dn_sched_qfq.c revision 294858
1204591Sluigi/* 2204591Sluigi * Copyright (c) 2010 Fabio Checconi, Luigi Rizzo, Paolo Valente 3204591Sluigi * All rights reserved 4204591Sluigi * 5204591Sluigi * Redistribution and use in source and binary forms, with or without 6204591Sluigi * modification, are permitted provided that the following conditions 7204591Sluigi * are met: 8204591Sluigi * 1. Redistributions of source code must retain the above copyright 9204591Sluigi * notice, this list of conditions and the following disclaimer. 10204591Sluigi * 2. Redistributions in binary form must reproduce the above copyright 11204591Sluigi * notice, this list of conditions and the following disclaimer in the 12204591Sluigi * documentation and/or other materials provided with the distribution. 13204591Sluigi * 14204591Sluigi * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15204591Sluigi * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16204591Sluigi * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17204591Sluigi * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18204591Sluigi * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19204591Sluigi * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20204591Sluigi * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21204591Sluigi * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22204591Sluigi * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23204591Sluigi * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24204591Sluigi * SUCH DAMAGE. 25204591Sluigi */ 26204591Sluigi 27204591Sluigi/* 28204591Sluigi * $FreeBSD: head/sys/netpfil/ipfw/dn_sched_qfq.c 294858 2016-01-26 23:36:18Z luigi $ 29204591Sluigi */ 30204591Sluigi 31204591Sluigi#ifdef _KERNEL 32204591Sluigi#include <sys/malloc.h> 33204591Sluigi#include <sys/socket.h> 34204591Sluigi#include <sys/socketvar.h> 35204591Sluigi#include <sys/kernel.h> 36204591Sluigi#include <sys/mbuf.h> 37204591Sluigi#include <sys/module.h> 38204591Sluigi#include <net/if.h> /* IFNAMSIZ */ 39204591Sluigi#include <netinet/in.h> 40204591Sluigi#include <netinet/ip_var.h> /* ipfw_rule_ref */ 41204591Sluigi#include <netinet/ip_fw.h> /* flow_id */ 42204591Sluigi#include <netinet/ip_dummynet.h> 43240494Sglebius#include <netpfil/ipfw/dn_heap.h> 44240494Sglebius#include <netpfil/ipfw/ip_dn_private.h> 45240494Sglebius#include <netpfil/ipfw/dn_sched.h> 46204591Sluigi#else 47204591Sluigi#include <dn_test.h> 48204591Sluigi#endif 49204591Sluigi 50204591Sluigi#ifdef QFQ_DEBUG 51294858Sluigi#define _P64 unsigned long long /* cast for printing uint64_t */ 52204591Sluigistruct qfq_sched; 53204591Sluigistatic void dump_sched(struct qfq_sched *q, const char *msg); 54204591Sluigi#define NO(x) x 55204591Sluigi#else 56204591Sluigi#define NO(x) 57204591Sluigi#endif 58204591Sluigi#define DN_SCHED_QFQ 4 // XXX Where? 59204591Sluigitypedef unsigned long bitmap; 60204591Sluigi 61204591Sluigi/* 62204591Sluigi * bitmaps ops are critical. Some linux versions have __fls 63204591Sluigi * and the bitmap ops. Some machines have ffs 64294761Sluigi * NOTE: fls() returns 1 for the least significant bit, 65294761Sluigi * __fls() returns 0 for the same case. 66294761Sluigi * We use the base-0 version __fls() to match the description in 67294761Sluigi * the ToN QFQ paper 68204591Sluigi */ 69213253Sluigi#if defined(_WIN32) || (defined(__MIPSEL__) && defined(LINUX_24)) 70204591Sluigiint fls(unsigned int n) 71204591Sluigi{ 72204591Sluigi int i = 0; 73204591Sluigi for (i = 0; n > 0; n >>= 1, i++) 74204591Sluigi ; 75204591Sluigi return i; 76204591Sluigi} 77204591Sluigi#endif 78204591Sluigi 79213253Sluigi#if !defined(_KERNEL) || defined( __FreeBSD__ ) || defined(_WIN32) || (defined(__MIPSEL__) && defined(LINUX_24)) 80204591Sluigistatic inline unsigned long __fls(unsigned long word) 81204591Sluigi{ 82204591Sluigi return fls(word) - 1; 83204591Sluigi} 84204591Sluigi#endif 85204591Sluigi 86204591Sluigi#if !defined(_KERNEL) || !defined(__linux__) 87204591Sluigi#ifdef QFQ_DEBUG 88294858Sluigistatic int test_bit(int ix, bitmap *p) 89204591Sluigi{ 90204591Sluigi if (ix < 0 || ix > 31) 91204591Sluigi D("bad index %d", ix); 92204591Sluigi return *p & (1<<ix); 93204591Sluigi} 94294858Sluigistatic void __set_bit(int ix, bitmap *p) 95204591Sluigi{ 96204591Sluigi if (ix < 0 || ix > 31) 97204591Sluigi D("bad index %d", ix); 98204591Sluigi *p |= (1<<ix); 99204591Sluigi} 100294858Sluigistatic void __clear_bit(int ix, bitmap *p) 101204591Sluigi{ 102204591Sluigi if (ix < 0 || ix > 31) 103204591Sluigi D("bad index %d", ix); 104204591Sluigi *p &= ~(1<<ix); 105204591Sluigi} 106204591Sluigi#else /* !QFQ_DEBUG */ 107204591Sluigi/* XXX do we have fast version, or leave it to the compiler ? */ 108204591Sluigi#define test_bit(ix, pData) ((*pData) & (1<<(ix))) 109204591Sluigi#define __set_bit(ix, pData) (*pData) |= (1<<(ix)) 110204591Sluigi#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix)) 111204591Sluigi#endif /* !QFQ_DEBUG */ 112204591Sluigi#endif /* !