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Commit 0760b8e4 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by David S. Miller
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[PKT_SCHED]: Add jitter support to netem. 

This patch adds jitter if desired to the delayed packets in the
netem scheduler.  I dropped the rate stuff out and reorganized so
that an underlying pfifo queue is used (next plan is to make it
have class ops).

The jitter is given as sigma to a Gaussian normal distribution.  The actual
implementation is a reduced form of the table driven stuff in NISTnet
(free).
Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@redhat.com>
parent ca4d1264
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Showing with 677 additions and 75 deletions
include/linux/pkt_sched.h
View file @ 0760b8e4
......@@ -409,6 +409,6 @@ struct tc_netem_qopt
__u32 loss; /* random packet loss (0=none ~0=100%) */
__u32 gap; /* re-ordering gap (0 for delay all) */
__u32 duplicate; /* random packet dup (0=none ~0=100%) */
__u32 rate; /* maximum transmit rate (bytes/sec) */
__u32 jitter; /* random jitter in latency (us) */
};
#endif
net/sched/sch_netem.c
View file @ 0760b8e4
......@@ -29,14 +29,16 @@
*/
struct netem_sched_data {
struct sk_buff_head qnormal;
struct sk_buff_head qdelay;
struct Qdisc *qdisc;
struct sk_buff_head delayed;
struct timer_list timer;
u32 latency;
u32 loss;
u32 limit;
u32 counter;
u32 gap;
u32 jitter;
};
/* Time stamp put into socket buffer control block */
......@@ -44,6 +46,558 @@ struct netem_skb_cb {
psched_time_t time_to_send;
};
/* This is the distribution table for the normal distribution produced
* with NISTnet tools.
* The entries represent a scaled inverse of the cumulative distribution
* function.
*/
#define TABLESIZE 2048
#define TABLEFACTOR 8192
static const short disttable[TABLESIZE] = {
-31473, -26739, -25226, -24269,
-23560, -22993, -22518, -22109,
-21749, -21426, -21133, -20865,
-20618, -20389, -20174, -19972,
-19782, -19601, -19430, -19267,
-19112, -18962, -18819, -18681,
-18549, -18421, -18298, -18178,
-18062, -17950, -17841, -17735,
-17632, -17532, -17434, -17339,
-17245, -17155, -17066, -16979,
-16894, -16811, -16729, -16649,
-16571, -16494, -16419, -16345,
-16272, -16201, -16130, -16061,
-15993, -15926, -15861, -15796,
-15732, -15669, -15607, -15546,
-15486, -15426, -15368, -15310,
-15253, -15196, -15140, -15086,
-15031, -14977, -14925, -14872,
-14821, -14769, -14719, -14669,
-14619, -14570, -14522, -14473,
-14426, -14379, -14332, -14286,
-14241, -14196, -14150, -14106,
-14062, -14019, -13976, -13933,
-13890, -13848, -13807, -13765,
-13724, -13684, -13643, -13604,
-13564, -13525, -13486, -13447,
-13408, -13370, -13332, -13295,
-13258, -13221, -13184, -13147,
-13111, -13075, -13040, -13004,
-12969, -12934, -12899, -12865,
-12830, -12796, -12762, -12729,
-12695, -12662, -12629, -12596,
-12564, -12531, -12499, -12467,
-12435, -12404, -12372, -12341,
-12310, -12279, -12248, -12218,
-12187, -12157, -12127, -12097,
-12067, -12038, -12008, -11979,
-11950, -11921, -11892, -11863,
-11835, -11806, -11778, -11750,
-11722, -11694, -11666, -11639,
