rc_rsm_at_retran;	/* Debug variable kept for
319 						 * cache line alignment
320 						 * Lock(a) */
321 	struct rack_sendmap *rc_first_appl;	/* Pointer to first app limited */
322 	struct rack_sendmap *rc_end_appl;	/* Pointer to last app limited */
323 	/* Cache line split 0x100 */
324 	struct sack_filter rack_sf;
325 	/* Cache line split 0x140 */
326 	/* Flags for various things */
327 	uint32_t last_pacing_time;
328 	uint32_t rc_pace_max_segs;
329 	uint32_t rc_pace_min_segs;
330 	uint32_t rc_app_limited_cnt;
331 	uint16_t rack_per_of_gp_ss; /* 100 = 100%, so from 65536 = 655 x bw  */
332 	uint16_t rack_per_of_gp_ca; /* 100 = 100%, so from 65536 = 655 x bw  */
333 	uint16_t rack_per_of_gp_rec; /* 100 = 100%, so from 65536 = 655 x bw, 0=off */
334 	uint16_t rack_per_of_gp_probertt; /* 100 = 100%, so from 65536 = 655 x bw, 0=off */
335 	uint32_t rc_high_rwnd;
336 	uint32_t ack_count;
337 	uint32_t sack_count;
338 	uint32_t sack_noextra_move;
339 	uint32_t sack_moved_extra;
340 	struct rack_rtt_sample rack_rs;
341 	const struct tcp_hwrate_limit_table *crte;
342 	uint32_t rc_agg_early;
343 	uint32_t rc_agg_delayed;
344 	uint32_t rc_tlp_rxt_last_time;
345 	uint32_t rc_saved_cwnd;
346 	uint32_t rc_gp_output_ts;
347 	uint32_t rc_gp_cumack_ts;
348 	struct timeval act_rcv_time;
349 	struct timeval rc_last_time_decay;	/* SAD time decay happened here */
350 	uint64_t gp_bw;
351 	uint64_t init_rate;
352 #ifdef NETFLIX_SHARED_CWND
353 	struct shared_cwnd *rc_scw;
354 #endif
355 	uint64_t last_gp_comp_bw;
356 	uint64_t last_max_bw;	/* Our calculated max b/w last */
357 	struct time_filter_small rc_gp_min_rtt;
358 	int32_t rc_rtt_diff;		/* Timely style rtt diff of our gp_srtt */
359 	uint32_t rc_gp_srtt;		/* Current GP srtt */
360 	uint32_t rc_prev_gp_srtt;	/* Previous RTT */
361 	uint32_t rc_entry_gp_rtt;	/* Entry to PRTT gp-rtt */
362 	uint32_t rc_loss_at_start;	/* At measurement window where was our lost value */
363 
364 	uint32_t forced_ack_ts;
365 	uint32_t rc_lower_rtt_us_cts;	/* Time our GP rtt was last lowered */
366 	uint32_t rc_time_probertt_entered;
367 	uint32_t rc_time_probertt_starts;
368 	uint32_t rc_lowest_us_rtt;
369 	uint32_t rc_highest_us_rtt;
370 	uint32_t rc_last_us_rtt;
371 	uint32_t rc_time_of_last_probertt;
372 	uint32_t rc_target_probertt_flight;
373 	uint32_t rc_probertt_sndmax_atexit;	/* Highest sent to in probe-rtt */
374 	uint32_t rc_gp_lowrtt;			/* Lowest rtt seen during GPUT measurement */
375 	uint32_t rc_gp_high_rwnd;		/* Highest rwnd seen during GPUT measurement */
376 	int32_t rc_scw_index;
377 	uint32_t rc_tlp_threshold;	/* Socket option value Lock(a) */
378 	uint16_t rc_early_recovery_segs;	/* Socket option value Lock(a) */
379 	uint16_t rc_reorder_shift;	/* Socket option value Lock(a) */
380 	uint16_t rc_pkt_delay;	/* Socket option value Lock(a) */
381 	uint8_t rc_no_push_at_mrtt;	/* No push when we exceed max rtt */
382 	uint8_t num_avg;	/* average count before we go to normal decay */
383 	uint8_t rc_prop_rate;	/* Socket option value Lock(a) */
384 	uint8_t rc_prop_reduce;	/* Socket option value Lock(a) */
385 	uint8_t rc_tlp_cwnd_reduce;	/* Socket option value Lock(a) */
386 	uint8_t rc_early_recovery;	/* Socket option value Lock(a) */
387 	uint8_t rc_prr_sendalot;/* Socket option value Lock(a) */
388 	uint8_t rc_min_to;	/* Socket option value Lock(a) */