__linux__ */ 113204591Sluigi 114204591Sluigi#ifdef __MIPSEL__ 115213253Sluigi#define __clear_bit(ix, pData) (*pData) &= ~(1<<(ix)) 116204591Sluigi#endif 117204591Sluigi 118204591Sluigi/*-------------------------------------------*/ 119204591Sluigi/* 120204591Sluigi 121204591SluigiVirtual time computations. 122204591Sluigi 123204591SluigiS, F and V are all computed in fixed point arithmetic with 124204591SluigiFRAC_BITS decimal bits. 125204591Sluigi 126204591Sluigi QFQ_MAX_INDEX is the maximum index allowed for a group. We need 127204591Sluigi one bit per index. 128204591Sluigi QFQ_MAX_WSHIFT is the maximum power of two supported as a weight. 129204591Sluigi The layout of the bits is as below: 130204591Sluigi 131204591Sluigi [ MTU_SHIFT ][ FRAC_BITS ] 132204591Sluigi [ MAX_INDEX ][ MIN_SLOT_SHIFT ] 133204591Sluigi ^.__grp->index = 0 134204591Sluigi *.__grp->slot_shift 135204591Sluigi 136204591Sluigi where MIN_SLOT_SHIFT is derived by difference from the others. 137204591Sluigi 138204591SluigiThe max group index corresponds to Lmax/w_min, where 139204591SluigiLmax=1<<MTU_SHIFT, w_min = 1 . 140204591SluigiFrom this, and knowing how many groups (MAX_INDEX) we want, 141204591Sluigiwe can derive the shift corresponding to each group. 142204591Sluigi 143204591SluigiBecause we often need to compute 144204591Sluigi F = S + len/w_i and V = V + len/wsum 145204591Sluigiinstead of storing w_i store the value 146204591Sluigi inv_w = (1<<FRAC_BITS)/w_i 147204591Sluigiso we can do F = S + len * inv_w * wsum. 148204591SluigiWe use W_TOT in the formulas so we can easily move between 149204591Sluigistatic and adaptive weight sum. 150204591Sluigi 151204591SluigiThe per-scheduler-instance data contain all the data structures 152204591Sluigifor the scheduler: bitmaps and bucket lists. 153204591Sluigi 154204591Sluigi */ 155204591Sluigi/* 156204591Sluigi * Maximum number of consecutive slots occupied by backlogged classes 157204591Sluigi * inside a group. This is approx lmax/lmin + 5. 158204591Sluigi * XXX check because it poses constraints on MAX_INDEX 159204591Sluigi */ 160204591Sluigi#define QFQ_MAX_SLOTS 32 161204591Sluigi/* 162204591Sluigi * Shifts used for class<->group mapping. Class weights are 163204591Sluigi * in the range [1, QFQ_MAX_WEIGHT], we to map each class i to the 164204591Sluigi * group with the smallest index that can support the L_i / r_i 165204591Sluigi * configured for the class. 166204591Sluigi * 167204591Sluigi * grp->index is the index of the group; and grp->slot_shift 168204591Sluigi * is the shift for the corresponding (scaled) sigma_i. 169204591Sluigi * 170204591Sluigi * When computing the group index, we do (len<<FP_SHIFT)/weight, 171204591Sluigi * then compute an FLS (which is like a log2()), and if the result 172204591Sluigi * is below the MAX_INDEX region we use 0 (which is the same as 173204591Sluigi * using a larger len). 174204591Sluigi */ 175204591Sluigi#define QFQ_MAX_INDEX 19 176204591Sluigi#define QFQ_MAX_WSHIFT 16 /* log2(max_weight) */ 177204591Sluigi 178204591Sluigi#define QFQ_MAX_WEIGHT (1<<QFQ_MAX_WSHIFT) 179204591Sluigi#define QFQ_MAX_WSUM (2*QFQ_MAX_WEIGHT) 180204591Sluigi 181204591Sluigi#define FRAC_BITS 30 /* fixed point arithmetic */ 182204591Sluigi#define ONE_FP (1UL << FRAC_BITS) 183204591Sluigi 184204591Sluigi#define QFQ_MTU_SHIFT 11 /* log2(max_len) */ 185204591Sluigi#define QFQ_MIN_SLOT_SHIFT (FRAC_BITS + QFQ_MTU_SHIFT - QFQ_MAX_INDEX) 186204591Sluigi 187204591Sluigi/* 188204591Sluigi * Possible group states, also indexes for the bitmaps array in 189204591Sluigi * struct qfq_queue. We rely on ER, IR, EB, IB being numbered 0..3 190204591Sluigi */ 191204591Sluigienum qfq_state { ER, IR, EB, IB, QFQ_MAX_STATE }; 192204591Sluigi 193204591Sluigistruct qfq_group; 194204591Sluigi/* 195204591Sluigi * additional queue info. Some of this info should come from 196204591Sluigi * the flowset, we copy them here for faster processing. 