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940 lines
22 KiB
940 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* net/sched/sch_sfq.c Stochastic Fairness Queueing discipline. |
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* |
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* Authors: Alexey Kuznetsov, <[email protected]> |
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*/ |
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|
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/jiffies.h> |
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#include <linux/string.h> |
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#include <linux/in.h> |
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#include <linux/errno.h> |
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#include <linux/init.h> |
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#include <linux/skbuff.h> |
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#include <linux/siphash.h> |
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#include <linux/slab.h> |
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#include <linux/vmalloc.h> |
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#include <net/netlink.h> |
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#include <net/pkt_sched.h> |
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#include <net/pkt_cls.h> |
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#include <net/red.h> |
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/* Stochastic Fairness Queuing algorithm. |
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======================================= |
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|
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Source: |
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Paul E. McKenney "Stochastic Fairness Queuing", |
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IEEE INFOCOMM'90 Proceedings, San Francisco, 1990. |
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|
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Paul E. McKenney "Stochastic Fairness Queuing", |
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"Interworking: Research and Experience", v.2, 1991, p.113-131. |
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See also: |
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M. Shreedhar and George Varghese "Efficient Fair |
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Queuing using Deficit Round Robin", Proc. SIGCOMM 95. |
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This is not the thing that is usually called (W)FQ nowadays. |
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It does not use any timestamp mechanism, but instead |
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processes queues in round-robin order. |
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|
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ADVANTAGE: |
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|
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- It is very cheap. Both CPU and memory requirements are minimal. |
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|
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DRAWBACKS: |
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|
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- "Stochastic" -> It is not 100% fair. |
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When hash collisions occur, several flows are considered as one. |
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|
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- "Round-robin" -> It introduces larger delays than virtual clock |
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based schemes, and should not be used for isolating interactive |
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traffic from non-interactive. It means, that this scheduler |
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should be used as leaf of CBQ or P3, which put interactive traffic |
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to higher priority band. |
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|
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We still need true WFQ for top level CSZ, but using WFQ |
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for the best effort traffic is absolutely pointless: |
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SFQ is superior for this purpose. |
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|
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IMPLEMENTATION: |
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This implementation limits : |
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- maximal queue length per flow to 127 packets. |
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- max mtu to 2^18-1; |
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- max 65408 flows, |
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- number of hash buckets to 65536. |
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|
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It is easy to increase these values, but not in flight. */ |
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|
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#define SFQ_MAX_DEPTH 127 /* max number of packets per flow */ |
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#define SFQ_DEFAULT_FLOWS 128 |
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#define SFQ_MAX_FLOWS (0x10000 - SFQ_MAX_DEPTH - 1) /* max number of flows */ |
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#define SFQ_EMPTY_SLOT 0xffff |
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#define SFQ_DEFAULT_HASH_DIVISOR 1024 |
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|
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/* We use 16 bits to store allot, and want to handle packets up to 64K |
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* Scale allot by 8 (1<<3) so that no overflow occurs. |
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*/ |
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#define SFQ_ALLOT_SHIFT 3 |
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#define SFQ_ALLOT_SIZE(X) DIV_ROUND_UP(X, 1 << SFQ_ALLOT_SHIFT) |
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|
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/* This type should contain at least SFQ_MAX_DEPTH + 1 + SFQ_MAX_FLOWS values */ |
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typedef u16 sfq_index; |
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|
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/* |
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* We dont use pointers to save space. |
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* Small indexes [0 ... SFQ_MAX_FLOWS - 1] are 'pointers' to slots[] array |
