^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) #ifndef __NET_SCHED_RED_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) #define __NET_SCHED_RED_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #include <linux/bug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <net/pkt_sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <net/inet_ecn.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <net/dsfield.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/reciprocal_div.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /* Random Early Detection (RED) algorithm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) =======================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Source: Sally Floyd and Van Jacobson, "Random Early Detection Gateways
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) for Congestion Avoidance", 1993, IEEE/ACM Transactions on Networking.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) This file codes a "divisionless" version of RED algorithm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) as written down in Fig.17 of the paper.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) Short description.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) ------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) When a new packet arrives we calculate the average queue length:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) avg = (1-W)*avg + W*current_queue_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) W is the filter time constant (chosen as 2^(-Wlog)), it controls
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) the inertia of the algorithm. To allow larger bursts, W should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) decreased.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) if (avg > th_max) -> packet marked (dropped).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) if (avg < th_min) -> packet passes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) if (th_min < avg < th_max) we calculate probability:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) Pb = max_P * (avg - th_min)/(th_max-th_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) and mark (drop) packet with this probability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) Pb changes from 0 (at avg==th_min) to max_P (avg==th_max).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) max_P should be small (not 1), usually 0.01..0.02 is good value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) max_P is chosen as a number, so that max_P/(th_max-th_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) is a negative power of two in order arithmetics to contain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) only shifts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) Parameters, settable by user:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) -----------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) qth_min - bytes (should be < qth_max/2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) qth_max - bytes (should be at least 2*qth_min and less limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) Wlog - bits (<32) log(1/W).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) Plog - bits (<32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) Plog is related to max_P by formula:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) max_P = (qth_max-qth_min)/2^Plog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) F.e. if qth_max=128K and qth_min=32K, then Plog=22
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) corresponds to max_P=0.02
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) Scell_log
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) Stab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) Lookup table for log((1-W)^(t/t_ave).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) NOTES:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) Upper bound on W.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) -----------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) If you want to allow bursts of L packets of size S,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) you should choose W:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) L + 1 - th_min/S < (1-(1-W)^L)/W
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) th_min/S = 32 th_min/S = 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) log(W) L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) -1 33
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) -2 35
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) -3 39
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) -4 46
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) -5 57
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) -6 75
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) -7 101
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) -8 135
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) -9 190
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) etc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * Adaptative RED : An Algorithm for Increasing the Robustness of RED's AQM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * (Sally FLoyd, Ramakrishna Gummadi, and Scott Shenker) August 2001
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * Every 500 ms:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * if (avg > target and max_p <= 0.5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * increase max_p : max_p += alpha;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * else if (avg < target and max_p >= 0.01)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) * decrease max_p : max_p *= beta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * target :[qth_min + 0.4*(qth_min - qth_max),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * qth_min + 0.6*(qth_min - qth_max)].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * alpha : min(0.01, max_p / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * beta : 0.9
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * max_P is a Q0.32 fixed point number (with 32 bits mantissa)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * max_P between 0.01 and 0.5 (1% - 50%) [ Its no longer a negative power of two ]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) #define RED_ONE_PERCENT ((u32)DIV_ROUND_CLOSEST(1ULL<<32, 100))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) #define MAX_P_MIN (1 * RED_ONE_PERCENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) #define MAX_P_MAX (50 * RED_ONE_PERCENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) #define MAX_P_ALPHA(val) min(MAX_P_MIN, val / 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) #define RED_STAB_SIZE 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) #define RED_STAB_MASK (RED_STAB_SIZE - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) struct red_stats {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) u32 prob_drop; /* Early probability drops */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) u32 prob_mark; /* Early probability marks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) u32 forced_drop; /* Forced drops, qavg > max_thresh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) u32 forced_mark; /* Forced marks, qavg > max_thresh */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) u32 pdrop; /* Drops due to queue limits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) u32 other; /* Drops due to drop() calls */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) struct red_parms {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) /* Parameters */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) u32 qth_min; /* Min avg length threshold: Wlog scaled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) u32 qth_max; /* Max avg length threshold: Wlog scaled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) u32 Scell_max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) u32 max_P; /* probability, [0 .. 1.0] 32 scaled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /* reciprocal_value(max_P / qth_delta) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct reciprocal_value max_P_reciprocal;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) u32 qth_delta; /* max_th - min_th */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) u32 target_min; /* min_th + 0.4*(max_th - min_th) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) u32 target_max; /* min_th + 0.6*(max_th - min_th) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) u8 Scell_log;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) u8 Wlog; /* log(W) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) u8 Plog; /* random number bits */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) u8 Stab[RED_STAB_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) struct red_vars {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) /* Variables */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) int qcount; /* Number of packets since last random