197204591Sluigi * This is an overlay of the struct dn_queue 198204591Sluigi */ 199204591Sluigistruct qfq_class { 200204591Sluigi struct dn_queue _q; 201204591Sluigi uint64_t S, F; /* flow timestamps (exact) */ 202204591Sluigi struct qfq_class *next; /* Link for the slot list. */ 203204591Sluigi 204204591Sluigi /* group we belong to. In principle we would need the index, 205204591Sluigi * which is log_2(lmax/weight), but we never reference it 206204591Sluigi * directly, only the group. 207204591Sluigi */ 208204591Sluigi struct qfq_group *grp; 209204591Sluigi 210204591Sluigi /* these are copied from the flowset. */ 211204591Sluigi uint32_t inv_w; /* ONE_FP/weight */ 212204591Sluigi uint32_t lmax; /* Max packet size for this flow. */ 213204591Sluigi}; 214204591Sluigi 215204591Sluigi/* Group descriptor, see the paper for details. 216204591Sluigi * Basically this contains the bucket lists 217204591Sluigi */ 218204591Sluigistruct qfq_group { 219204591Sluigi uint64_t S, F; /* group timestamps (approx). */ 220204591Sluigi unsigned int slot_shift; /* Slot shift. */ 221204591Sluigi unsigned int index; /* Group index. */ 222204591Sluigi unsigned int front; /* Index of the front slot. */ 223204591Sluigi bitmap full_slots; /* non-empty slots */ 224204591Sluigi 225204591Sluigi /* Array of lists of active classes. */ 226204591Sluigi struct qfq_class *slots[QFQ_MAX_SLOTS]; 227204591Sluigi}; 228204591Sluigi 229204591Sluigi/* scheduler instance descriptor. */ 230204591Sluigistruct qfq_sched { 231204591Sluigi uint64_t V; /* Precise virtual time. */ 232204591Sluigi uint32_t wsum; /* weight sum */ 233285362Sluigi uint32_t iwsum; /* inverse weight sum */ 234294858Sluigi NO(uint32_t i_wsum;) /* ONE_FP/w_sum */ 235294858Sluigi NO(uint32_t queued;) /* debugging */ 236294858Sluigi NO(uint32_t loops;) /* debugging */ 237204591Sluigi bitmap bitmaps[QFQ_MAX_STATE]; /* Group bitmaps. */ 238204591Sluigi struct qfq_group groups[QFQ_MAX_INDEX + 1]; /* The groups. */ 239204591Sluigi}; 240204591Sluigi 241204591Sluigi/*---- support functions ----------------------------*/ 242204591Sluigi 243204591Sluigi/* Generic comparison function, handling wraparound. */ 244204591Sluigistatic inline int qfq_gt(uint64_t a, uint64_t b) 245204591Sluigi{ 246204591Sluigi return (int64_t)(a - b) > 0; 247204591Sluigi} 248204591Sluigi 249204591Sluigi/* Round a precise timestamp to its slotted value. */ 250204591Sluigistatic inline uint64_t qfq_round_down(uint64_t ts, unsigned int shift) 251204591Sluigi{ 252204591Sluigi return ts & ~((1ULL << shift) - 1); 253204591Sluigi} 254204591Sluigi 255204591Sluigi/* return the pointer to the group with lowest index in the bitmap */ 256204591Sluigistatic inline struct qfq_group *qfq_ffs(struct qfq_sched *q, 257204591Sluigi unsigned long bitmap) 258204591Sluigi{ 259204591Sluigi int index = ffs(bitmap) - 1; // zero-based 260204591Sluigi return &q->groups[index]; 261204591Sluigi} 262204591Sluigi 263204591Sluigi/* 264204591Sluigi * Calculate a flow index, given its weight and maximum packet length. 265204591Sluigi * index = log_2(maxlen/weight) but we need to apply the scaling. 266204591Sluigi * This is used only once at flow creation. 267204591Sluigi */ 268204591Sluigistatic int qfq_calc_index(uint32_t inv_w, unsigned int maxlen) 269204591Sluigi{ 270204591Sluigi uint64_t slot_size = (uint64_t)maxlen *inv_w; 271204591Sluigi unsigned long size_map; 272204591Sluigi int index = 0; 273204591Sluigi 274204591Sluigi size_map = (unsigned long)(slot_size >> QFQ_MIN_SLOT_SHIFT); 275204591Sluigi if (!size_map) 276204591Sluigi goto out; 277204591Sluigi 278204591Sluigi index = __fls(size_map) + 1; // basically a log_2() 279204591Sluigi index -= !(slot_size - (1ULL << (index + QFQ_MIN_SLOT_SHIFT - 1))); 280204591Sluigi 281204591Sluigi if (index < 0) 282204591Sluigi index = 0; 283204591Sluigi 284204591Sluigiout: 285204591Sluigi ND("W = %d, L = %d, I = %d\n", ONE_FP/inv_w, maxlen, index); 286204591Sluigi return index; 287204591Sluigi} 288204591Sluigi/*---- end support functions ----*/ 289204591Sluigi 290204591Sluigi/*-------- API calls --------------------------------*/ 291204591Sluigi/* 292204591Sluigi * Validate and copy parameters from flowset. 293204591Sluigi */ 294204591Sluigistatic int 295204591Sluigiqfq_new_queue(struct dn_queue *_q) 296204591Sluigi{ 297204591Sluigi struct qfq_sched *q = (struct qfq_sched *)(_q->_si + 1); 298204591Sluigi struct qfq_class *cl = (struct qfq_class *)_q; 299204591Sluigi int i; 300204591Sluigi uint32_t w; /* approximated weight */ 301204591Sluigi 302204591Sluigi /* import parameters from the flowset. They should be correct 303204591Sluigi * already. 