Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/sched/sch_sfq.c Stochastic Fairness Queueing discipline. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| 10 | */ |
| 11 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/types.h> |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/jiffies.h> |
| 16 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/in.h> |
| 18 | #include <linux/errno.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/init.h> |
Patrick McHardy | 0ba4805 | 2007-07-02 22:49:07 -0700 | [diff] [blame] | 20 | #include <linux/ipv6.h> |
| 21 | #include <linux/skbuff.h> |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 22 | #include <linux/jhash.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <net/ip.h> |
Arnaldo Carvalho de Melo | dc5fc57 | 2007-03-25 23:06:12 -0700 | [diff] [blame] | 24 | #include <net/netlink.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <net/pkt_sched.h> |
| 26 | |
| 27 | |
| 28 | /* Stochastic Fairness Queuing algorithm. |
| 29 | ======================================= |
| 30 | |
| 31 | Source: |
| 32 | Paul E. McKenney "Stochastic Fairness Queuing", |
| 33 | IEEE INFOCOMM'90 Proceedings, San Francisco, 1990. |
| 34 | |
| 35 | Paul E. McKenney "Stochastic Fairness Queuing", |
| 36 | "Interworking: Research and Experience", v.2, 1991, p.113-131. |
| 37 | |
| 38 | |
| 39 | See also: |
| 40 | M. Shreedhar and George Varghese "Efficient Fair |
| 41 | Queuing using Deficit Round Robin", Proc. SIGCOMM 95. |
| 42 | |
| 43 | |
YOSHIFUJI Hideaki | 10297b9 | 2007-02-09 23:25:16 +0900 | [diff] [blame] | 44 | This is not the thing that is usually called (W)FQ nowadays. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | It does not use any timestamp mechanism, but instead |
| 46 | processes queues in round-robin order. |
| 47 | |
| 48 | ADVANTAGE: |
| 49 | |
| 50 | - It is very cheap. Both CPU and memory requirements are minimal. |
| 51 | |
| 52 | DRAWBACKS: |
| 53 | |
YOSHIFUJI Hideaki | 10297b9 | 2007-02-09 23:25:16 +0900 | [diff] [blame] | 54 | - "Stochastic" -> It is not 100% fair. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | When hash collisions occur, several flows are considered as one. |
| 56 | |
| 57 | - "Round-robin" -> It introduces larger delays than virtual clock |
| 58 | based schemes, and should not be used for isolating interactive |
| 59 | traffic from non-interactive. It means, that this scheduler |
| 60 | should be used as leaf of CBQ or P3, which put interactive traffic |
| 61 | to higher priority band. |
| 62 | |
| 63 | We still need true WFQ for top level CSZ, but using WFQ |
| 64 | for the best effort traffic is absolutely pointless: |
| 65 | SFQ is superior for this purpose. |
| 66 | |
| 67 | IMPLEMENTATION: |
| 68 | This implementation limits maximal queue length to 128; |
| 69 | maximal mtu to 2^15-1; number of hash buckets to 1024. |
| 70 | The only goal of this restrictions was that all data |
| 71 | fit into one 4K page :-). Struct sfq_sched_data is |
| 72 | organized in anti-cache manner: all the data for a bucket |
| 73 | are scattered over different locations. This is not good, |
| 74 | but it allowed me to put it into 4K. |
| 75 | |
| 76 | It is easy to increase these values, but not in flight. */ |
| 77 | |
| 78 | #define SFQ_DEPTH 128 |
| 79 | #define SFQ_HASH_DIVISOR 1024 |
| 80 | |
| 81 | /* This type should contain at least SFQ_DEPTH*2 values */ |
| 82 | typedef unsigned char sfq_index; |
| 83 | |
| 84 | struct sfq_head |
| 85 | { |
| 86 | sfq_index next; |
| 87 | sfq_index prev; |
| 88 | }; |
| 89 | |
| 90 | struct sfq_sched_data |
| 91 | { |
| 92 | /* Parameters */ |
| 93 | int perturb_period; |
| 94 | unsigned quantum; /* Allotment per round: MUST BE >= MTU */ |
| 95 | int limit; |
| 96 | |