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* while following values [SFQ_MAX_FLOWS ... SFQ_MAX_FLOWS + SFQ_MAX_DEPTH] |
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* are 'pointers' to dep[] array |
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*/ |
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struct sfq_head { |
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sfq_index next; |
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sfq_index prev; |
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}; |
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struct sfq_slot { |
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struct sk_buff *skblist_next; |
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struct sk_buff *skblist_prev; |
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sfq_index qlen; /* number of skbs in skblist */ |
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sfq_index next; /* next slot in sfq RR chain */ |
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struct sfq_head dep; /* anchor in dep[] chains */ |
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unsigned short hash; /* hash value (index in ht[]) */ |
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short allot; /* credit for this slot */ |
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|
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unsigned int backlog; |
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struct red_vars vars; |
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}; |
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struct sfq_sched_data { |
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/* frequently used fields */ |
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int limit; /* limit of total number of packets in this qdisc */ |
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unsigned int divisor; /* number of slots in hash table */ |
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u8 headdrop; |
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u8 maxdepth; /* limit of packets per flow */ |
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|
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siphash_key_t perturbation; |
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u8 cur_depth; /* depth of longest slot */ |
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u8 flags; |
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unsigned short scaled_quantum; /* SFQ_ALLOT_SIZE(quantum) */ |
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struct tcf_proto __rcu *filter_list; |
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struct tcf_block *block; |
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sfq_index *ht; /* Hash table ('divisor' slots) */ |
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struct sfq_slot *slots; /* Flows table ('maxflows' entries) */ |
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|
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struct red_parms *red_parms; |
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struct tc_sfqred_stats stats; |
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struct sfq_slot *tail; /* current slot in round */ |
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struct sfq_head dep[SFQ_MAX_DEPTH + 1]; |
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/* Linked lists of slots, indexed by depth |
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* dep[0] : list of unused flows |
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* dep[1] : list of flows with 1 packet |
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* dep[X] : list of flows with X packets |
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*/ |
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unsigned int maxflows; /* number of flows in flows array */ |
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int perturb_period; |
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unsigned int quantum; /* Allotment per round: MUST BE >= MTU */ |
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struct timer_list perturb_timer; |
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struct Qdisc *sch; |
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}; |
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|
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/* |
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* sfq_head are either in a sfq_slot or in dep[] array |
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*/ |
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static inline struct sfq_head *sfq_dep_head(struct sfq_sched_data *q, sfq_index val) |
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{ |
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if (val < SFQ_MAX_FLOWS) |
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return &q->slots[val].dep; |
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return &q->dep[val - SFQ_MAX_FLOWS]; |
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} |
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static unsigned int sfq_hash(const struct sfq_sched_data *q, |
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const struct sk_buff *skb) |
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{ |
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return skb_get_hash_perturb(skb, &q->perturbation) & (q->divisor - 1); |
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} |
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static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch, |
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int *qerr) |
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{ |
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struct sfq_sched_data *q = qdisc_priv(sch); |
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struct tcf_result res; |
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struct tcf_proto *fl; |
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int result; |
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if (TC_H_MAJ(skb->priority) == sch->handle && |
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TC_H_MIN(skb->priority) > 0 && |
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TC_H_MIN(skb->priority) <= q->divisor) |
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return TC_H_MIN(skb->priority); |
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fl = rcu_dereference_bh(q->filter_list); |
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if (!fl) |
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return sfq_hash(q, skb) + 1; |
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*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; |
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result = tcf_classify(skb, NULL, fl, &res, false); |