-11611, -11584, -11557, -11530,
-11503, -11476, -11450, -11423,
-11396, -11370, -11344, -11318,
-11292, -11266, -11240, -11214,
-11189, -11164, -11138, -11113,
-11088, -11063, -11038, -11013,
-10988, -10964, -10939, -10915,
-10891, -10866, -10843, -10818,
-10794, -10770, -10747, -10723,
-10700, -10676, -10652, -10630,
-10606, -10583, -10560, -10537,
-10514, -10491, -10469, -10446,
-10424, -10401, -10378, -10356,
-10334, -10312, -10290, -10267,
-10246, -10224, -10202, -10180,
-10158, -10137, -10115, -10094,
-10072, -10051, -10030, -10009,
-9988, -9967, -9945, -9925,
-9904, -9883, -9862, -9842,
-9821, -9800, -9780, -9760,
-9739, -9719, -9699, -9678,
-9658, -9638, -9618, -9599,
-9578, -9559, -9539, -9519,
-9499, -9480, -9461, -9441,
-9422, -9402, -9383, -9363,
-9344, -9325, -9306, -9287,
-9268, -9249, -9230, -9211,
-9192, -9173, -9155, -9136,
-9117, -9098, -9080, -9062,
-9043, -9025, -9006, -8988,
-8970, -8951, -8933, -8915,
-8897, -8879, -8861, -8843,
-8825, -8807, -8789, -8772,
-8754, -8736, -8718, -8701,
-8683, -8665, -8648, -8630,
-8613, -8595, -8578, -8561,
-8543, -8526, -8509, -8492,
-8475, -8458, -8441, -8423,
-8407, -8390, -8373, -8356,
-8339, -8322, -8305, -8289,
-8272, -8255, -8239, -8222,
-8206, -8189, -8172, -8156,
-8140, -8123, -8107, -8090,
-8074, -8058, -8042, -8025,
-8009, -7993, -7977, -7961,
-7945, -7929, -7913, -7897,
-7881, -7865, -7849, -7833,
-7817, -7802, -7786, -7770,
-7754, -7739, -7723, -7707,
-7692, -7676, -7661, -7645,
-7630, -7614, -7599, -7583,
-7568, -7553, -7537, -7522,
-7507, -7492, -7476, -7461,
-7446, -7431, -7416, -7401,
-7385, -7370, -7356, -7340,
-7325, -7311, -7296, -7281,
-7266, -7251, -7236, -7221,
-7207, -7192, -7177, -7162,
-7148, -7133, -7118, -7104,
-7089, -7075, -7060, -7046,
-7031, -7016, -7002, -6988,
-6973, -6959, -6944, -6930,
-6916, -6901, -6887, -6873,
-6859, -6844, -6830, -6816,
-6802, -6788, -6774, -6760,
-6746, -6731, -6717, -6704,
-6690, -6675, -6661, -6647,
-6633, -6620, -6606, -6592,
-6578, -6564, -6550, -6537,
-6523, -6509, -6495, -6482,
-6468, -6454, -6441, -6427,
-6413, -6400, -6386, -6373,
-6359, -6346, -6332, -6318,
-6305, -6291, -6278, -6264,
-6251, -6238, -6224, -6211,
-6198, -6184, -6171, -6158,
-6144, -6131, -6118, -6105,
-6091, -6078, -6065, -6052,
-6039, -6025, -6012, -5999,
-5986, -5973, -5960, -5947,
-5934, -5921, -5908, -5895,
-5882, -5869, -5856, -5843,
-5830, -5817, -5804, -5791,
-5779, -5766, -5753, -5740,
-5727, -5714, -5702, -5689,
-5676, -5663, -5650, -5638,
-5625, -5612, -5600, -5587,
-5575, -5562, -5549, -5537,
-5524, -5512, -5499, -5486,
-5474, -5461, -5449, -5436,
-5424, -5411, -5399, -5386,
-5374, -5362, -5349, -5337,
-5324, -5312, -5299, -5287,
-5275, -5263, -5250, -5238,
-5226, -5213, -5201, -5189,
-5177, -5164, -5152, -5140,
-5128, -5115, -5103, -5091,
-5079, -5067, -5055, -5043,
-5030, -5018, -5006, -4994,
-4982, -4970, -4958, -4946,
-4934, -4922, -4910, -4898,
-4886, -4874, -4862, -4850,
-4838, -4826, -4814, -4803,
-4791, -4778, -4767, -4755,
-4743, -4731, -4719, -4708,
-4696, -4684, -4672, -4660,
-4649, -4637, -4625, -4613,
-4601, -4590, -4578, -4566,
-4554, -4543, -4531, -4520,