304204591Sluigi */ 305204591Sluigi w = _q->fs->fs.par[0]; 306204591Sluigi cl->lmax = _q->fs->fs.par[1]; 307204591Sluigi if (!w || w > QFQ_MAX_WEIGHT) { 308204591Sluigi w = 1; 309204591Sluigi D("rounding weight to 1"); 310204591Sluigi } 311204591Sluigi cl->inv_w = ONE_FP/w; 312204591Sluigi w = ONE_FP/cl->inv_w; 313204591Sluigi if (q->wsum + w > QFQ_MAX_WSUM) 314204591Sluigi return EINVAL; 315204591Sluigi 316204591Sluigi i = qfq_calc_index(cl->inv_w, cl->lmax); 317204591Sluigi cl->grp = &q->groups[i]; 318204591Sluigi q->wsum += w; 319285362Sluigi q->iwsum = ONE_FP / q->wsum; /* XXX note theory */ 320204591Sluigi // XXX cl->S = q->V; ? 321204591Sluigi return 0; 322204591Sluigi} 323204591Sluigi 324204591Sluigi/* remove an empty queue */ 325204591Sluigistatic int 326204591Sluigiqfq_free_queue(struct dn_queue *_q) 327204591Sluigi{ 328204591Sluigi struct qfq_sched *q = (struct qfq_sched *)(_q->_si + 1); 329204591Sluigi struct qfq_class *cl = (struct qfq_class *)_q; 330204591Sluigi if (cl->inv_w) { 331204591Sluigi q->wsum -= ONE_FP/cl->inv_w; 332285362Sluigi if (q->wsum != 0) 333285362Sluigi q->iwsum = ONE_FP / q->wsum; 334204591Sluigi cl->inv_w = 0; /* reset weight to avoid run twice */ 335204591Sluigi } 336204591Sluigi return 0; 337204591Sluigi} 338204591Sluigi 339204591Sluigi/* Calculate a mask to mimic what would be ffs_from(). */ 340204591Sluigistatic inline unsigned long 341204591Sluigimask_from(unsigned long bitmap, int from) 342204591Sluigi{ 343204591Sluigi return bitmap & ~((1UL << from) - 1); 344204591Sluigi} 345204591Sluigi 346204591Sluigi/* 347204591Sluigi * The state computation relies on ER=0, IR=1, EB=2, IB=3 348204591Sluigi * First compute eligibility comparing grp->S, q->V, 349204591Sluigi * then check if someone is blocking us and possibly add EB 350204591Sluigi */ 351204591Sluigistatic inline unsigned int 352204591Sluigiqfq_calc_state(struct qfq_sched *q, struct qfq_group *grp) 353204591Sluigi{ 354204591Sluigi /* if S > V we are not eligible */ 355204591Sluigi unsigned int state = qfq_gt(grp->S, q->V); 356204591Sluigi unsigned long mask = mask_from(q->bitmaps[ER], grp->index); 357204591Sluigi struct qfq_group *next; 358204591Sluigi 359204591Sluigi if (mask) { 360204591Sluigi next = qfq_ffs(q, mask); 361204591Sluigi if (qfq_gt(grp->F, next->F)) 362204591Sluigi state |= EB; 363204591Sluigi } 364204591Sluigi 365204591Sluigi return state; 366204591Sluigi} 367204591Sluigi 368204591Sluigi/* 369204591Sluigi * In principle 370204591Sluigi * q->bitmaps[dst] |= q->bitmaps[src] & mask; 371204591Sluigi * q->bitmaps[src] &= ~mask; 372204591Sluigi * but we should make sure that src != dst 373204591Sluigi */ 374204591Sluigistatic inline void 375204591Sluigiqfq_move_groups(struct qfq_sched *q, unsigned long mask, int src, int dst) 376204591Sluigi{ 377204591Sluigi q->bitmaps[dst] |= q->bitmaps[src] & mask; 378204591Sluigi q->bitmaps[src] &= ~mask; 379204591Sluigi} 380204591Sluigi 381204591Sluigistatic inline void 382204591Sluigiqfq_unblock_groups(struct qfq_sched *q, int index, uint64_t old_finish) 383204591Sluigi{ 384204591Sluigi unsigned long mask = mask_from(q->bitmaps[ER], index + 1); 385204591Sluigi struct qfq_group *next; 386204591Sluigi 387204591Sluigi if (mask) { 388204591Sluigi next = qfq_ffs(q, mask); 389204591Sluigi if (!qfq_gt(next->F, old_finish)) 390204591Sluigi return; 391204591Sluigi } 392204591Sluigi 393204591Sluigi mask = (1UL << index) - 1; 394204591Sluigi qfq_move_groups(q, mask, EB, ER); 395204591Sluigi qfq_move_groups(q, mask, IB, IR); 396204591Sluigi} 397204591Sluigi 398204591Sluigi/* 399204591Sluigi * perhaps 400204591Sluigi * 401204591Sluigi old_V ^= q->V; 402204591Sluigi old_V >>= QFQ_MIN_SLOT_SHIFT; 403204591Sluigi if (old_V) { 404204591Sluigi ... 405204591Sluigi } 406204591Sluigi * 407204591Sluigi */ 408204591Sluigistatic inline void 409204591Sluigiqfq_make_eligible(struct qfq_sched *q, uint64_t old_V) 410204591Sluigi{ 411204591Sluigi unsigned long mask, vslot, old_vslot; 412204591Sluigi 413204591Sluigi vslot = q->V >> QFQ_MIN_SLOT_SHIFT; 414204591Sluigi old_vslot = old_V >> QFQ_MIN_SLOT_SHIFT; 415204591Sluigi 416204591Sluigi if (vslot != old_vslot) { 417294761Sluigi /* must be 2ULL, see ToN QFQ article fig.5, we use base-0 fls */ 418294761Sluigi mask = (2ULL << (__fls(vslot ^ old_vslot))) - 1; 419204591Sluigi qfq_move_groups(q, mask, IR, ER); 420204591Sluigi qfq_move_groups(q, mask, IB, EB); 421204591Sluigi } 422204591Sluigi} 423204591Sluigi 424204591Sluigi/* 425204591Sluigi * XXX we should make sure that slot becomes less than 32. 426204591Sluigi * This is guaranteed by the input values. 