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if (result >= 0) { |
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#ifdef CONFIG_NET_CLS_ACT |
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switch (result) { |
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case TC_ACT_STOLEN: |
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case TC_ACT_QUEUED: |
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case TC_ACT_TRAP: |
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*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; |
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fallthrough; |
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case TC_ACT_SHOT: |
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return 0; |
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} |
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#endif |
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if (TC_H_MIN(res.classid) <= q->divisor) |
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return TC_H_MIN(res.classid); |
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} |
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return 0; |
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} |
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/* |
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* x : slot number [0 .. SFQ_MAX_FLOWS - 1] |
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*/ |
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static inline void sfq_link(struct sfq_sched_data *q, sfq_index x) |
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{ |
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sfq_index p, n; |
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struct sfq_slot *slot = &q->slots[x]; |
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int qlen = slot->qlen; |
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p = qlen + SFQ_MAX_FLOWS; |
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n = q->dep[qlen].next; |
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slot->dep.next = n; |
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slot->dep.prev = p; |
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q->dep[qlen].next = x; /* sfq_dep_head(q, p)->next = x */ |
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sfq_dep_head(q, n)->prev = x; |
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} |
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#define sfq_unlink(q, x, n, p) \ |
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do { \ |
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n = q->slots[x].dep.next; \ |
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p = q->slots[x].dep.prev; \ |
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sfq_dep_head(q, p)->next = n; \ |
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sfq_dep_head(q, n)->prev = p; \ |
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} while (0) |
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static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x) |
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{ |
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sfq_index p, n; |
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int d; |
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sfq_unlink(q, x, n, p); |
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d = q->slots[x].qlen--; |
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if (n == p && q->cur_depth == d) |
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q->cur_depth--; |
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sfq_link(q, x); |
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} |
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static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x) |
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{ |
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sfq_index p, n; |
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int d; |
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sfq_unlink(q, x, n, p); |
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d = ++q->slots[x].qlen; |
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if (q->cur_depth < d) |
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q->cur_depth = d; |
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sfq_link(q, x); |
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} |
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/* helper functions : might be changed when/if skb use a standard list_head */ |
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|
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/* remove one skb from tail of slot queue */ |
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static inline struct sk_buff *slot_dequeue_tail(struct sfq_slot *slot) |
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{ |
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struct sk_buff *skb = slot->skblist_prev; |
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slot->skblist_prev = skb->prev; |
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skb->prev->next = (struct sk_buff *)slot; |
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skb->next = skb->prev = NULL; |
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return skb; |
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} |
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/* remove one skb from head of slot queue */ |
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static inline struct sk_buff *slot_dequeue_head(struct sfq_slot *slot) |
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{ |
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struct sk_buff *skb = slot->skblist_next; |
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slot->skblist_next = skb->next; |
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skb->next->prev = (struct sk_buff *)slot; |
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skb->next = skb->prev = NULL; |
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return skb; |
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} |
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static inline void slot_queue_init(struct sfq_slot *slot) |
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{ |
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memset(slot, 0, sizeof(*slot)); |
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slot->skblist_prev = slot->skblist_next = (struct sk_buff *)slot; |
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} |
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/* add skb to slot queue (tail add) */ |
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static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb) |
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{ |
