diff options
Diffstat (limited to 'sys/netinet/tcp_ratelimit.c')
| -rw-r--r-- | sys/netinet/tcp_ratelimit.c | 344 |
1 files changed, 309 insertions, 35 deletions
diff --git a/sys/netinet/tcp_ratelimit.c b/sys/netinet/tcp_ratelimit.c index 28f845221f28..6fcd97b9e1b8 100644 --- a/sys/netinet/tcp_ratelimit.c +++ b/sys/netinet/tcp_ratelimit.c @@ -66,45 +66,186 @@ __FBSDID("$FreeBSD$"); * For the purposes of each send, what is the size * of an ethernet frame. */ -#ifndef ETHERNET_SEGMENT_SIZE -#define ETHERNET_SEGMENT_SIZE 1500 -#endif MALLOC_DEFINE(M_TCPPACE, "tcp_hwpace", "TCP Hardware pacing memory"); #ifdef RATELIMIT +/* + * The following preferred table will seem weird to + * the casual viewer. Why do we not have any rates below + * 1Mbps? Why do we have a rate at 1.44Mbps called common? + * Why do the rates cluster in the 1-100Mbps range more + * than others? Why does the table jump around at the beginnign + * and then be more consistently raising? + * + * Let me try to answer those questions. A lot of + * this is dependant on the hardware. We have three basic + * supporters of rate limiting + * + * Chelsio - Supporting 16 configurable rates. + * Mlx - c4 supporting 13 fixed rates. + * Mlx - c5 & c6 supporting 127 configurable rates. + * + * The c4 is why we have a common rate that is available + * in all rate tables. This is a selected rate from the + * c4 table and we assure its available in all ratelimit + * tables. This way the tcp_ratelimit code has an assured + * rate it should always be able to get. This answers a + * couple of the questions above. + * + * So what about the rest, well the table is built to + * try to get the most out of a joint hardware/software + * pacing system. The software pacer will always pick + * a rate higher than the b/w that it is estimating + * + * on the path. This is done for two reasons. + * a) So we can discover more b/w + * and + * b) So we can send a block of MSS's down and then + * have the software timer go off after the previous + * send is completely out of the hardware. + * + * But when we do <b> we don't want to have the delay + * between the last packet sent by the hardware be + * excessively long (to reach our desired rate). + * + * So let me give an example for clarity. + * + * Lets assume that the tcp stack sees that 29,110,000 bps is + * what the bw of the path is. The stack would select the + * rate 31Mbps. 31Mbps means that each send that is done + * by the hardware will cause a 387 micro-second gap between + * the pacets sent at that rate. For 29,110,000 bps we + * would need 412 micro-seconds gap between each send. + * + * Now we pick a MSS size based on the delta between the + * two rates (412 - 387) divided into the rate we really + * wish to send at rounded up. That results in a MSS + * send of 17 mss's at once. The hardware then will + * run out of data in a single 17MSS send in 6,579 micro-seconds. + * On the other hand the software pacer will send more data + * in 7,004 micro-seconds. This means that we will refill + * the hardware 25 microseconds after it would have sent + * next. This is a win since we no are only sending every + * 7ms or so and yet all the packets are spaced on + * the wire with 94% of what they should be and only + * the last packet is delayed extra to make up for the + * difference. Note that the above formula has two + * important caveat. If we are above (b/w wise) over + * 100Mbps we double the result of the MSS calculation. + * The second caveat is if we