| 97 | /* Variables */ |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 98 | struct tcf_proto *filter_list; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | struct timer_list perturb_timer; |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 100 | u32 perturbation; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | sfq_index tail; /* Index of current slot in round */ |
| 102 | sfq_index max_depth; /* Maximal depth */ |
| 103 | |
| 104 | sfq_index ht[SFQ_HASH_DIVISOR]; /* Hash table */ |
| 105 | sfq_index next[SFQ_DEPTH]; /* Active slots link */ |
| 106 | short allot[SFQ_DEPTH]; /* Current allotment per slot */ |
| 107 | unsigned short hash[SFQ_DEPTH]; /* Hash value indexed by slots */ |
| 108 | struct sk_buff_head qs[SFQ_DEPTH]; /* Slot queue */ |
| 109 | struct sfq_head dep[SFQ_DEPTH*2]; /* Linked list of slots, indexed by depth */ |
| 110 | }; |
| 111 | |
| 112 | static __inline__ unsigned sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1) |
| 113 | { |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 114 | return jhash_2words(h, h1, q->perturbation) & (SFQ_HASH_DIVISOR - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | } |
| 116 | |
| 117 | static unsigned sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb) |
| 118 | { |
| 119 | u32 h, h2; |
| 120 | |
| 121 | switch (skb->protocol) { |
| 122 | case __constant_htons(ETH_P_IP): |
| 123 | { |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 124 | const struct iphdr *iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | h = iph->daddr; |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 126 | h2 = iph->saddr ^ iph->protocol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) && |
| 128 | (iph->protocol == IPPROTO_TCP || |
| 129 | iph->protocol == IPPROTO_UDP || |
Patrick McHardy | a8d0f95 | 2007-02-07 15:07:43 -0800 | [diff] [blame] | 130 | iph->protocol == IPPROTO_UDPLITE || |
Patrick McHardy | ae82af5 | 2006-01-17 13:01:06 -0800 | [diff] [blame] | 131 | iph->protocol == IPPROTO_SCTP || |
| 132 | iph->protocol == IPPROTO_DCCP || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | iph->protocol == IPPROTO_ESP)) |
| 134 | h2 ^= *(((u32*)iph) + iph->ihl); |
| 135 | break; |
| 136 | } |
| 137 | case __constant_htons(ETH_P_IPV6): |
| 138 | { |
Arnaldo Carvalho de Melo | 0660e03 | 2007-04-25 17:54:47 -0700 | [diff] [blame] | 139 | struct ipv6hdr *iph = ipv6_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | h = iph->daddr.s6_addr32[3]; |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 141 | h2 = iph->saddr.s6_addr32[3] ^ iph->nexthdr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | if (iph->nexthdr == IPPROTO_TCP || |
| 143 | iph->nexthdr == IPPROTO_UDP || |
Patrick McHardy | a8d0f95 | 2007-02-07 15:07:43 -0800 | [diff] [blame] | 144 | iph->nexthdr == IPPROTO_UDPLITE || |
Patrick McHardy | ae82af5 | 2006-01-17 13:01:06 -0800 | [diff] [blame] | 145 | iph->nexthdr == IPPROTO_SCTP || |
| 146 | iph->nexthdr == IPPROTO_DCCP || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | iph->nexthdr == IPPROTO_ESP) |
| 148 | h2 ^= *(u32*)&iph[1]; |
| 149 | break; |
| 150 | } |
| 151 | default: |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 152 | h = (unsigned long)skb->dst ^ skb->protocol; |
| 153 | h2 = (unsigned long)skb->sk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | return sfq_fold_hash(q, h, h2); |
| 157 | } |
| 158 | |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 159 | static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch, |
| 160 | int *qerr) |
| 161 | { |
| 162 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 163 | struct tcf_result res; |
| 164 | int result; |
| 165 | |
| 166 | if (TC_H_MAJ(skb->priority) == sch->handle && |
| 167 | TC_H_MIN(skb->priority) > 0 && |
| 168 | TC_H_MIN(skb->priority) <= SFQ_HASH_DIVISOR) |
| 169 | return TC_H_MIN(skb->priority); |
| 170 | |