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skb->prev = slot->skblist_prev; |
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skb->next = (struct sk_buff *)slot; |
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slot->skblist_prev->next = skb; |
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slot->skblist_prev = skb; |
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} |
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static unsigned int sfq_drop(struct Qdisc *sch, struct sk_buff **to_free) |
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{ |
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struct sfq_sched_data *q = qdisc_priv(sch); |
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sfq_index x, d = q->cur_depth; |
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struct sk_buff *skb; |
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unsigned int len; |
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struct sfq_slot *slot; |
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|
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/* Queue is full! Find the longest slot and drop tail packet from it */ |
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if (d > 1) { |
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x = q->dep[d].next; |
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slot = &q->slots[x]; |
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drop: |
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skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot); |
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len = qdisc_pkt_len(skb); |
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slot->backlog -= len; |
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sfq_dec(q, x); |
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sch->q.qlen--; |
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qdisc_qstats_backlog_dec(sch, skb); |
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qdisc_drop(skb, sch, to_free); |
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return len; |
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} |
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if (d == 1) { |
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/* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */ |
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x = q->tail->next; |
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slot = &q->slots[x]; |
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q->tail->next = slot->next; |
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q->ht[slot->hash] = SFQ_EMPTY_SLOT; |
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goto drop; |
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} |
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return 0; |
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} |
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/* Is ECN parameter configured */ |
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static int sfq_prob_mark(const struct sfq_sched_data *q) |
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{ |
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return q->flags & TC_RED_ECN; |
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} |
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/* Should packets over max threshold just be marked */ |
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static int sfq_hard_mark(const struct sfq_sched_data *q) |
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{ |
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return (q->flags & (TC_RED_ECN | TC_RED_HARDDROP)) == TC_RED_ECN; |
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} |
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static int sfq_headdrop(const struct sfq_sched_data *q) |
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{ |
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return q->headdrop; |
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} |
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static int |
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sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) |
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{ |
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struct sfq_sched_data *q = qdisc_priv(sch); |
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unsigned int hash, dropped; |
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sfq_index x, qlen; |
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struct sfq_slot *slot; |
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int ret; |
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struct sk_buff *head; |
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int delta; |
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hash = sfq_classify(skb, sch, &ret); |
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if (hash == 0) { |
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if (ret & __NET_XMIT_BYPASS) |
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qdisc_qstats_drop(sch); |
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__qdisc_drop(skb, to_free); |
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return ret; |
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} |
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hash--; |
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x = q->ht[hash]; |
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slot = &q->slots[x]; |
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if (x == SFQ_EMPTY_SLOT) { |
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x = q->dep[0].next; /* get a free slot */ |
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if (x >= SFQ_MAX_FLOWS) |
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return qdisc_drop(skb, sch, to_free); |
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q->ht[hash] = x; |
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slot = &q->slots[x]; |
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slot->hash = hash; |
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slot->backlog = 0; /* should already be 0 anyway... */ |
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red_set_vars(&slot->vars); |
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goto enqueue; |
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} |
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if (q->red_parms) { |
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slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms, |
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&slot->vars, |
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slot->backlog); |
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switch (red_action(q->red_parms, |