389 	uint8_t rc_rate_sample_method;
390 	uint8_t rc_gp_hist_idx;
391 };
392 
393 #define RACK_TIMELY_CNT_BOOST 5	/* At 5th increase boost */
394 #define RACK_MINRTT_FILTER_TIM 10 /* Seconds */
395 
396 #ifdef _KERNEL
397 
398 struct tcp_rack {
399 	/* First cache line 0x00 */
400 	TAILQ_ENTRY(tcp_rack) r_hpts;	/* hptsi queue next Lock(b) */
401 	int32_t(*r_substate) (struct mbuf *, struct tcphdr *,
402 	    struct socket *, struct tcpcb *, struct tcpopt *,
403 	    int32_t, int32_t, uint32_t, int, int, uint8_t);	/* Lock(a) */
404 	struct tcpcb *rc_tp;	/* The tcpcb Lock(a) */
405 	struct inpcb *rc_inp;	/* The inpcb Lock(a) */
406 	uint32_t rc_free_cnt;	/* Number of free entries on the rc_free list
407 				 * Lock(a) */
408 	uint32_t rc_rack_rtt;	/* RACK-RTT Lock(a) */
409 	uint16_t r_mbuf_queue : 1,	/* Do we do mbuf queue for non-paced */
410 		 rtt_limit_mul : 4,	/* muliply this by low rtt */
411 		 r_limit_scw : 1,
412 		 r_avail_bits : 10;	/* Available */
413 
414 	uint16_t rc_user_set_max_segs;	/* Socket option value Lock(a) */
415 	uint16_t forced_ack : 1,
416 		rc_gp_incr : 1,
417 		rc_gp_bwred : 1,
418 		rc_gp_timely_inc_cnt : 3,
419 		rc_gp_timely_dec_cnt : 3,
420 		rc_not_backing_off: 1,
421 		rc_highly_buffered: 1,		/* The path is highly buffered */
422 		rc_dragged_bottom: 1,
423 		rc_dack_mode : 1,		/* Mac O/S emulation of d-ack */
424 		rc_dack_toggle : 1,		/* For Mac O/S emulation of d-ack */
425 		pacing_longer_than_rtt : 1,
426 		rc_gp_filled : 1;
427 	uint8_t r_state;	/* Current rack state Lock(a) */
428 	uint8_t rc_tmr_stopped : 7,
429 		t_timers_stopped : 1;
430 	uint8_t rc_enobuf : 7,	/* count of enobufs on connection provides */
431 		rc_on_min_to : 1;
432 	uint8_t r_timer_override : 1,	/* hpts override Lock(a) */
433 		r_is_v6 : 1,	/* V6 pcb Lock(a)  */
434 		rc_in_persist : 1,
435 		rc_tlp_in_progress : 1,
436 		rc_always_pace : 1,	/* Socket option value Lock(a) */
437 		rc_pace_to_cwnd : 1,
438 		rc_pace_fill_if_rttin_range : 1,
439 		xxx_avail_bits : 1;
440 	uint8_t app_limited_needs_set : 1,
441 		use_fixed_rate : 1,
442 		rc_has_collapsed : 1,
443 		r_rep_attack : 1,
444 		r_rep_reverse : 1,
445 		rack_hdrw_pacing : 1,  /* We are doing Hardware pacing */
446 		rack_hdw_pace_ena : 1, /* Is hardware pacing enabled? */
447 		rack_attempt_hdwr_pace : 1; /* Did we attempt hdwr pacing (if allowed) */
448 	uint8_t rack_tlp_threshold_use : 3,	/* only 1, 2 and 3 used so far */
449 		rack_rec_nonrxt_use_cr : 1,
450 		rack_enable_scwnd : 1,
451 		rack_attempted_scwnd : 1,
452 		rack_no_prr : 1,
453 		rack_scwnd_is_idle : 1;
454 	uint8_t rc_allow_data_af_clo: 1,
455 		delayed_ack : 1,
456 		set_pacing_done_a_iw : 1,
457 		use_rack_rr : 1,
458 		alloc_limit_reported : 1,
459 		sack_attack_disable : 1,
460 		do_detection : 1,
461 		rc_force_max_seg : 1;
462 	uint8_t rack_cwnd_limited : 1,
463 		r_early : 1,
464 		r_late : 1,
465 		r_running_early : 1,
466 		r_running_late : 1,
467 		r_wanted_output: 1,
468 		r_rr_config : 2;
469 	uint16_t rc_init_win : 8,
470 		rc_gp_rtt_set : 1,
471 		rc_gp_dyn_mul : 1,
472 		rc_gp_saw_rec : 1,
473 		rc_gp_saw_ca : 1,
474 		rc_gp_saw_ss : 1,
475 		rc_gp_no_rec_chg : 1,
476 		in_probe_rtt : 1,
477 		measure_saw_probe_rtt : 1;
478 	/* Cache line 2 0x40 */
479 	struct rack_control r_ctl;
480 }        __aligned(CACHE_LINE_SIZE);
481 
482 #endif
483 #endif
484