| 171 | if (!q->filter_list) |
| 172 | return sfq_hash(q, skb) + 1; |
| 173 | |
| 174 | *qerr = NET_XMIT_BYPASS; |
| 175 | result = tc_classify(skb, q->filter_list, &res); |
| 176 | if (result >= 0) { |
| 177 | #ifdef CONFIG_NET_CLS_ACT |
| 178 | switch (result) { |
| 179 | case TC_ACT_STOLEN: |
| 180 | case TC_ACT_QUEUED: |
| 181 | *qerr = NET_XMIT_SUCCESS; |
| 182 | case TC_ACT_SHOT: |
| 183 | return 0; |
| 184 | } |
| 185 | #endif |
| 186 | if (TC_H_MIN(res.classid) <= SFQ_HASH_DIVISOR) |
| 187 | return TC_H_MIN(res.classid); |
| 188 | } |
| 189 | return 0; |
| 190 | } |
| 191 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | static inline void sfq_link(struct sfq_sched_data *q, sfq_index x) |
| 193 | { |
| 194 | sfq_index p, n; |
| 195 | int d = q->qs[x].qlen + SFQ_DEPTH; |
| 196 | |
| 197 | p = d; |
| 198 | n = q->dep[d].next; |
| 199 | q->dep[x].next = n; |
| 200 | q->dep[x].prev = p; |
| 201 | q->dep[p].next = q->dep[n].prev = x; |
| 202 | } |
| 203 | |
| 204 | static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x) |
| 205 | { |
| 206 | sfq_index p, n; |
| 207 | |
| 208 | n = q->dep[x].next; |
| 209 | p = q->dep[x].prev; |
| 210 | q->dep[p].next = n; |
| 211 | q->dep[n].prev = p; |
| 212 | |
| 213 | if (n == p && q->max_depth == q->qs[x].qlen + 1) |
| 214 | q->max_depth--; |
| 215 | |
| 216 | sfq_link(q, x); |
| 217 | } |
| 218 | |
| 219 | static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x) |
| 220 | { |
| 221 | sfq_index p, n; |
| 222 | int d; |
| 223 | |
| 224 | n = q->dep[x].next; |
| 225 | p = q->dep[x].prev; |
| 226 | q->dep[p].next = n; |
| 227 | q->dep[n].prev = p; |
| 228 | d = q->qs[x].qlen; |
| 229 | if (q->max_depth < d) |
| 230 | q->max_depth = d; |
| 231 | |
| 232 | sfq_link(q, x); |
| 233 | } |
| 234 | |
| 235 | static unsigned int sfq_drop(struct Qdisc *sch) |
| 236 | { |
| 237 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 238 | sfq_index d = q->max_depth; |
| 239 | struct sk_buff *skb; |
| 240 | unsigned int len; |
| 241 | |
| 242 | /* Queue is full! Find the longest slot and |
| 243 | drop a packet from it */ |
| 244 | |
| 245 | if (d > 1) { |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 246 | sfq_index x = q->dep[d + SFQ_DEPTH].next; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | skb = q->qs[x].prev; |
| 248 | len = skb->len; |
| 249 | __skb_unlink(skb, &q->qs[x]); |
| 250 | kfree_skb(skb); |
| 251 | sfq_dec(q, x); |
| 252 | sch->q.qlen--; |
| 253 | sch->qstats.drops++; |
Patrick McHardy | f5539eb | 2006-03-20 19:01:38 -0800 | [diff] [blame] | 254 | sch->qstats.backlog -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | return len; |
| 256 | } |
| 257 | |
| 258 | if (d == 1) { |
| 259 | /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ |
| 260 | d = q->next[q->tail]; |
| 261 | q->next[q->tail] = q->next[d]; |
| 262 | q->allot[q->next[d]] += q->quantum; |
| 263 | skb = q->qs[d].prev; |
| 264 | len = skb->len; |
| 265 | __skb_unlink(skb, &q->qs[d]); |
| 266 | kfree_skb(skb); |
| 267 | sfq_dec(q, d); |
| 268 | sch->q.qlen--; |
| 269 | q->ht[q->hash[d]] = SFQ_DEPTH; |
| 270 | sch->qstats.drops++; |
Patrick McHardy | f5539eb | 2006-03-20 19:01:38 -0800 | [diff] [blame] | 271 | sch->qstats.backlog -= len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | return len; |
| 273 | } |
| 274 | |
| 275 | return 0; |
| 276 | } |
| 277 | |
| 278 | static int |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 279 | sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | { |
| 281 | struct sfq_sched_data *q = qdisc_priv(sch); |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 282 | unsigned int hash; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | sfq_index x; |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 284 | int ret; |
| 285 | |
| 286 | hash = sfq_classify(skb, sch, &ret); |