are 500Mbps or more + * we just send the maximum MSS at once i.e. 45MSS + * + */ #define COMMON_RATE 180500 uint64_t desired_rates[] = { - 62500, /* 500Kbps */ - 180500, /* 1.44Mpbs */ - 375000, /* 3Mbps */ - 500000, /* 4Mbps */ - 625000, /* 5Mbps */ - 750000, /* 6Mbps */ - 1000000, /* 8Mbps */ - 1250000, /* 10Mbps */ - 2500000, /* 20Mbps */ - 3750000, /* 30Mbps */ - 5000000, /* 40Meg */ - 6250000, /* 50Mbps */ - 12500000, /* 100Mbps */ - 25000000, /* 200Mbps */ - 50000000, /* 400Mbps */ - 100000000, /* 800Mbps */ - 12500, /* 100kbps */ - 25000, /* 200kbps */ - 875000, /* 7Mbps */ - 1125000, /* 9Mbps */ - 1875000, /* 15Mbps */ - 3125000, /* 25Mbps */ - 8125000, /* 65Mbps */ - 10000000, /* 80Mbps */ - 18750000, /* 150Mbps */ - 20000000, /* 250Mbps */ - 37500000, /* 350Mbps */ - 62500000, /* 500Mbps */ - 78125000, /* 625Mbps */ - 125000000, /* 1Gbps */ + 122500, /* 1Mbps - rate 1 */ + 180500, /* 1.44Mpbs - rate 2 common rate */ + 375000, /* 3Mbps - rate 3 */ + 625000, /* 5Mbps - rate 4 */ + 875000, /* 7Mbps - rate 5 */ + 1125000, /* 9Mbps - rate 6 */ + 1375000, /* 11Mbps - rate 7 */ + 1625000, /* 13Mbps - rate 8 */ + 2625000, /* 21Mbps - rate 9 */ + 3875000, /* 31Mbps - rate 10 */ + 5125000, /* 41Meg - rate 11 */ + 12500000, /* 100Mbps - rate 12 */ + 25000000, /* 200Mbps - rate 13 */ + 50000000, /* 400Mbps - rate 14 */ + 63750000, /* 51Mbps - rate 15 */ + 100000000, /* 800Mbps - rate 16 */ + 1875000, /* 15Mbps - rate 17 */ + 2125000, /* 17Mbps - rate 18 */ + 2375000, /* 19Mbps - rate 19 */ + 2875000, /* 23Mbps - rate 20 */ + 3125000, /* 25Mbps - rate 21 */ + 3375000, /* 27Mbps - rate 22 */ + 3625000, /* 29Mbps - rate 23 */ + 4125000, /* 33Mbps - rate 24 */ + 4375000, /* 35Mbps - rate 25 */ + 4625000, /* 37Mbps - rate 26 */ + 4875000, /* 39Mbps - rate 27 */ + 5375000, /* 43Mbps - rate 28 */ + 5625000, /* 45Mbps - rate 29 */ + 5875000, /* 47Mbps - rate 30 */ + 6125000, /* 49Mbps - rate 31 */ + 6625000, /* 53Mbps - rate 32 */ + 6875000, /* 55Mbps - rate 33 */ + 7125000, /* 57Mbps - rate 34 */ + 7375000, /* 59Mbps - rate 35 */ + 7625000, /* 61Mbps - rate 36 */ + 7875000, /* 63Mbps - rate 37 */ + 8125000, /* 65Mbps - rate 38 */ + 8375000, /* 67Mbps - rate 39 */ + 8625000, /* 69Mbps - rate 40 */ + 8875000, /* 71Mbps - rate 41 */ + 9125000, /* 73Mbps - rate 42 */ + 9375000, /* 75Mbps - rate 43 */ + 9625000, /* 77Mbps - rate 44 */ + 9875000, /* 79Mbps - rate 45 */ + 10125000, /* 81Mbps - rate 46 */ + 10375000, /* 83Mbps - rate 47 */ + 10625000, /* 85Mbps - rate 48 */ + 10875000, /* 87Mbps - rate 49 */ + 11125000, /* 89Mbps - rate 50 */ + 11375000, /* 91Mbps - rate 51 */ + 11625000, /* 93Mbps - rate 52 */ + 11875000, /* 95Mbps - rate 53 */ + 13125000, /* 105Mbps - rate 54 */ + 13750000, /* 110Mbps - rate 55 */ + 14375000, /* 115Mbps - rate 56 */ + 15000000, /* 120Mbps - rate 57 */ + 15625000, /* 125Mbps - rate 58 */ + 16250000, /* 130Mbps - rate 59 */ + 16875000, /* 135Mbps - rate 60 */ + 17500000, /* 140Mbps - rate 61 */ + 18125000, /* 145Mbps - rate 62 */ + 18750000, /* 150Mbps - rate 64 */ + 20000000, /* 160Mbps - rate 65 */ + 21250000, /* 170Mbps - rate 66 */ + 22500000, /* 180Mbps - rate 67 */ + 23750000, /* 190Mbps - rate 68 */ + 26250000, /* 210Mbps - rate 69 */ + 27500000, /* 220Mbps - rate 70 */ + 28750000, /* 230Mbps - rate 71 */ + 30000000, /* 240Mbps - rate 72 */ + 31250000, /* 250Mbps - rate 73 */ + 34375000, /* 275Mbps - rate 74 */ + 37500000, /* 300Mbps - rate 75 */ + 40625000, /* 325Mbps - rate 76 */ + 43750000, /* 350Mbps - rate 77 */ + 46875000, /* 375Mbps - rate 78 */ + 53125000, /* 425Mbps - rate 79 */ + 56250000, /* 450Mbps - rate 80 */ + 59375000, /* 475Mbps - rate 81 */ + 62500000, /* 500Mbps - rate 82 */ + 68750000, /* 550Mbps - rate 83 */ + 75000000, /* 600Mbps - rate 84 */ + 81250000, /* 650Mbps - rate 85 */ + 87500000, /* 700Mbps - rate 86 */ + 93750000, /* 750Mbps - rate 87 */ + 106250000, /* 850Mbps - rate 88 */ + 112500000, /* 900Mbps - rate 89 */ + 125000000, /* 1Gbps - rate 90 */ + 156250000, /* 1.25Gps - rate 91 */ + 187500000, /* 1.5Gps - rate 92 */ + 218750000, /* 1.75Gps - rate 93 */ + 250000000, /* 2Gbps - rate 94 */ + 281250000, /* 2.25Gps - rate 95 */ + 312500000, /* 2.5Gbps - rate 96 */ + 343750000, /* 2.75Gbps - rate 97 */ + 375000000, /* 3Gbps - rate 98 */ + 500000000, /* 4Gbps - rate 99 */ + 625000000, /* 5Gbps - rate 100 */ + 750000000, /* 6Gbps - rate 101 */ + 875000000, /* 7Gbps - rate 102 */ + 1000000000, /* 8Gbps - rate 103 */ + 1125000000, /* 9Gbps - rate 104 */ + 1250000000, /* 10Gbps - rate 105 */ + 1875000000, /* 15Gbps - rate 106 */ + 2500000000 /* 20Gbps - rate 107 */ }; + #define MAX_HDWR_RATES (sizeof(desired_rates)/sizeof(uint64_t)) #define RS_ORDERED_COUNT 16 /* * Number that are in order @@ -381,16 +522,24 @@ rt_setup_new_rs(struct ifnet *ifp, int *error) * We can do nothing if we cannot * get a query back from the driver. */ + printf("No query functions for %s:%d-- failed\n", + ifp->if_dname, ifp->if_dunit); return (NULL); } rs = malloc(sizeof(struct tcp_rate_set), M_TCPPACE, M_NOWAIT | M_ZERO); if (rs == NULL) { if (error) *error = ENOMEM; + printf("No memory for malloc\n"); return (NULL); } + memset(&rl, 0, sizeof(rl)); rl.flags = RT_NOSUPPORT; ifp->if_ratelimit_query(ifp, &rl); + printf("if:%s:%d responds with flags:0x%x rate count:%d\n", + ifp->if_dname, + ifp->if_dunit, + rl.flags, rl.number_of_rates); if (rl.flags & RT_IS_UNUSABLE) { /* * The interface does not really support @@ -433,7 +582,7 @@ rt_setup_new_rs(struct ifnet *ifp, int *error) mtx_unlock(&rs_mtx); return (rs); } else if ((rl.flags & RT_IS_FIXED_TABLE) == RT_IS_FIXED_TABLE) { - /* Mellanox most likely */ + /* Mellanox C4 likely */ rs->rs_ifp = ifp; rs->rs_if_dunit = ifp->if_dunit; rs->rs_rate_cnt = rl.number_of_rates; @@ -444,7 +593,7 @@ rt_setup_new_rs(struct ifnet *ifp, int *error) rs->rs_disable = 0; rate_table_act = rl.rate_table; } else if ((rl.flags & RT_IS_SELECTABLE) == RT_IS_SELECTABLE) { - /* Chelsio */ + /* Chelsio, C5 and C6 of Mellanox? */ rs->rs_ifp = ifp; rs->rs_if_dunit = ifp->if_dunit; rs->rs_rate_cnt = rl.number_of_rates; @@ -536,6 +685,14 @@ bail: rs->rs_lowest_valid = i; } else { int err; + + if ((rl.flags & RT_IS_SETUP_REQ) && + (ifp->if_ratelimit_query)) { + err = ifp->if_ratelimit_setup(ifp, + rs->rs_rlt[i].rate, i); + if (err) + goto handle_err; + } #ifdef RSS hash_type = M_HASHTYPE_RSS_TCP_IPV4; #else @@ -547,6 +704,7 @@ bail: rs->rs_rlt[i].rate, &rs->rs_rlt[i].tag); if (err) { +handle_err: if (i == (rs->rs_rate_cnt - 1)) { /* * Huh - first rate and we can't get @@ -980,13 +1138,22 @@ tcp_rl_ifnet_link(void *arg __unused, struct ifnet *ifp, int link_state) * We only care on an interface going up that is rate-limit * capable. */ + printf("ifp:%s.%d does not support rate-limit(0x%x) or link_state is not UP(state:%d)\n", + ifp->if_dname, + ifp->if_dunit, + ifp->if_capabilities, + link_state); return; } mtx_lock(&rs_mtx); + printf("Link UP on interface %s.