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&slot->vars, |
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slot->vars.qavg)) { |
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case RED_DONT_MARK: |
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break; |
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|
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case RED_PROB_MARK: |
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qdisc_qstats_overlimit(sch); |
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if (sfq_prob_mark(q)) { |
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/* We know we have at least one packet in queue */ |
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if (sfq_headdrop(q) && |
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INET_ECN_set_ce(slot->skblist_next)) { |
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q->stats.prob_mark_head++; |
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break; |
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} |
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if (INET_ECN_set_ce(skb)) { |
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q->stats.prob_mark++; |
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break; |
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} |
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} |
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q->stats.prob_drop++; |
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goto congestion_drop; |
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|
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case RED_HARD_MARK: |
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qdisc_qstats_overlimit(sch); |
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if (sfq_hard_mark(q)) { |
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/* We know we have at least one packet in queue */ |
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if (sfq_headdrop(q) && |
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INET_ECN_set_ce(slot->skblist_next)) { |
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q->stats.forced_mark_head++; |
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break; |
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} |
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if (INET_ECN_set_ce(skb)) { |
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q->stats.forced_mark++; |
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break; |
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} |
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} |
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q->stats.forced_drop++; |
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goto congestion_drop; |
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} |
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} |
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if (slot->qlen >= q->maxdepth) { |
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congestion_drop: |
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if (!sfq_headdrop(q)) |
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return qdisc_drop(skb, sch, to_free); |
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|
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/* We know we have at least one packet in queue */ |
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head = slot_dequeue_head(slot); |
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delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb); |
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sch->qstats.backlog -= delta; |
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slot->backlog -= delta; |
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qdisc_drop(head, sch, to_free); |
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|
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slot_queue_add(slot, skb); |
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qdisc_tree_reduce_backlog(sch, 0, delta); |
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return NET_XMIT_CN; |
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} |
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enqueue: |
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qdisc_qstats_backlog_inc(sch, skb); |
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slot->backlog += qdisc_pkt_len(skb); |
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slot_queue_add(slot, skb); |
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sfq_inc(q, x); |
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if (slot->qlen == 1) { /* The flow is new */ |
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if (q->tail == NULL) { /* It is the first flow */ |
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slot->next = x; |
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} else { |
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slot->next = q->tail->next; |
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q->tail->next = x; |
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} |
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/* We put this flow at the end of our flow list. |
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* This might sound unfair for a new flow to wait after old ones, |
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* but we could endup servicing new flows only, and freeze old ones. |
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*/ |
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q->tail = slot; |
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/* We could use a bigger initial quantum for new flows */ |
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slot->allot = q->scaled_quantum; |
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} |
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if (++sch->q.qlen <= q->limit) |
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return NET_XMIT_SUCCESS; |
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|
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qlen = slot->qlen; |
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dropped = sfq_drop(sch, to_free); |
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/* Return Congestion Notification only if we dropped a packet |
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* from this flow. |
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*/ |
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if (qlen != slot->qlen) { |
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qdisc_tree_reduce_backlog(sch, 0, dropped - qdisc_pkt_len(skb)); |
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return NET_XMIT_CN; |
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} |
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|