427204591Sluigi * roundedS is always cl->S rounded on grp->slot_shift bits. 428204591Sluigi */ 429204591Sluigistatic inline void 430204591Sluigiqfq_slot_insert(struct qfq_group *grp, struct qfq_class *cl, uint64_t roundedS) 431204591Sluigi{ 432204591Sluigi uint64_t slot = (roundedS - grp->S) >> grp->slot_shift; 433204591Sluigi unsigned int i = (grp->front + slot) % QFQ_MAX_SLOTS; 434204591Sluigi 435204591Sluigi cl->next = grp->slots[i]; 436204591Sluigi grp->slots[i] = cl; 437204591Sluigi __set_bit(slot, &grp->full_slots); 438204591Sluigi} 439204591Sluigi 440204591Sluigi/* 441204591Sluigi * remove the entry from the slot 442204591Sluigi */ 443204591Sluigistatic inline void 444204591Sluigiqfq_front_slot_remove(struct qfq_group *grp) 445204591Sluigi{ 446204591Sluigi struct qfq_class **h = &grp->slots[grp->front]; 447204591Sluigi 448204591Sluigi *h = (*h)->next; 449204591Sluigi if (!*h) 450204591Sluigi __clear_bit(0, &grp->full_slots); 451204591Sluigi} 452204591Sluigi 453204591Sluigi/* 454204591Sluigi * Returns the first full queue in a group. As a side effect, 455204591Sluigi * adjust the bucket list so the first non-empty bucket is at 456204591Sluigi * position 0 in full_slots. 457204591Sluigi */ 458204591Sluigistatic inline struct qfq_class * 459204591Sluigiqfq_slot_scan(struct qfq_group *grp) 460204591Sluigi{ 461204591Sluigi int i; 462204591Sluigi 463204591Sluigi ND("grp %d full %x", grp->index, grp->full_slots); 464204591Sluigi if (!grp->full_slots) 465204591Sluigi return NULL; 466204591Sluigi 467204591Sluigi i = ffs(grp->full_slots) - 1; // zero-based 468204591Sluigi if (i > 0) { 469204591Sluigi grp->front = (grp->front + i) % QFQ_MAX_SLOTS; 470204591Sluigi grp->full_slots >>= i; 471204591Sluigi } 472204591Sluigi 473204591Sluigi return grp->slots[grp->front]; 474204591Sluigi} 475204591Sluigi 476204591Sluigi/* 477204591Sluigi * adjust the bucket list. When the start time of a group decreases, 478204591Sluigi * we move the index down (modulo QFQ_MAX_SLOTS) so we don't need to 479204591Sluigi * move the objects. The mask of occupied slots must be shifted 480204591Sluigi * because we use ffs() to find the first non-empty slot. 481204591Sluigi * This covers decreases in the group's start time, but what about 482204591Sluigi * increases of the start time ? 483204591Sluigi * Here too we should make sure that i is less than 32 484204591Sluigi */ 485204591Sluigistatic inline void 486204591Sluigiqfq_slot_rotate(struct qfq_sched *q, struct qfq_group *grp, uint64_t roundedS) 487204591Sluigi{ 488204591Sluigi unsigned int i = (grp->S - roundedS) >> grp->slot_shift; 489204591Sluigi 490294858Sluigi (void)q; 491204591Sluigi grp->full_slots <<= i; 492204591Sluigi grp->front = (grp->front - i) % QFQ_MAX_SLOTS; 493204591Sluigi} 494204591Sluigi 495204591Sluigi 496204591Sluigistatic inline void 497204591Sluigiqfq_update_eligible(struct qfq_sched *q, uint64_t old_V) 498204591Sluigi{ 499204591Sluigi bitmap ineligible; 500204591Sluigi 501204591Sluigi ineligible = q->bitmaps[IR] | q->bitmaps[IB]; 502204591Sluigi if (ineligible) { 503204591Sluigi if (!q->bitmaps[ER]) { 504204591Sluigi struct qfq_group *grp; 505204591Sluigi grp = qfq_ffs(q, ineligible); 506204591Sluigi if (qfq_gt(grp->S, q->V)) 507204591Sluigi q->V = grp->S; 508204591Sluigi } 509204591Sluigi qfq_make_eligible(q, old_V); 510204591Sluigi } 511204591Sluigi} 512204591Sluigi 513204591Sluigi/* 514204591Sluigi * Updates the class, returns true if also the group needs to be updated. 515204591Sluigi */ 516204591Sluigistatic inline int 517204591Sluigiqfq_update_class(struct qfq_sched *q, struct qfq_group *grp, 518204591Sluigi struct qfq_class *cl) 519204591Sluigi{ 520204591Sluigi 521294858Sluigi (void)q; 522204591Sluigi cl->S = cl->F; 523204591Sluigi if (cl->_q.mq.head == NULL) { 524204591Sluigi qfq_front_slot_remove(grp); 525204591Sluigi } else { 526204591Sluigi unsigned int len; 527204591Sluigi uint64_t roundedS; 528204591Sluigi 529204591Sluigi len = cl->_q.mq.head->m_pkthdr.len; 530204591Sluigi cl->F = cl->S + (uint64_t)len * cl->inv_w; 531204591Sluigi roundedS = qfq_round_down(cl->S, grp->slot_shift); 532204591Sluigi if (roundedS == grp->S) 533204591Sluigi return 0; 534204591Sluigi 535204591Sluigi qfq_front_slot_remove(grp); 536204591Sluigi qfq_slot_insert(grp, cl, roundedS); 537204591Sluigi } 538204591Sluigi return 1; 539204591Sluigi} 540204591Sluigi 541204591Sluigistatic struct mbuf * 542204591Sluigiqfq_dequeue(struct dn_sch_inst *si) 543204591Sluigi{ 544204591Sluigi struct qfq_sched *q = (struct qfq_sched *)(si + 1); 545204591Sluigi struct qfq_group *grp; 546204591Sluigi struct qfq_class *cl; 547204591Sluigi struct mbuf *m; 548204591Sluigi uint64_t old_V; 549204591Sluigi 550204591Sluigi