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) number generation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) u32 qR; /* Cached random number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) unsigned long qavg; /* Average queue length: Wlog scaled */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) ktime_t qidlestart; /* Start of current idle period */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static inline u32 red_maxp(u8 Plog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return Plog < 32 ? (~0U >> Plog) : ~0U;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static inline void red_set_vars(struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) /* Reset average queue length, the value is strictly bound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * to the parameters below, reseting hurts a bit but leaving
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * it might result in an unreasonable qavg for a while. --TGR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) v->qavg = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) v->qcount = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static inline bool red_check_params(u32 qth_min, u32 qth_max, u8 Wlog,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) u8 Scell_log, u8 *stab)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) if (fls(qth_min) + Wlog >= 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (fls(qth_max) + Wlog >= 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) if (Scell_log >= 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) if (qth_max < qth_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (stab) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) for (i = 0; i < RED_STAB_SIZE; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) if (stab[i] >= 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) static inline int red_get_flags(unsigned char qopt_flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) unsigned char historic_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) struct nlattr *flags_attr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) unsigned char supported_mask,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) struct nla_bitfield32 *p_flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) unsigned char *p_userbits,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) struct netlink_ext_ack *extack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) struct nla_bitfield32 flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) if (qopt_flags && flags_attr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) NL_SET_ERR_MSG_MOD(extack, "flags should be passed either through qopt, or through a dedicated attribute");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (flags_attr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) flags = nla_get_bitfield32(flags_attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) flags.selector = historic_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) flags.value = qopt_flags & historic_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) *p_flags = flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) *p_userbits = qopt_flags & ~historic_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static inline int red_validate_flags(unsigned char flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) struct netlink_ext_ack *extack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) if ((flags & TC_RED_NODROP) && !(flags & TC_RED_ECN)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) NL_SET_ERR_MSG_MOD(extack, "nodrop mode is only meaningful with ECN");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) static inline void red_set_parms(struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) u32 qth_min, u32 qth_max, u8 Wlog, u8 Plog,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) u8 Scell_log, u8 *stab, u32 max_P)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) int delta = qth_max - qth_min;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) u32 max_p_delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) p->qth_min = qth_min << Wlog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) p->qth_max = qth_max << Wlog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) p->Wlog = Wlog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) p->Plog = Plog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) if (delta <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) delta = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) p->qth_delta = delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) if (!max_P) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) max_P = red_maxp(Plog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) max_P *= delta; /* max_P = (qth_max - qth_min)/2^Plog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) p->max_P = max_P;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) max_p_delta = max_P / delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) max_p_delta = max(max_p_delta, 1U);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) p->max_P_reciprocal = reciprocal_value(max_p_delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) /* RED Adaptative target :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * [min_th + 0.4*(min_th - max_th),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * min_th + 0.6*(min_th - max_th)].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) delta /= 5;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) p->target_min = qth_min + 2*delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) p->target_max = qth_min + 3*delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) p->Scell_log = Scell_log;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) p->Scell_max = (255 << Scell_log);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) if (stab)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) memcpy(p->Stab, stab, sizeof(p->Stab));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) static inline int red_is_idling(const struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) return v->qidlestart != 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) static inline void red_start_of_idle_period(struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) v->qidlestart = ktime_get();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) static inline void red_end_of_idle_period(struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) v->qidlestart = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) static inline void red_restart(struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) red_end_of_idle_period(v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) v->qavg = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) v->qcount = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) static inline unsigned long red_calc_qavg_from_idle_time(const struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) const struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) s64 delta = ktime_us_delta(ktime_get(), v->qidlestart);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) long us_idle = min_t(s64, delta, p->Scell_max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) int shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * The problem: ideally, average length queue recalcultion should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * be done over constant clock intervals. This is too expensive, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * that the calculation is driven by outgoing packets.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * When the queue is idle we have to model this clock by hand.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * SF+VJ proposed to "generate":
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) * m = idletime / (average_pkt_size / bandwidth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * dummy packets as a burst after idle time, i.e.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * v->qavg *= (1-W)^m