| 287 | if (hash == 0) { |
| 288 | if (ret == NET_XMIT_BYPASS) |
| 289 | sch->qstats.drops++; |
| 290 | kfree_skb(skb); |
| 291 | return ret; |
| 292 | } |
| 293 | hash--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | |
| 295 | x = q->ht[hash]; |
| 296 | if (x == SFQ_DEPTH) { |
| 297 | q->ht[hash] = x = q->dep[SFQ_DEPTH].next; |
| 298 | q->hash[x] = hash; |
| 299 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 300 | |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 301 | /* If selected queue has length q->limit, this means that |
| 302 | * all another queues are empty and that we do simple tail drop, |
| 303 | * i.e. drop _this_ packet. |
| 304 | */ |
| 305 | if (q->qs[x].qlen >= q->limit) |
| 306 | return qdisc_drop(skb, sch); |
| 307 | |
Patrick McHardy | f5539eb | 2006-03-20 19:01:38 -0800 | [diff] [blame] | 308 | sch->qstats.backlog += skb->len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | __skb_queue_tail(&q->qs[x], skb); |
| 310 | sfq_inc(q, x); |
| 311 | if (q->qs[x].qlen == 1) { /* The flow is new */ |
| 312 | if (q->tail == SFQ_DEPTH) { /* It is the first flow */ |
| 313 | q->tail = x; |
| 314 | q->next[x] = x; |
| 315 | q->allot[x] = q->quantum; |
| 316 | } else { |
| 317 | q->next[x] = q->next[q->tail]; |
| 318 | q->next[q->tail] = x; |
| 319 | q->tail = x; |
| 320 | } |
| 321 | } |
Alexey Kuznetsov | 5588b40 | 2007-09-19 10:42:03 -0700 | [diff] [blame] | 322 | if (++sch->q.qlen <= q->limit) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | sch->bstats.bytes += skb->len; |
| 324 | sch->bstats.packets++; |
| 325 | return 0; |
| 326 | } |
| 327 | |
| 328 | sfq_drop(sch); |
| 329 | return NET_XMIT_CN; |
| 330 | } |
| 331 | |
| 332 | static int |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 333 | sfq_requeue(struct sk_buff *skb, struct Qdisc *sch) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | { |
| 335 | struct sfq_sched_data *q = qdisc_priv(sch); |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 336 | unsigned int hash; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | sfq_index x; |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 338 | int ret; |
| 339 | |
| 340 | hash = sfq_classify(skb, sch, &ret); |
| 341 | if (hash == 0) { |
| 342 | if (ret == NET_XMIT_BYPASS) |
| 343 | sch->qstats.drops++; |
| 344 | kfree_skb(skb); |
| 345 | return ret; |
| 346 | } |
| 347 | hash--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | |
| 349 | x = q->ht[hash]; |
| 350 | if (x == SFQ_DEPTH) { |
| 351 | q->ht[hash] = x = q->dep[SFQ_DEPTH].next; |
| 352 | q->hash[x] = hash; |
| 353 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 354 | |
Patrick McHardy | f5539eb | 2006-03-20 19:01:38 -0800 | [diff] [blame] | 355 | sch->qstats.backlog += skb->len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | __skb_queue_head(&q->qs[x], skb); |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 357 | /* If selected queue has length q->limit+1, this means that |
| 358 | * all another queues are empty and we do simple tail drop. |
| 359 | * This packet is still requeued at head of queue, tail packet |
| 360 | * is dropped. |
| 361 | */ |
| 362 | if (q->qs[x].qlen > q->limit) { |
| 363 | skb = q->qs[x].prev; |
| 364 | __skb_unlink(skb, &q->qs[x]); |
| 365 | sch->qstats.drops++; |
| 366 | sch->qstats.backlog -= skb->len; |
| 367 | kfree_skb(skb); |
| 368 | return NET_XMIT_CN; |
| 369 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 370 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | sfq_inc(q, x); |
| 372 | if (q->qs[x].qlen == 1) { /* The flow is new */ |
| 373 | if (q->tail == SFQ_DEPTH) { /* It is the first flow */ |
| 374 | q->tail = x; |
| 375 | q->next[x] = x; |
| 376 | q->allot[x] = q->quantum; |
| 377 | } else { |
| 378 | q->next[x] = q->next[q->tail]; |
| 379 | q->next[q->tail] = x; |
| 380 | q->tail = x; |