NO(q->loops++;) 551204591Sluigi if (!q->bitmaps[ER]) { 552204591Sluigi NO(if (q->queued) 553204591Sluigi dump_sched(q, "start dequeue");) 554204591Sluigi return NULL; 555204591Sluigi } 556204591Sluigi 557204591Sluigi grp = qfq_ffs(q, q->bitmaps[ER]); 558204591Sluigi 559204591Sluigi cl = grp->slots[grp->front]; 560204591Sluigi /* extract from the first bucket in the bucket list */ 561204591Sluigi m = dn_dequeue(&cl->_q); 562204591Sluigi 563204591Sluigi if (!m) { 564204591Sluigi D("BUG/* non-workconserving leaf */"); 565204591Sluigi return NULL; 566204591Sluigi } 567204591Sluigi NO(q->queued--;) 568204591Sluigi old_V = q->V; 569285362Sluigi q->V += (uint64_t)m->m_pkthdr.len * q->iwsum; 570204591Sluigi ND("m is %p F 0x%llx V now 0x%llx", m, cl->F, q->V); 571204591Sluigi 572204591Sluigi if (qfq_update_class(q, grp, cl)) { 573204591Sluigi uint64_t old_F = grp->F; 574204591Sluigi cl = qfq_slot_scan(grp); 575204591Sluigi if (!cl) { /* group gone, remove from ER */ 576204591Sluigi __clear_bit(grp->index, &q->bitmaps[ER]); 577204591Sluigi // grp->S = grp->F + 1; // XXX debugging only 578204591Sluigi } else { 579204591Sluigi uint64_t roundedS = qfq_round_down(cl->S, grp->slot_shift); 580204591Sluigi unsigned int s; 581204591Sluigi 582204591Sluigi if (grp->S == roundedS) 583204591Sluigi goto skip_unblock; 584204591Sluigi grp->S = roundedS; 585204591Sluigi grp->F = roundedS + (2ULL << grp->slot_shift); 586204591Sluigi /* remove from ER and put in the new set */ 587204591Sluigi __clear_bit(grp->index, &q->bitmaps[ER]); 588204591Sluigi s = qfq_calc_state(q, grp); 589204591Sluigi __set_bit(grp->index, &q->bitmaps[s]); 590204591Sluigi } 591204591Sluigi /* we need to unblock even if the group has gone away */ 592204591Sluigi qfq_unblock_groups(q, grp->index, old_F); 593204591Sluigi } 594204591Sluigi 595204591Sluigiskip_unblock: 596204591Sluigi qfq_update_eligible(q, old_V); 597204591Sluigi NO(if (!q->bitmaps[ER] && q->queued) 598204591Sluigi dump_sched(q, "end dequeue");) 599204591Sluigi 600204591Sluigi return m; 601204591Sluigi} 602204591Sluigi 603204591Sluigi/* 604204591Sluigi * Assign a reasonable start time for a new flow k in group i. 605204591Sluigi * Admissible values for \hat(F) are multiples of \sigma_i 606204591Sluigi * no greater than V+\sigma_i . Larger values mean that 607204591Sluigi * we had a wraparound so we consider the timestamp to be stale. 608204591Sluigi * 609204591Sluigi * If F is not stale and F >= V then we set S = F. 610204591Sluigi * Otherwise we should assign S = V, but this may violate 611204591Sluigi * the ordering in ER. So, if we have groups in ER, set S to 612204591Sluigi * the F_j of the first group j which would be blocking us. 613204591Sluigi * We are guaranteed not to move S backward because 614204591Sluigi * otherwise our group i would still be blocked. 615204591Sluigi */ 616204591Sluigistatic inline void 617204591Sluigiqfq_update_start(struct qfq_sched *q, struct qfq_class *cl) 618204591Sluigi{ 619204591Sluigi unsigned long mask; 620230614Sluigi uint64_t limit, roundedF; 621204591Sluigi int slot_shift = cl->grp->slot_shift; 622204591Sluigi 623204591Sluigi roundedF = qfq_round_down(cl->F, slot_shift); 624285362Sluigi limit = qfq_round_down(q->V, slot_shift) + (1ULL << slot_shift); 625204591Sluigi 626204591Sluigi if (!qfq_gt(cl->F, q->V) || qfq_gt(roundedF, limit)) { 627204591Sluigi /* timestamp was stale */ 628204591Sluigi mask = mask_from(q->bitmaps[ER], cl->grp->index); 629204591Sluigi if (mask) { 630204591Sluigi struct qfq_group *next = qfq_ffs(q, mask); 631204591Sluigi if (qfq_gt(roundedF, next->F)) { 632285362Sluigi /* from pv 71261956973ba9e0637848a5adb4a5819b4bae83 */ 633285362Sluigi if (qfq_gt(limit, next->F)) 634285362Sluigi cl->S = next->F; 635285362Sluigi else /* preserve timestamp correctness */ 636285362Sluigi cl->S = limit; 637204591Sluigi return; 638204591Sluigi } 639204591Sluigi } 640204591Sluigi cl->S = q->V; 641204591Sluigi } else { /* timestamp is not stale */ 642204591Sluigi cl->S = cl->F; 643204591Sluigi } 644204591Sluigi} 645204591Sluigi 646204591Sluigistatic int 647204591Sluigiqfq_enqueue(struct dn_sch_inst *si, struct dn_queue *_q, struct mbuf *m) 648204591Sluigi{ 649204591Sluigi struct qfq_sched *q = (struct qfq_sched *)(si + 1); 650204591Sluigi struct qfq_group *grp; 651204591Sluigi struct qfq_class *cl = (struct qfq_class *)_q; 652204591Sluigi uint64_t roundedS; 653204591Sluigi int s; 654204591Sluigi 655204591Sluigi NO(q->loops++;) 656204591Sluigi DX(4, "len %d flow %p inv_w 0x%x grp %d", m->m_pkthdr.len, 657204591Sluigi _q, cl->inv_w, cl->grp->index); 