-4508, -4496, -4484, -4473,
-4461, -4449, -4438, -4427,
-4415, -4403, -4392, -4380,
-4368, -4357, -4345, -4334,
-4322, -4311, -4299, -4288,
-4276, -4265, -4253, -4242,
-4230, -4219, -4207, -4196,
-4184, -4173, -4162, -4150,
-4139, -4128, -4116, -4105,
-4094, -4082, -4071, -4060,
-4048, -4037, -4026, -4014,
-4003, -3992, -3980, -3969,
-3958, -3946, -3935, -3924,
-3913, -3901, -3890, -3879,
-3868, -3857, -3845, -3834,
-3823, -3812, -3801, -3790,
-3779, -3767, -3756, -3745,
-3734, -3723, -3712, -3700,
-3689, -3678, -3667, -3656,
-3645, -3634, -3623, -3612,
-3601, -3590, -3579, -3568,
-3557, -3545, -3535, -3524,
-3513, -3502, -3491, -3480,
-3469, -3458, -3447, -3436,
-3425, -3414, -3403, -3392,
-3381, -3370, -3360, -3348,
-3337, -3327, -3316, -3305,
-3294, -3283, -3272, -3262,
-3251, -3240, -3229, -3218,
-3207, -3197, -3185, -3175,
-3164, -3153, -3142, -3132,
-3121, -3110, -3099, -3088,
-3078, -3067, -3056, -3045,
-3035, -3024, -3013, -3003,
-2992, -2981, -2970, -2960,
-2949, -2938, -2928, -2917,
-2906, -2895, -2885, -2874,
-2864, -2853, -2842, -2832,
-2821, -2810, -2800, -2789,
-2778, -2768, -2757, -2747,
-2736, -2725, -2715, -2704,
-2694, -2683, -2673, -2662,
-2651, -2641, -2630, -2620,
-2609, -2599, -2588, -2578,
-2567, -2556, -2546, -2535,
-2525, -2515, -2504, -2493,
-2483, -2472, -2462, -2451,
-2441, -2431, -2420, -2410,
-2399, -2389, -2378, -2367,
-2357, -2347, -2336, -2326,
-2315, -2305, -2295, -2284,
-2274, -2263, -2253, -2243,
-2232, -2222, -2211, -2201,
-2191, -2180, -2170, -2159,
-2149, -2139, -2128, -2118,
-2107, -2097, -2087, -2076,
-2066, -2056, -2046, -2035,
-2025, -2014, -2004, -1994,
-1983, -1973, -1963, -1953,
-1942, -1932, -1921, -1911,
-1901, -1891, -1880, -1870,
-1860, -1849, -1839, -1829,
-1819, -1808, -1798, -1788,
-1778, -1767, -1757, -1747,
-1736, -1726, -1716, -1706,
-1695, -1685, -1675, -1665,
-1654, -1644, -1634, -1624,
-1613, -1603, -1593, -1583,
-1573, -1563, -1552, -1542,
-1532, -1522, -1511, -1501,
-1491, -1481, -1471, -1461,
-1450, -1440, -1430, -1420,
-1409, -1400, -1389, -1379,
-1369, -1359, -1348, -1339,
-1328, -1318, -1308, -1298,
-1288, -1278, -1267, -1257,
-1247, -1237, -1227, -1217,
-1207, -1196, -1186, -1176,
-1166, -1156, -1146, -1135,
-1126, -1115, -1105, -1095,
-1085, -1075, -1065, -1055,
-1044, -1034, -1024, -1014,
-1004, -994, -984, -974,
-964, -954, -944, -933,
-923, -913, -903, -893,
-883, -873, -863, -853,
-843, -833, -822, -812,
-802, -792, -782, -772,
-762, -752, -742, -732,
-722, -712, -702, -691,
-682, -671, -662, -651,
-641, -631, -621, -611,
-601, -591, -581, -571,
-561, -551, -541, -531,
-521, -511, -501, -491,
-480, -471, -460, -451,
-440, -430, -420, -410,
-400, -390, -380, -370,
-360, -350, -340, -330,
-320, -310, -300, -290,
-280, -270, -260, -250,
-240, -230, -220, -210,
-199, -190, -179, -170,
-159, -150, -139, -129,
-119, -109, -99, -89,
-79, -69, -59, -49,
-39, -29, -19, -9,
1, 11, 21, 31,
41, 51, 61, 71,
81, 91, 101, 111,
121, 131, 141, 152,
161, 172, 181, 192,
202, 212, 222, 232,
242, 252, 262, 272,
282, 292, 302, 312,
322, 332, 342, 352,
362, 372, 382, 392,
402, 412, 422, 433,
442, 453, 462, 473,