| 381 | } |
| 382 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 383 | |
Alexey Kuznetsov | 5588b40 | 2007-09-19 10:42:03 -0700 | [diff] [blame] | 384 | if (++sch->q.qlen <= q->limit) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | sch->qstats.requeues++; |
| 386 | return 0; |
| 387 | } |
| 388 | |
| 389 | sch->qstats.drops++; |
| 390 | sfq_drop(sch); |
| 391 | return NET_XMIT_CN; |
| 392 | } |
| 393 | |
| 394 | |
| 395 | |
| 396 | |
| 397 | static struct sk_buff * |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 398 | sfq_dequeue(struct Qdisc *sch) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 399 | { |
| 400 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 401 | struct sk_buff *skb; |
| 402 | sfq_index a, old_a; |
| 403 | |
| 404 | /* No active slots */ |
| 405 | if (q->tail == SFQ_DEPTH) |
| 406 | return NULL; |
| 407 | |
| 408 | a = old_a = q->next[q->tail]; |
| 409 | |
| 410 | /* Grab packet */ |
| 411 | skb = __skb_dequeue(&q->qs[a]); |
| 412 | sfq_dec(q, a); |
| 413 | sch->q.qlen--; |
Patrick McHardy | f5539eb | 2006-03-20 19:01:38 -0800 | [diff] [blame] | 414 | sch->qstats.backlog -= skb->len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | |
| 416 | /* Is the slot empty? */ |
| 417 | if (q->qs[a].qlen == 0) { |
| 418 | q->ht[q->hash[a]] = SFQ_DEPTH; |
| 419 | a = q->next[a]; |
| 420 | if (a == old_a) { |
| 421 | q->tail = SFQ_DEPTH; |
| 422 | return skb; |
| 423 | } |
| 424 | q->next[q->tail] = a; |
| 425 | q->allot[a] += q->quantum; |
| 426 | } else if ((q->allot[a] -= skb->len) <= 0) { |
| 427 | q->tail = a; |
| 428 | a = q->next[a]; |
| 429 | q->allot[a] += q->quantum; |
| 430 | } |
| 431 | return skb; |
| 432 | } |
| 433 | |
| 434 | static void |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 435 | sfq_reset(struct Qdisc *sch) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | { |
| 437 | struct sk_buff *skb; |
| 438 | |
| 439 | while ((skb = sfq_dequeue(sch)) != NULL) |
| 440 | kfree_skb(skb); |
| 441 | } |
| 442 | |
| 443 | static void sfq_perturbation(unsigned long arg) |
| 444 | { |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 445 | struct Qdisc *sch = (struct Qdisc *)arg; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 447 | |
Stephen Hemminger | d46f8dd | 2008-01-20 17:19:43 -0800 | [diff] [blame] | 448 | q->perturbation = net_random(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 450 | if (q->perturb_period) |
| 451 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | } |
| 453 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 454 | static int sfq_change(struct Qdisc *sch, struct nlattr *opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | { |
| 456 | struct sfq_sched_data *q = qdisc_priv(sch); |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 457 | struct tc_sfq_qopt *ctl = nla_data(opt); |
Patrick McHardy | 5e50da0 | 2006-11-29 17:36:20 -0800 | [diff] [blame] | 458 | unsigned int qlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 460 | if (opt->nla_len < nla_attr_size(sizeof(*ctl))) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | return -EINVAL; |
| 462 | |
| 463 | sch_tree_lock(sch); |
| 464 | q->quantum = ctl->quantum ? : psched_mtu(sch->dev); |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 465 | q->perturb_period = ctl->perturb_period * HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | if (ctl->limit) |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 467 | q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
Patrick McHardy | 5e50da0 | 2006-11-29 17:36:20 -0800 | [diff] [blame] | 469 | qlen = sch->q.qlen; |
Alexey Kuznetsov | 5588b40 | 2007-09-19 10:42:03 -0700 | [diff] [blame] | 470 | while (sch->q.qlen > q->limit) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | sfq_drop(sch); |