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/* As we dropped a packet, better let upper stack know this */ |
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qdisc_tree_reduce_backlog(sch, 1, dropped); |
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return NET_XMIT_SUCCESS; |
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} |
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|
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static struct sk_buff * |
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sfq_dequeue(struct Qdisc *sch) |
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{ |
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struct sfq_sched_data *q = qdisc_priv(sch); |
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struct sk_buff *skb; |
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sfq_index a, next_a; |
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struct sfq_slot *slot; |
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|
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/* No active slots */ |
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if (q->tail == NULL) |
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return NULL; |
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next_slot: |
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a = q->tail->next; |
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slot = &q->slots[a]; |
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if (slot->allot <= 0) { |
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q->tail = slot; |
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slot->allot += q->scaled_quantum; |
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goto next_slot; |
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} |
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skb = slot_dequeue_head(slot); |
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sfq_dec(q, a); |
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qdisc_bstats_update(sch, skb); |
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sch->q.qlen--; |
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qdisc_qstats_backlog_dec(sch, skb); |
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slot->backlog -= qdisc_pkt_len(skb); |
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/* Is the slot empty? */ |
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if (slot->qlen == 0) { |
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q->ht[slot->hash] = SFQ_EMPTY_SLOT; |
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next_a = slot->next; |
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if (a == next_a) { |
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q->tail = NULL; /* no more active slots */ |
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return skb; |
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} |
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q->tail->next = next_a; |
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} else { |
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slot->allot -= SFQ_ALLOT_SIZE(qdisc_pkt_len(skb)); |
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} |
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return skb; |
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} |
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|
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static void |
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sfq_reset(struct Qdisc *sch) |
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{ |
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struct sk_buff *skb; |
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|
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while ((skb = sfq_dequeue(sch)) != NULL) |
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rtnl_kfree_skbs(skb, skb); |
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} |
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|
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/* |
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* When q->perturbation is changed, we rehash all queued skbs |
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* to avoid OOO (Out Of Order) effects. |
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* We dont use sfq_dequeue()/sfq_enqueue() because we dont want to change |
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* counters. |
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*/ |
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static void sfq_rehash(struct Qdisc *sch) |
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{ |
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struct sfq_sched_data *q = qdisc_priv(sch); |
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struct sk_buff *skb; |
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int i; |
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struct sfq_slot *slot; |
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struct sk_buff_head list; |
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int dropped = 0; |
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unsigned int drop_len = 0; |
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|
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__skb_queue_head_init(&list); |
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|
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for (i = 0; i < q->maxflows; i++) { |
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slot = &q->slots[i]; |
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if (!slot->qlen) |
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continue; |
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while (slot->qlen) { |
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skb = slot_dequeue_head(slot); |
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sfq_dec(q, i); |
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__skb_queue_tail(&list, skb); |
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} |
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slot->backlog = 0; |
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red_set_vars(&slot->vars); |
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q->ht[slot->hash] = SFQ_EMPTY_SLOT; |
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} |
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q->tail = NULL; |
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|
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while ((skb = __skb_dequeue(&list)) != NULL) { |
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unsigned int hash = sfq_hash(q, skb); |
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sfq_index x = q->ht[hash]; |
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|
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slot = &q->slots[x]; |