658204591Sluigi /* XXX verify that the packet obeys the parameters */ 659204591Sluigi if (m != _q->mq.head) { 660204591Sluigi if (dn_enqueue(_q, m, 0)) /* packet was dropped */ 661204591Sluigi return 1; 662204591Sluigi NO(q->queued++;) 663204591Sluigi if (m != _q->mq.head) 664204591Sluigi return 0; 665204591Sluigi } 666204591Sluigi /* If reach this point, queue q was idle */ 667204591Sluigi grp = cl->grp; 668204591Sluigi qfq_update_start(q, cl); /* adjust start time */ 669204591Sluigi /* compute new finish time and rounded start. */ 670204591Sluigi cl->F = cl->S + (uint64_t)(m->m_pkthdr.len) * cl->inv_w; 671204591Sluigi roundedS = qfq_round_down(cl->S, grp->slot_shift); 672204591Sluigi 673204591Sluigi /* 674204591Sluigi * insert cl in the correct bucket. 675204591Sluigi * If cl->S >= grp->S we don't need to adjust the 676204591Sluigi * bucket list and simply go to the insertion phase. 677204591Sluigi * Otherwise grp->S is decreasing, we must make room 678204591Sluigi * in the bucket list, and also recompute the group state. 679204591Sluigi * Finally, if there were no flows in this group and nobody 680204591Sluigi * was in ER make sure to adjust V. 681204591Sluigi */ 682204591Sluigi if (grp->full_slots) { 683204591Sluigi if (!qfq_gt(grp->S, cl->S)) 684204591Sluigi goto skip_update; 685204591Sluigi /* create a slot for this cl->S */ 686204591Sluigi qfq_slot_rotate(q, grp, roundedS); 687204591Sluigi /* group was surely ineligible, remove */ 688204591Sluigi __clear_bit(grp->index, &q->bitmaps[IR]); 689204591Sluigi __clear_bit(grp->index, &q->bitmaps[IB]); 690204591Sluigi } else if (!q->bitmaps[ER] && qfq_gt(roundedS, q->V)) 691204591Sluigi q->V = roundedS; 692204591Sluigi 693204591Sluigi grp->S = roundedS; 694204591Sluigi grp->F = roundedS + (2ULL << grp->slot_shift); // i.e. 2\sigma_i 695204591Sluigi s = qfq_calc_state(q, grp); 696204591Sluigi __set_bit(grp->index, &q->bitmaps[s]); 697204591Sluigi ND("new state %d 0x%x", s, q->bitmaps[s]); 698204591Sluigi ND("S %llx F %llx V %llx", cl->S, cl->F, q->V); 699204591Sluigiskip_update: 700204591Sluigi qfq_slot_insert(grp, cl, roundedS); 701204591Sluigi 702204591Sluigi return 0; 703204591Sluigi} 704204591Sluigi 705204591Sluigi 706204591Sluigi#if 0 707204591Sluigistatic inline void 708204591Sluigiqfq_slot_remove(struct qfq_sched *q, struct qfq_group *grp, 709204591Sluigi struct qfq_class *cl, struct qfq_class **pprev) 710204591Sluigi{ 711204591Sluigi unsigned int i, offset; 712204591Sluigi uint64_t roundedS; 713204591Sluigi 714204591Sluigi roundedS = qfq_round_down(cl->S, grp->slot_shift); 715204591Sluigi offset = (roundedS - grp->S) >> grp->slot_shift; 716204591Sluigi i = (grp->front + offset) % QFQ_MAX_SLOTS; 717204591Sluigi 718204591Sluigi#ifdef notyet 719204591Sluigi if (!pprev) { 720204591Sluigi pprev = &grp->slots[i]; 721204591Sluigi while (*pprev && *pprev != cl) 722204591Sluigi pprev = &(*pprev)->next; 723204591Sluigi } 724204591Sluigi#endif 725204591Sluigi 726204591Sluigi *pprev = cl->next; 727204591Sluigi if (!grp->slots[i]) 728204591Sluigi __clear_bit(offset, &grp->full_slots); 729204591Sluigi} 730204591Sluigi 731204591Sluigi/* 732204591Sluigi * called to forcibly destroy a queue. 733204591Sluigi * If the queue is not in the front bucket, or if it has 734204591Sluigi * other queues in the front bucket, we can simply remove 735204591Sluigi * the queue with no other side effects. 736204591Sluigi * Otherwise we must propagate the event up. 737204591Sluigi * XXX description to be completed. 738204591Sluigi */ 739204591Sluigistatic void 740204591Sluigiqfq_deactivate_class(struct qfq_sched *q, struct qfq_class *cl, 741204591Sluigi struct qfq_class **pprev) 742204591Sluigi{ 743204591Sluigi struct qfq_group *grp = &q->groups[cl->index]; 744204591Sluigi unsigned long mask; 745204591Sluigi uint64_t roundedS; 746204591Sluigi int s; 747204591Sluigi 748204591Sluigi cl->F = cl->S; // not needed if the class goes away. 749204591Sluigi qfq_slot_remove(q, grp, cl, pprev); 750204591Sluigi 751204591Sluigi if (!grp->full_slots) { 752204591Sluigi /* nothing left in the group, remove from all sets. 753204591Sluigi * Do ER last because if we were blocking other groups 754204591Sluigi * we must unblock them. 755204591Sluigi */ 756204591Sluigi __clear_bit(grp->index, &q->bitmaps[IR]); 757204591Sluigi __clear_bit(grp->index, &q->bitmaps[EB]); 758204591Sluigi __clear_bit(grp->index, &q->bitmaps[IB]); 759204591Sluigi 760204591Sluigi if (test_bit(grp->index, &q->bitmaps[ER]) && 761204591Sluigi !