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * This is an apparently overcomplicated solution (f.e. we have to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * precompute a table to make this calculation in reasonable time)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) * I believe that a simpler model may be used here,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * but it is field for experiments.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) shift = p->Stab[(us_idle >> p->Scell_log) & RED_STAB_MASK];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) if (shift)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) return v->qavg >> shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) /* Approximate initial part of exponent with linear function:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * (1-W)^m ~= 1-mW + ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * Seems, it is the best solution to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * problem of too coarse exponent tabulation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) us_idle = (v->qavg * (u64)us_idle) >> p->Scell_log;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (us_idle < (v->qavg >> 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) return v->qavg - us_idle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) return v->qavg >> 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) static inline unsigned long red_calc_qavg_no_idle_time(const struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) const struct red_vars *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) unsigned int backlog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * NOTE: v->qavg is fixed point number with point at Wlog.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * The formula below is equvalent to floating point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * version:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * qavg = qavg*(1-W) + backlog*W;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * --ANK (980924)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) return v->qavg + (backlog - (v->qavg >> p->Wlog));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) static inline unsigned long red_calc_qavg(const struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) const struct red_vars *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) unsigned int backlog)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) if (!red_is_idling(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) return red_calc_qavg_no_idle_time(p, v, backlog);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) return red_calc_qavg_from_idle_time(p, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) static inline u32 red_random(const struct red_parms *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) return reciprocal_divide(prandom_u32(), p->max_P_reciprocal);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) static inline int red_mark_probability(const struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) const struct red_vars *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) unsigned long qavg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) /* The formula used below causes questions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) OK. qR is random number in the interval
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) (0..1/max_P)*(qth_max-qth_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) i.e. 0..(2^Plog). If we used floating point
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) arithmetics, it would be: (2^Plog)*rnd_num,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) where rnd_num is less 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) Taking into account, that qavg have fixed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) point at Wlog, two lines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) below have the following floating point equivalent:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) max_P*(qavg - qth_min)/(qth_max-qth_min) < rnd/qcount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) Any questions? --ANK (980924)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) return !(((qavg - p->qth_min) >> p->Wlog) * v->qcount < v->qR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) enum {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) RED_BELOW_MIN_THRESH,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) RED_BETWEEN_TRESH,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) RED_ABOVE_MAX_TRESH,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) static inline int red_cmp_thresh(const struct red_parms *p, unsigned long qavg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) if (qavg < p->qth_min)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) return RED_BELOW_MIN_THRESH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) else if (qavg >= p->qth_max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) return RED_ABOVE_MAX_TRESH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) return RED_BETWEEN_TRESH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) enum {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) RED_DONT_MARK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) RED_PROB_MARK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) RED_HARD_MARK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) static inline int red_action(const struct red_parms *p,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) struct red_vars *v,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) unsigned long qavg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) switch (red_cmp_thresh(p, qavg)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) case RED_BELOW_MIN_THRESH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) v->qcount = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) return RED_DONT_MARK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) case RED_BETWEEN_TRESH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) if (++v->qcount) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) if (red_mark_probability(p, v, qavg)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) v->qcount = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) v->qR = red_random(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) return RED_PROB_MARK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) v->qR = red_random(p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) return RED_DONT_MARK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) case RED_ABOVE_MAX_TRESH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) v->qcount = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) return RED_HARD_MARK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) return RED_DONT_MARK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) static inline void red_adaptative_algo(struct red_parms *p, struct red_vars *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) unsigned long qavg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) u32 max_p_delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) qavg = v->qavg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) if (red_is_idling(v))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) qavg = red_calc_qavg_from_idle_time(p, v);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) /* v->qavg is fixed point number with point at Wlog */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) qavg >>= p->Wlog;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) if (qavg > p->target_max && p->max_P <= MAX_P_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) p->max_P += MAX_P_ALPHA(p->max_P); /* maxp = maxp + alpha */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) else if (qavg < p->target_min && p->max_P >= MAX_P_MIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) p->max_P = (p->max_P/10)*9; /* maxp = maxp * Beta */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) max_p_delta = DIV_ROUND_CLOSEST(p->max_P, p->qth_delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) max_p_delta = max(max_p_delta, 1U);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) p->max_P_reciprocal = reciprocal_value(max_p_delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) #endif
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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