Patrick McHardy | 5e50da0 | 2006-11-29 17:36:20 -0800 | [diff] [blame] | 472 | qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | del_timer(&q->perturb_timer); |
| 475 | if (q->perturb_period) { |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 476 | mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
Stephen Hemminger | d46f8dd | 2008-01-20 17:19:43 -0800 | [diff] [blame] | 477 | q->perturbation = net_random(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | } |
| 479 | sch_tree_unlock(sch); |
| 480 | return 0; |
| 481 | } |
| 482 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 483 | static int sfq_init(struct Qdisc *sch, struct nlattr *opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | { |
| 485 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 486 | int i; |
| 487 | |
Stephen Hemminger | d3e9948 | 2008-01-20 17:18:45 -0800 | [diff] [blame] | 488 | q->perturb_timer.function = sfq_perturbation; |
| 489 | q->perturb_timer.data = (unsigned long)sch;; |
| 490 | init_timer_deferrable(&q->perturb_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 492 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | q->ht[i] = SFQ_DEPTH; |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 494 | |
| 495 | for (i = 0; i < SFQ_DEPTH; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | skb_queue_head_init(&q->qs[i]); |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 497 | q->dep[i + SFQ_DEPTH].next = i + SFQ_DEPTH; |
| 498 | q->dep[i + SFQ_DEPTH].prev = i + SFQ_DEPTH; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 500 | |
Alexey Kuznetsov | 32740dd | 2007-09-30 17:51:33 -0700 | [diff] [blame] | 501 | q->limit = SFQ_DEPTH - 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | q->max_depth = 0; |
| 503 | q->tail = SFQ_DEPTH; |
| 504 | if (opt == NULL) { |
| 505 | q->quantum = psched_mtu(sch->dev); |
| 506 | q->perturb_period = 0; |
Stephen Hemminger | d46f8dd | 2008-01-20 17:19:43 -0800 | [diff] [blame] | 507 | q->perturbation = net_random(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | } else { |
| 509 | int err = sfq_change(sch, opt); |
| 510 | if (err) |
| 511 | return err; |
| 512 | } |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 513 | |
| 514 | for (i = 0; i < SFQ_DEPTH; i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | sfq_link(q, i); |
| 516 | return 0; |
| 517 | } |
| 518 | |
| 519 | static void sfq_destroy(struct Qdisc *sch) |
| 520 | { |
| 521 | struct sfq_sched_data *q = qdisc_priv(sch); |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 522 | |
| 523 | tcf_destroy_chain(q->filter_list); |
Jarek Poplawski | 980c478 | 2008-04-29 03:29:03 -0700 | [diff] [blame^] | 524 | q->perturb_period = 0; |
| 525 | del_timer_sync(&q->perturb_timer); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | } |
| 527 | |
| 528 | static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb) |
| 529 | { |
| 530 | struct sfq_sched_data *q = qdisc_priv(sch); |
Arnaldo Carvalho de Melo | 27a884d | 2007-04-19 20:29:13 -0700 | [diff] [blame] | 531 | unsigned char *b = skb_tail_pointer(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | struct tc_sfq_qopt opt; |
| 533 | |
| 534 | opt.quantum = q->quantum; |
Stephen Hemminger | 6f9e98f | 2008-01-20 17:20:56 -0800 | [diff] [blame] | 535 | opt.perturb_period = q->perturb_period / HZ; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | |
| 537 | opt.limit = q->limit; |
| 538 | opt.divisor = SFQ_HASH_DIVISOR; |
| 539 | opt.flows = q->limit; |
| 540 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 541 | NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | |
| 543 | return skb->len; |
| 544 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 545 | nla_put_failure: |
Arnaldo Carvalho de Melo | dc5fc57 | 2007-03-25 23:06:12 -0700 | [diff] [blame] | 546 | nlmsg_trim(skb, b); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | return -1; |