483, 493, 503, 513,
523, 533, 543, 553,
563, 573, 583, 593,
603, 613, 623, 633,
643, 653, 664, 673,
684, 694, 704, 714,
724, 734, 744, 754,
764, 774, 784, 794,
804, 815, 825, 835,
845, 855, 865, 875,
885, 895, 905, 915,
925, 936, 946, 956,
966, 976, 986, 996,
1006, 1016, 1026, 1037,
1047, 1057, 1067, 1077,
1087, 1097, 1107, 1117,
1128, 1138, 1148, 1158,
1168, 1178, 1188, 1198,
1209, 1219, 1229, 1239,
1249, 1259, 1269, 1280,
1290, 1300, 1310, 1320,
1330, 1341, 1351, 1361,
1371, 1381, 1391, 1402,
1412, 1422, 1432, 1442,
1452, 1463, 1473, 1483,
1493, 1503, 1513, 1524,
1534, 1544, 1554, 1565,
1575, 1585, 1595, 1606,
1616, 1626, 1636, 1647,
1656, 1667, 1677, 1687,
1697, 1708, 1718, 1729,
1739, 1749, 1759, 1769,
1780, 1790, 1800, 1810,
1821, 1831, 1841, 1851,
1862, 1872, 1883, 1893,
1903, 1913, 1923, 1934,
1944, 1955, 1965, 1975,
1985, 1996, 2006, 2016,
2027, 2037, 2048, 2058,
2068, 2079, 2089, 2099,
2110, 2120, 2130, 2141,
2151, 2161, 2172, 2182,
2193, 2203, 2213, 2224,
2234, 2245, 2255, 2265,
2276, 2286, 2297, 2307,
2318, 2328, 2338, 2349,
2359, 2370, 2380, 2391,
2401, 2412, 2422, 2433,
2443, 2454, 2464, 2475,
2485, 2496, 2506, 2517,
2527, 2537, 2548, 2559,
2569, 2580, 2590, 2601,
2612, 2622, 2632, 2643,
2654, 2664, 2675, 2685,
2696, 2707, 2717, 2728,
2738, 2749, 2759, 2770,
2781, 2791, 2802, 2813,
2823, 2834, 2845, 2855,
2866, 2877, 2887, 2898,
2909, 2919, 2930, 2941,
2951, 2962, 2973, 2984,
2994, 3005, 3015, 3027,
3037, 3048, 3058, 3069,
3080, 3091, 3101, 3113,
3123, 3134, 3145, 3156,
3166, 3177, 3188, 3199,
3210, 3220, 3231, 3242,
3253, 3264, 3275, 3285,
3296, 3307, 3318, 3329,
3340, 3351, 3362, 3373,
3384, 3394, 3405, 3416,
3427, 3438, 3449, 3460,
3471, 3482, 3493, 3504,
3515, 3526, 3537, 3548,
3559, 3570, 3581, 3592,
3603, 3614, 3625, 3636,
3647, 3659, 3670, 3681,
3692, 3703, 3714, 3725,
3736, 3747, 3758, 3770,
3781, 3792, 3803, 3814,
3825, 3837, 3848, 3859,
3870, 3881, 3893, 3904,
3915, 3926, 3937, 3949,
3960, 3971, 3983, 3994,
4005, 4017, 4028, 4039,
4051, 4062, 4073, 4085,
4096, 4107, 4119, 4130,
4141, 4153, 4164, 4175,
4187, 4198, 4210, 4221,
4233, 4244, 4256, 4267,
4279, 4290, 4302, 4313,
4325, 4336, 4348, 4359,
4371, 4382, 4394, 4406,
4417, 4429, 4440, 4452,
4464, 4475, 4487, 4499,
4510, 4522, 4533, 4545,
4557, 4569, 4581, 4592,
4604, 4616, 4627, 4639,
4651, 4663, 4674, 4686,
4698, 4710, 4722, 4734,
4746, 4758, 4769, 4781,
4793, 4805, 4817, 4829,
4841, 4853, 4865, 4877,
4889, 4900, 4913, 4925,
4936, 4949, 4961, 4973,
4985, 4997, 5009, 5021,
5033, 5045, 5057, 5070,
5081, 5094, 5106, 5118,
5130, 5143, 5155, 5167,
5179, 5191, 5204, 5216,
5228, 5240, 5253, 5265,
5278, 5290, 5302, 5315,
5327, 5340, 5352, 5364,
5377, 5389, 5401, 5414,
5426, 5439, 5451, 5464,
5476, 5489, 5502, 5514,
5527, 5539, 5552, 5564,
5577, 5590, 5603, 5615,
5628, 5641, 5653, 5666,
5679, 5691, 5704, 5717,
5730, 5743, 5756, 5768,
5781, 5794, 5807, 5820,
5833, 5846, 5859, 5872,
5885, 5897, 5911, 5924,
5937, 5950, 5963, 5976,
5989, 6002, 6015, 6028,
6042, 6055, 6068, 6081,
6094, 6108, 6121, 6134,
6147, 6160, 6174, 6187,
6201, 6214, 6227, 6241,
6254, 6267, 6281, 6294,
6308, 6321, 6335, 6348,