%d\n", + ifp->if_dname, + ifp->if_dunit); CK_LIST_FOREACH(rs, &int_rs, next) { if ((rs->rs_ifp == ifp) && (rs->rs_if_dunit == ifp->if_dunit)) { /* We already have initialized this guy */ + printf("Interface already initialized\n"); mtx_unlock(&rs_mtx); return; } @@ -1087,6 +1254,7 @@ tcp_set_pacing_rate(struct tcpcb *tp, struct ifnet *ifp, *error = EINVAL; rte = NULL; } + *error = 0; return (rte); } @@ -1196,6 +1364,112 @@ tcp_rel_pacing_rate(const struct tcp_hwrate_limit_table *crte, struct tcpcb *tp) in_pcbdetach_txrtlmt(tp->t_inpcb); } +#define ONE_POINT_TWO_MEG 150000 /* 1.2 megabits in bytes */ +#define ONE_HUNDRED_MBPS 12500000 /* 100Mbps in bytes per second */ +#define FIVE_HUNDRED_MBPS 62500000 /* 500Mbps in bytes per second */ +#define MAX_MSS_SENT 43 /* 43 mss = 43 x 1500 = 64,500 bytes */ + +uint32_t +tcp_get_pacing_mss(uint64_t bw, uint32_t segsiz, int can_use_1mss, + const struct tcp_hwrate_limit_table *te) +{ + /* + * We use the google formula to calculate the + * TSO size. I.E. + * bw < 24Meg + * tso = 2mss + * else + * tso = min(bw/1000, 64k) + * + * Note for these calculations we ignore the + * packet overhead (enet hdr, ip hdr and tcp hdr). + */ + uint64_t lentim, res, bytes; + uint32_t new_tso, min_tso_segs; + + bytes = bw / 1000; + if (bytes > (64 * 1000)) + bytes = 64 * 1000; + /* Round up */ + new_tso = (bytes + segsiz - 1) / segsiz; + if (can_use_1mss && (bw < ONE_POINT_TWO_MEG)) + min_tso_segs = 1; + else + min_tso_segs = 2; + if (new_tso < min_tso_segs) + new_tso = min_tso_segs; + if (new_tso > MAX_MSS_SENT) + new_tso = MAX_MSS_SENT; + new_tso *= segsiz; + /* + * If we are not doing hardware pacing + * then we are done. + */ + if (te == NULL) + return(new_tso); + /* + * For hardware pacing we look at the + * rate you are sending at and compare + * that to the rate you have in hardware. + * + * If the hardware rate is slower than your + * software rate then you are in error and + * we will build a queue in our hardware whic + * is probably not desired, in such a case + * just return the non-hardware TSO size. + * + * If the rate in hardware is faster (which + * it should be) then look at how long it + * takes to send one ethernet segment size at + * your b/w and compare that to the time it + * takes to send at the rate you had selected. + * + * If your time is greater (which we hope it is) + * we get the delta between the two, and then + * divide that into your pacing time. This tells + * us how many MSS you can send down at once (rounded up). + * + * Note we also double this value if the b/w is over + * 100Mbps. If its over 500meg we just set you to the + * max (43 segments). + */ + if (te->rate > FIVE_HUNDRED_MBPS) + return (segsiz * MAX_MSS_SENT); + if (te->rate == bw) { + /* We are pacing at exactly the hdwr rate */ + return (segsiz * MAX_MSS_SENT); + } + lentim = ETHERNET_SEGMENT_SIZE * USECS_IN_SECOND; + res = lentim / bw; + if (res > te->time_between) { + uint32_t delta, segs; + + delta = res - te->time_between; + segs = (res + delta - 1)/delta; + if (te->rate > ONE_HUNDRED_MBPS) + segs *= 2; + if (segs < min_tso_segs) + segs = min_tso_segs; + if (segs > MAX_MSS_SENT) + segs = MAX_MSS_SENT; + segs *= segsiz; + if (segs < new_tso) { + /* unexpected ? */ + return(new_tso); + } else { + return (segs); + } + } else { + /* + * Your time is smaller which means + * we will grow a queue on our + * hardware. Send back the non-hardware + * rate. + */ + return (new_tso); + } +} + static eventhandler_tag rl_ifnet_departs; static eventhandler_tag rl_ifnet_arrives; static eventhandler_tag rl_shutdown_start; |