(q->bitmaps[ER] & ~((1UL << grp->index) - 1))) { 762204591Sluigi mask = q->bitmaps[ER] & ((1UL << grp->index) - 1); 763204591Sluigi if (mask) 764204591Sluigi mask = ~((1UL << __fls(mask)) - 1); 765204591Sluigi else 766204591Sluigi mask = ~0UL; 767204591Sluigi qfq_move_groups(q, mask, EB, ER); 768204591Sluigi qfq_move_groups(q, mask, IB, IR); 769204591Sluigi } 770204591Sluigi __clear_bit(grp->index, &q->bitmaps[ER]); 771204591Sluigi } else if (!grp->slots[grp->front]) { 772204591Sluigi cl = qfq_slot_scan(grp); 773204591Sluigi roundedS = qfq_round_down(cl->S, grp->slot_shift); 774204591Sluigi if (grp->S != roundedS) { 775204591Sluigi __clear_bit(grp->index, &q->bitmaps[ER]); 776204591Sluigi __clear_bit(grp->index, &q->bitmaps[IR]); 777204591Sluigi __clear_bit(grp->index, &q->bitmaps[EB]); 778204591Sluigi __clear_bit(grp->index, &q->bitmaps[IB]); 779204591Sluigi grp->S = roundedS; 780204591Sluigi grp->F = roundedS + (2ULL << grp->slot_shift); 781204591Sluigi s = qfq_calc_state(q, grp); 782204591Sluigi __set_bit(grp->index, &q->bitmaps[s]); 783204591Sluigi } 784204591Sluigi } 785204591Sluigi qfq_update_eligible(q, q->V); 786204591Sluigi} 787204591Sluigi#endif 788204591Sluigi 789204591Sluigistatic int 790204591Sluigiqfq_new_fsk(struct dn_fsk *f) 791204591Sluigi{ 792204591Sluigi ipdn_bound_var(&f->fs.par[0], 1, 1, QFQ_MAX_WEIGHT, "qfq weight"); 793204591Sluigi ipdn_bound_var(&f->fs.par[1], 1500, 1, 2000, "qfq maxlen"); 794204591Sluigi ND("weight %d len %d\n", f->fs.par[0], f->fs.par[1]); 795204591Sluigi return 0; 796204591Sluigi} 797204591Sluigi 798204591Sluigi/* 799204591Sluigi * initialize a new scheduler instance 800204591Sluigi */ 801204591Sluigistatic int 802204591Sluigiqfq_new_sched(struct dn_sch_inst *si) 803204591Sluigi{ 804204591Sluigi struct qfq_sched *q = (struct qfq_sched *)(si + 1); 805204591Sluigi struct qfq_group *grp; 806204591Sluigi int i; 807204591Sluigi 808204591Sluigi for (i = 0; i <= QFQ_MAX_INDEX; i++) { 809204591Sluigi grp = &q->groups[i]; 810204591Sluigi grp->index = i; 811204591Sluigi grp->slot_shift = QFQ_MTU_SHIFT + FRAC_BITS - 812204591Sluigi (QFQ_MAX_INDEX - i); 813204591Sluigi } 814204591Sluigi return 0; 815204591Sluigi} 816204591Sluigi 817204591Sluigi/* 818204591Sluigi * QFQ scheduler descriptor 819204591Sluigi */ 820204591Sluigistatic struct dn_alg qfq_desc = { 821204591Sluigi _SI( .type = ) DN_SCHED_QFQ, 822204591Sluigi _SI( .name = ) "QFQ", 823204591Sluigi _SI( .flags = ) DN_MULTIQUEUE, 824204591Sluigi 825204591Sluigi _SI( .schk_datalen = ) 0, 826204591Sluigi _SI( .si_datalen = ) sizeof(struct qfq_sched), 827204591Sluigi _SI( .q_datalen = ) sizeof(struct qfq_class) - sizeof(struct dn_queue), 828204591Sluigi 829204591Sluigi _SI( .enqueue = ) qfq_enqueue, 830204591Sluigi _SI( .dequeue = ) qfq_dequeue, 831204591Sluigi 832204591Sluigi _SI( .config = ) NULL, 833204591Sluigi _SI( .destroy = ) NULL, 834204591Sluigi _SI( .new_sched = ) qfq_new_sched, 835204591Sluigi _SI( .free_sched = ) NULL, 836204591Sluigi _SI( .new_fsk = ) qfq_new_fsk, 837204591Sluigi _SI( .free_fsk = ) NULL, 838204591Sluigi _SI( .new_queue = ) qfq_new_queue, 839204591Sluigi _SI( .free_queue = ) qfq_free_queue, 840204591Sluigi}; 841204591Sluigi 842204591SluigiDECLARE_DNSCHED_MODULE(dn_qfq, &qfq_desc); 843204591Sluigi 844204591Sluigi#ifdef QFQ_DEBUG 845204591Sluigistatic void 846204591Sluigidump_groups(struct qfq_sched *q, uint32_t mask) 847204591Sluigi{ 848204591Sluigi int i, j; 849204591Sluigi 850204591Sluigi for (i = 0; i < QFQ_MAX_INDEX + 1; i++) { 851204591Sluigi struct qfq_group *g = &q->groups[i]; 852204591Sluigi 853204591Sluigi if (0 == (mask & (1<<i))) 854204591Sluigi continue; 855204591Sluigi for (j = 0; j < QFQ_MAX_SLOTS; j++) { 856204591Sluigi if (g->slots[j]) 857204591Sluigi D(" bucket %d %p", j, g->slots[j]); 858204591Sluigi } 859294858Sluigi D("full_slots 0x%llx", (_P64)g->full_slots); 860204591Sluigi D(" %2d S 0x%20llx F 0x%llx %c", i, 861294858Sluigi (_P64)g->S, (_P64)g->F, 862204591Sluigi mask & (1<<i) ? '1' : '0'); 863204591Sluigi } 864204591Sluigi} 865204591Sluigi 866204591Sluigistatic void 867204591Sluigidump_sched(struct qfq_sched *q, const char *msg) 868204591Sluigi{ 869204591Sluigi D("--- in %s: ---", msg); 870294858Sluigi D("loops %d queued %d V 0x%llx", q->loops, q->queued, (_P64)q->V); 871294858Sluigi D(" ER 0x%08x", (unsigned)q->bitmaps[ER]); 872294858Sluigi D(" EB 0x%08x", (unsigned)q->bitmaps[EB]); 873294858Sluigi D(" IR 0x%08x", (unsigned)q->bitmaps[IR]); 874294858Sluigi D(" IB 0x%08x", (unsigned)q->bitmaps[IB]); 875204591Sluigi dump_groups(q, 0xffffffff); 876204591Sluigi}; 877204591Sluigi#endif /* QFQ_DEBUG */ 878