6362, 6375, 6389, 6403,
6416, 6430, 6443, 6457,
6471, 6485, 6498, 6512,
6526, 6540, 6554, 6567,
6581, 6595, 6609, 6623,
6637, 6651, 6665, 6679,
6692, 6706, 6721, 6735,
6749, 6763, 6777, 6791,
6805, 6819, 6833, 6848,
6862, 6876, 6890, 6905,
6919, 6933, 6948, 6962,
6976, 6991, 7005, 7020,
7034, 7049, 7064, 7078,
7093, 7107, 7122, 7136,
7151, 7166, 7180, 7195,
7210, 7225, 7240, 7254,
7269, 7284, 7299, 7314,
7329, 7344, 7359, 7374,
7389, 7404, 7419, 7434,
7449, 7465, 7480, 7495,
7510, 7526, 7541, 7556,
7571, 7587, 7602, 7618,
7633, 7648, 7664, 7680,
7695, 7711, 7726, 7742,
7758, 7773, 7789, 7805,
7821, 7836, 7852, 7868,
7884, 7900, 7916, 7932,
7948, 7964, 7981, 7997,
8013, 8029, 8045, 8061,
8078, 8094, 8110, 8127,
8143, 8160, 8176, 8193,
8209, 8226, 8242, 8259,
8276, 8292, 8309, 8326,
8343, 8360, 8377, 8394,
8410, 8428, 8444, 8462,
8479, 8496, 8513, 8530,
8548, 8565, 8582, 8600,
8617, 8634, 8652, 8670,
8687, 8704, 8722, 8740,
8758, 8775, 8793, 8811,
8829, 8847, 8865, 8883,
8901, 8919, 8937, 8955,
8974, 8992, 9010, 9029,
9047, 9066, 9084, 9103,
9121, 9140, 9159, 9177,
9196, 9215, 9234, 9253,
9272, 9291, 9310, 9329,
9349, 9368, 9387, 9406,
9426, 9445, 9465, 9484,
9504, 9524, 9544, 9563,
9583, 9603, 9623, 9643,
9663, 9683, 9703, 9723,
9744, 9764, 9785, 9805,
9826, 9846, 9867, 9888,
9909, 9930, 9950, 9971,
9993, 10013, 10035, 10056,
10077, 10099, 10120, 10142,
10163, 10185, 10207, 10229,
10251, 10273, 10294, 10317,
10339, 10361, 10384, 10406,
10428, 10451, 10474, 10496,
10519, 10542, 10565, 10588,
10612, 10635, 10658, 10682,
10705, 10729, 10752, 10776,
10800, 10824, 10848, 10872,
10896, 10921, 10945, 10969,
10994, 11019, 11044, 11069,
11094, 11119, 11144, 11169,
11195, 11221, 11246, 11272,
11298, 11324, 11350, 11376,
11402, 11429, 11456, 11482,
11509, 11536, 11563, 11590,
11618, 11645, 11673, 11701,
11728, 11756, 11785, 11813,
11842, 11870, 11899, 11928,
11957, 11986, 12015, 12045,
12074, 12104, 12134, 12164,
12194, 12225, 12255, 12286,
12317, 12348, 12380, 12411,
12443, 12475, 12507, 12539,
12571, 12604, 12637, 12670,
12703, 12737, 12771, 12804,
12839, 12873, 12907, 12942,
12977, 13013, 13048, 13084,
13120, 13156, 13192, 13229,
13267, 13304, 13341, 13379,
13418, 13456, 13495, 13534,
13573, 13613, 13653, 13693,
13734, 13775, 13817, 13858,
13901, 13943, 13986, 14029,
14073, 14117, 14162, 14206,
14252, 14297, 14343, 14390,
14437, 14485, 14533, 14582,
14631, 14680, 14731, 14782,
14833, 14885, 14937, 14991,
15044, 15099, 15154, 15210,
15266, 15324, 15382, 15441,
15500, 15561, 15622, 15684,
15747, 15811, 15877, 15943,
16010, 16078, 16148, 16218,
16290, 16363, 16437, 16513,
16590, 16669, 16749, 16831,
16915, 17000, 17088, 17177,
17268, 17362, 17458, 17556,
17657, 17761, 17868, 17977,
18090, 18207, 18328, 18452,
18581, 18715, 18854, 18998,
19149, 19307, 19472, 19645,
19828, 20021, 20226, 20444,
20678, 20930, 21204, 21503,
21835, 22206, 22630, 23124,
23721, 24478, 25529, 27316,
};
/* tabledist - return a pseudo-randomly distributed value with mean mu and
* std deviation sigma. Uses table lookup to approximate the desired
* distribution, and a uniformly-distributed pseudo-random source.