| 548 | } |
| 549 | |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 550 | static int sfq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, |
| 551 | struct nlattr **tca, unsigned long *arg) |
| 552 | { |
| 553 | return -EOPNOTSUPP; |
| 554 | } |
| 555 | |
| 556 | static unsigned long sfq_get(struct Qdisc *sch, u32 classid) |
| 557 | { |
| 558 | return 0; |
| 559 | } |
| 560 | |
| 561 | static struct tcf_proto **sfq_find_tcf(struct Qdisc *sch, unsigned long cl) |
| 562 | { |
| 563 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 564 | |
| 565 | if (cl) |
| 566 | return NULL; |
| 567 | return &q->filter_list; |
| 568 | } |
| 569 | |
Patrick McHardy | 94de78d | 2008-01-31 18:37:16 -0800 | [diff] [blame] | 570 | static int sfq_dump_class(struct Qdisc *sch, unsigned long cl, |
| 571 | struct sk_buff *skb, struct tcmsg *tcm) |
| 572 | { |
| 573 | tcm->tcm_handle |= TC_H_MIN(cl); |
| 574 | return 0; |
| 575 | } |
| 576 | |
| 577 | static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl, |
| 578 | struct gnet_dump *d) |
| 579 | { |
| 580 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 581 | sfq_index idx = q->ht[cl-1]; |
| 582 | struct gnet_stats_queue qs = { .qlen = q->qs[idx].qlen }; |
| 583 | struct tc_sfq_xstats xstats = { .allot = q->allot[idx] }; |
| 584 | |
| 585 | if (gnet_stats_copy_queue(d, &qs) < 0) |
| 586 | return -1; |
| 587 | return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); |
| 588 | } |
| 589 | |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 590 | static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
| 591 | { |
Patrick McHardy | 94de78d | 2008-01-31 18:37:16 -0800 | [diff] [blame] | 592 | struct sfq_sched_data *q = qdisc_priv(sch); |
| 593 | unsigned int i; |
| 594 | |
| 595 | if (arg->stop) |
| 596 | return; |
| 597 | |
| 598 | for (i = 0; i < SFQ_HASH_DIVISOR; i++) { |
| 599 | if (q->ht[i] == SFQ_DEPTH || |
| 600 | arg->count < arg->skip) { |
| 601 | arg->count++; |
| 602 | continue; |
| 603 | } |
| 604 | if (arg->fn(sch, i + 1, arg) < 0) { |
| 605 | arg->stop = 1; |
| 606 | break; |
| 607 | } |
| 608 | arg->count++; |
| 609 | } |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 610 | } |
| 611 | |
| 612 | static const struct Qdisc_class_ops sfq_class_ops = { |
| 613 | .get = sfq_get, |
| 614 | .change = sfq_change_class, |
| 615 | .tcf_chain = sfq_find_tcf, |
Patrick McHardy | 94de78d | 2008-01-31 18:37:16 -0800 | [diff] [blame] | 616 | .dump = sfq_dump_class, |
| 617 | .dump_stats = sfq_dump_class_stats, |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 618 | .walk = sfq_walk, |
| 619 | }; |
| 620 | |
Eric Dumazet | 20fea08 | 2007-11-14 01:44:41 -0800 | [diff] [blame] | 621 | static struct Qdisc_ops sfq_qdisc_ops __read_mostly = { |
Patrick McHardy | 7d2681a | 2008-01-31 18:36:52 -0800 | [diff] [blame] | 622 | .cl_ops = &sfq_class_ops, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | .id = "sfq", |
| 624 | .priv_size = sizeof(struct sfq_sched_data), |
| 625 | .enqueue = sfq_enqueue, |
| 626 | .dequeue = sfq_dequeue, |
| 627 | .requeue = sfq_requeue, |
| 628 | .drop = sfq_drop, |
| 629 | .init = sfq_init, |
| 630 | .reset = sfq_reset, |
| 631 | .destroy = sfq_destroy, |
| 632 | .change = NULL, |
| 633 | .dump = sfq_dump, |
| 634 | .owner = THIS_MODULE, |
| 635 | }; |
| 636 | |
| 637 | static int __init sfq_module_init(void) |
| 638 | { |
| 639 | return register_qdisc(&sfq_qdisc_ops); |
| 640 | } |
YOSHIFUJI Hideaki | 10297b9 | 2007-02-09 23:25:16 +0900 | [diff] [blame] | 641 | static void __exit sfq_module_exit(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 642 | { |
| 643 | unregister_qdisc(&sfq_qdisc_ops); |
| 644 | } |
| 645 | module_init(sfq_module_init) |
| 646 | module_exit(sfq_module_exit) |
| 647 | MODULE_LICENSE("GPL"); |