*/
static inline int tabledist(int mu, int sigma)
{
int x;
int index;
int sigmamod, sigmadiv;
if (sigma == 0)
return mu;
index = (net_random() & (TABLESIZE-1));
sigmamod = sigma%TABLEFACTOR;
sigmadiv = sigma/TABLEFACTOR;
x = sigmamod*disttable[index];
if (x >= 0)
x += TABLEFACTOR/2;
else
x -= TABLEFACTOR/2;
x /= TABLEFACTOR;
x += sigmadiv*disttable[index];
x += mu;
return x;
}
/* Enqueue packets with underlying discipline (fifo)
* but mark them with current time first.
*/
......@@ -51,6 +605,8 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
psched_time_t now;
long delay;
pr_debug("netem_enqueue skb=%p @%lu\n", skb, jiffies);
......@@ -60,101 +616,105 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
return 0; /* lie about loss so TCP doesn't know */
}
if (q->qnormal.qlen < sch->dev->tx_queue_len) {
PSCHED_GET_TIME(cb->time_to_send);
PSCHED_TADD(cb->time_to_send, q->latency);
__skb_queue_tail(&q->qnormal, skb);
sch->q.qlen++;
sch->stats.bytes += skb->len;
sch->stats.packets++;
return 0;
}
/* If doing simple delay then gap == 0 so all packets
* go into the delayed holding queue
* otherwise if doing out of order only "1 out of gap"
* packets will be delayed.
*/
if (q->counter < q->gap) {
int ret;
sch->stats.drops++;
kfree_skb(skb);
return NET_XMIT_DROP;
++q->counter;
ret = q->qdisc->enqueue(skb, q->qdisc);
if (ret)
sch->stats.drops++;
return ret;
}
q->counter = 0;
PSCHED_GET_TIME(now);
if (q->jitter)
delay = tabledist(q->latency, q->jitter);
else
delay = q->latency;
PSCHED_TADD2(now, delay, cb->time_to_send);
/* Always queue at tail to keep packets in order */
__skb_queue_tail(&q->delayed, skb);
sch->q.qlen++;
sch->stats.bytes += skb->len;
sch->stats.packets++;
return 0;
}
/* Requeue packets but don't change time stamp */
static int netem_requeue(struct sk_buff *skb, struct Qdisc *sch)
{
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
int ret;
__skb_queue_head(&q->qnormal, skb);
sch->q.qlen++;
return 0;
if ((ret = q->qdisc->ops->requeue(skb, q->qdisc)) == 0)
sch->q.qlen++;
return ret;
}
/*
* Check the look aside buffer list, and see if any freshly baked buffers.
* If head of queue is not baked, set timer.
*/
static struct sk_buff *netem_get_delayed(struct netem_sched_data *q)
static unsigned int netem_drop(struct Qdisc* sch)
{
struct sk_buff *skb;
psched_time_t now;
long delay;
skb = skb_peek(&q->qdelay);
if (skb) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
PSCHED_GET_TIME(now);
delay = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
pr_debug("netem_dequeue: delay queue %p@%lu %ld\n",
skb, jiffies, delay);
/* it's baked enough */
if (delay <= 0) {
__skb_unlink(skb, &q->qdelay);
del_timer(&q->timer);
return skb;
}
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
unsigned int len;
if (!timer_pending(&q->timer)) {
q->timer.expires = jiffies + delay;
add_timer(&q->timer);
}
if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
sch->q.qlen--;
sch->stats.drops++;
}
return NULL;
return len;
}
/* Dequeue packet.
* If packet needs to be held up, then put in the delay
* queue and set timer to wakeup later.
* Move all packets that are ready to send from the delay holding
* list to the underlying qdisc, then just call dequeue
*/
static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
struct sk_buff *skb;
psched_time_t now;
skb = netem_get_delayed(q);
if (!skb && (skb = __skb_dequeue(&q->qnormal))) {
/* are we doing out of order packet skip? */
if (q->counter < q->gap) {
pr_debug("netem_dequeue: send %p normally\n", skb);
q->counter++;
} else {
/* don't send now hold for later */
pr_debug("netem_dequeue: hold [%p]@%lu\n", skb, jiffies);
__skb_queue_tail(&q->qdelay, skb);
q->counter = 0;
skb = netem_get_delayed(q);
PSCHED_GET_TIME(now);
while ((skb = skb_peek(&q->delayed)) != NULL) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
long delay
= PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
pr_debug("netem_dequeue: delay queue %p@%lu %ld\n",
skb, jiffies, delay);
/* if more time remaining? */
if (delay > 0) {
mod_timer(&q->timer, jiffies + delay);
break;
}
__skb_unlink(skb, &q->delayed);
if (q->qdisc->enqueue(skb, q->qdisc))
sch->stats.drops++;
}
if (skb)
skb = q->qdisc->dequeue(q->qdisc);
if (skb)
sch->q.qlen--;
return skb;
}
static void netem_timer(unsigned long arg)
static void netem_watchdog(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
pr_debug("netem_timer: fired @%lu\n", jiffies);
pr_debug("netem_watchdog: fired @%lu\n", jiffies);
netif_schedule(sch->dev);
}
......@@ -162,24 +722,63 @@ static void netem_reset(struct Qdisc *sch)
{
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
skb_queue_purge(&q->qnormal);
skb_queue_purge(&q->qdelay);
qdisc_reset(q->qdisc);
skb_queue_purge(&q->delayed);
sch->q.qlen = 0;
del_timer_sync(&q->timer);
}
static int set_fifo_limit(struct Qdisc *q, int limit)
{
struct rtattr *rta;
int ret = -ENOMEM;
rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL);
if (rta) {
rta->rta_type = RTM_NEWQDISC;
rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt));
((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit;
ret = q->ops->change(q, rta);
kfree(rta);
}
return ret;
}
static int netem_change(struct Qdisc *sch, struct rtattr *opt)
{
struct netem_sched_data *q = (struct netem_sched_data *)sch->data;
struct tc_netem_qopt *qopt = RTA_DATA(opt);
struct Qdisc *child;
int ret;
if (qopt->limit)
sch->dev->tx_queue_len = qopt->limit;
if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
return -EINVAL;
q->gap = qopt->gap;
q->loss = qopt->loss;
q->latency = qopt->latency;
child = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
if (!child)
return -EINVAL;
ret = set_fifo_limit(child, qopt->limit);
if (ret) {
qdisc_destroy(child);
return ret;
}
sch_tree_lock(sch);
if (child) {
child = xchg(&q->qdisc, child);
if (child != &noop_qdisc)
qdisc_destroy(child);
q->latency = qopt->latency;
q->jitter = qopt->jitter;
q->limit = qopt->limit;
q->gap = qopt->gap;
q->loss = qopt->loss;
}
sch_tree_unlock(sch);
return 0;
}
......@@ -191,10 +790,11 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt)
if (!opt)
return -EINVAL;
skb_queue_head_init(&q->qnormal);
skb_queue_head_init(&q->qdelay);
skb_queue_head_init(&q->delayed);
q->qdisc = &noop_qdisc;
init_timer(&q->timer);
q->timer.function = netem_timer;
q->timer.function = netem_watchdog;
q->timer.data = (unsigned long) sch;
q->counter = 0;
......@@ -215,6 +815,7 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb)
struct tc_netem_qopt qopt;
qopt.latency = q->latency;
qopt.jitter = q->jitter;
qopt.limit = sch->dev->tx_queue_len;
qopt.loss = q->loss;
qopt.gap = q->gap;
......@@ -234,6 +835,7 @@ static struct Qdisc_ops netem_qdisc_ops = {
.enqueue = netem_enqueue,
.dequeue = netem_dequeue,
.requeue = netem_requeue,
.drop = netem_drop,
.init = netem_init,
.reset = netem_reset,
.destroy = netem_destroy,
......
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