|
if (x == SFQ_EMPTY_SLOT) { |
|
x = q->dep[0].next; /* get a free slot */ |
|
if (x >= SFQ_MAX_FLOWS) { |
|
drop: |
|
qdisc_qstats_backlog_dec(sch, skb); |
|
drop_len += qdisc_pkt_len(skb); |
|
kfree_skb(skb); |
|
dropped++; |
|
continue; |
|
} |
|
q->ht[hash] = x; |
|
slot = &q->slots[x]; |
|
slot->hash = hash; |
|
} |
|
if (slot->qlen >= q->maxdepth) |
|
goto drop; |
|
slot_queue_add(slot, skb); |
|
if (q->red_parms) |
|
slot->vars.qavg = red_calc_qavg(q->red_parms, |
|
&slot->vars, |
|
slot->backlog); |
|
slot->backlog += qdisc_pkt_len(skb); |
|
sfq_inc(q, x); |
|
if (slot->qlen == 1) { /* The flow is new */ |
|
if (q->tail == NULL) { /* It is the first flow */ |
|
slot->next = x; |
|
} else { |
|
slot->next = q->tail->next; |
|
q->tail->next = x; |
|
} |
|
q->tail = slot; |
|
slot->allot = q->scaled_quantum; |
|
} |
|
} |
|
sch->q.qlen -= dropped; |
|
qdisc_tree_reduce_backlog(sch, dropped, drop_len); |
|
} |
|
|
|
static void sfq_perturbation(struct timer_list *t) |
|
{ |
|
struct sfq_sched_data *q = from_timer(q, t, perturb_timer); |
|
struct Qdisc *sch = q->sch; |
|
spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch)); |
|
siphash_key_t nkey; |
|
|
|
get_random_bytes(&nkey, sizeof(nkey)); |
|
spin_lock(root_lock); |
|
q->perturbation = nkey; |
|
if (!q->filter_list && q->tail) |
|
sfq_rehash(sch); |
|
spin_unlock(root_lock); |
|
|
|
if (q->perturb_period) |
|
mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
|
} |
|
|
|
static int sfq_change(struct Qdisc *sch, struct nlattr *opt) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
struct tc_sfq_qopt *ctl = nla_data(opt); |
|
struct tc_sfq_qopt_v1 *ctl_v1 = NULL; |
|
unsigned int qlen, dropped = 0; |
|
struct red_parms *p = NULL; |
|
struct sk_buff *to_free = NULL; |
|
struct sk_buff *tail = NULL; |
|
|
|
if (opt->nla_len < nla_attr_size(sizeof(*ctl))) |
|
return -EINVAL; |
|
if (opt->nla_len >= nla_attr_size(sizeof(*ctl_v1))) |
|
ctl_v1 = nla_data(opt); |
|
if (ctl->divisor && |
|
(!is_power_of_2(ctl->divisor) || ctl->divisor > 65536)) |
|
return -EINVAL; |
|
|
|
/* slot->allot is a short, make sure quantum is not too big. */ |
|
if (ctl->quantum) { |
|
unsigned int scaled = SFQ_ALLOT_SIZE(ctl->quantum); |
|
|
|
if (scaled <= 0 || scaled > SHRT_MAX) |
|
return -EINVAL; |
|
} |
|
|
|
if (ctl_v1 && !red_check_params(ctl_v1->qth_min, ctl_v1->qth_max, |
|
ctl_v1->Wlog, ctl_v1->Scell_log, NULL)) |
|
return -EINVAL; |
|
if (ctl_v1 && ctl_v1->qth_min) { |
|
p = kmalloc(sizeof(*p), GFP_KERNEL); |
|
if (!p) |
|
return -ENOMEM; |
|
} |
|
sch_tree_lock(sch); |
|
if (ctl->quantum) { |
|
q->quantum = ctl->quantum; |
|
q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum); |
|
} |
|
q->perturb_period = ctl->perturb_period * HZ; |
|
if (ctl->flows) |
|
q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); |
|
if (ctl->divisor) { |
|
q->divisor = ctl->divisor; |
|
q->maxflows = min_t(u32, q->maxflows, q->divisor); |
|
} |
|
if (ctl_v1) { |
|
if (ctl_v1->depth) |
|
q->maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH); |
|
if (p) { |
|
swap(q->red_parms, p); |
|
red_set_parms(q->red_parms, |
|
ctl_v1->qth_min, ctl_v1->qth_max, |
|
ctl_v1->Wlog, |
|
ctl_v1->Plog, ctl_v1->Scell_log, |
|
NULL, |
|
ctl_v1->max_P); |
|
} |
|
q->flags = ctl_v1->flags; |
|
q->headdrop = ctl_v1->headdrop; |
|
} |
|
if (ctl->limit) { |
|
q->limit = min_t(u32, ctl->limit, q->maxdepth * q->maxflows); |
|
q->maxflows = min_t(u32, q->maxflows, q->limit); |
|
} |
|
|
|
qlen = sch->q.qlen; |
|
while (sch->q.qlen > q->limit) { |
|
dropped += sfq_drop(sch, &to_free); |
|
if (!tail) |
|
tail = to_free; |
|
} |
|
|
|
rtnl_kfree_skbs(to_free, tail); |
|
qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped); |
|
|
|
del_timer(&q->perturb_timer); |
|
if (q->perturb_period) { |
|
mod_timer(&q->perturb_timer, jiffies + q->perturb_period); |
|
get_random_bytes(&q->perturbation, sizeof(q->perturbation)); |
|
} |
|
sch_tree_unlock(sch); |
|
kfree(p); |
|
return 0; |
|
} |
|
|
|
static void *sfq_alloc(size_t sz) |
|
{ |
|
return kvmalloc(sz, GFP_KERNEL); |
|
} |
|
|
|
static void sfq_free(void *addr) |
|
{ |
|
kvfree(addr); |
|
} |
|
|
|
static void sfq_destroy(struct Qdisc *sch) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
|
|
tcf_block_put(q->block); |
|
q->perturb_period = 0; |
|
del_timer_sync(&q->perturb_timer); |
|
sfq_free(q->ht); |
|
sfq_free(q->slots); |
|
kfree(q->red_parms); |
|
} |
|
|
|
static int sfq_init(struct Qdisc *sch, struct nlattr *opt, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
int i; |
|
int err; |
|
|
|
q->sch = sch; |
|
timer_setup(&q->perturb_timer, sfq_perturbation, TIMER_DEFERRABLE); |
|
|
|
err = tcf_block_get(&q->block, &q->filter_list, sch, extack); |
|
if (err) |
|
return err; |
|
|
|
for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) { |
|
q->dep[i].next = i + SFQ_MAX_FLOWS; |
|
q->dep[i].prev = i + SFQ_MAX_FLOWS; |
|
} |
|
|
|
q->limit = SFQ_MAX_DEPTH; |
|
q->maxdepth = SFQ_MAX_DEPTH; |
|
q->cur_depth = 0; |
|
q->tail = NULL; |
|
q->divisor = SFQ_DEFAULT_HASH_DIVISOR; |
|
q->maxflows = SFQ_DEFAULT_FLOWS; |
|
q->quantum = psched_mtu(qdisc_dev(sch)); |
|
q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum); |
|
q->perturb_period = 0; |
|
get_random_bytes(&q->perturbation, sizeof(q->perturbation)); |
|
|
|
if (opt) { |
|
int err = sfq_change(sch, opt); |
|
if (err) |
|
return err; |
|
} |
|
|
|
q->ht = sfq_alloc(sizeof(q->ht[0]) * q->divisor); |
|
q->slots = sfq_alloc(sizeof(q->slots[0]) * q->maxflows); |
|
if (!q->ht || !q->slots) { |
|
/* Note: sfq_destroy() will be called by our caller */ |
|
return -ENOMEM; |
|
} |
|
|
|
for (i = 0; i < q->divisor; i++) |
|
q->ht[i] = SFQ_EMPTY_SLOT; |
|
|
|
for (i = 0; i < q->maxflows; i++) { |
|
slot_queue_init(&q->slots[i]); |
|
sfq_link(q, i); |
|
} |
|
if (q->limit >= 1) |
|
sch->flags |= TCQ_F_CAN_BYPASS; |
|
else |
|
sch->flags &= ~TCQ_F_CAN_BYPASS; |
|
return 0; |
|
} |
|
|
|
static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
unsigned char *b = skb_tail_pointer(skb); |
|
struct tc_sfq_qopt_v1 opt; |
|
struct red_parms *p = q->red_parms; |
|
|
|
memset(&opt, 0, sizeof(opt)); |
|
opt.v0.quantum = q->quantum; |
|
opt.v0.perturb_period = q->perturb_period / HZ; |
|
opt.v0.limit = q->limit; |
|
opt.v0.divisor = q->divisor; |
|
opt.v0.flows = q->maxflows; |
|
opt.depth = q->maxdepth; |
|
opt.headdrop = q->headdrop; |
|
|
|
if (p) { |
|
opt.qth_min = p->qth_min >> p->Wlog; |
|
opt.qth_max = p->qth_max >> p->Wlog; |
|
opt.Wlog = p->Wlog; |
|
opt.Plog = p->Plog; |
|
opt.Scell_log = p->Scell_log; |
|
opt.max_P = p->max_P; |
|
} |
|
memcpy(&opt.stats, &q->stats, sizeof(opt.stats)); |
|
opt.flags = q->flags; |
|
|
|
if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt)) |
|
goto nla_put_failure; |
|
|
|
return skb->len; |
|
|
|
nla_put_failure: |
|
nlmsg_trim(skb, b); |
|
return -1; |
|
} |
|
|
|
static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg) |
|
{ |
|
return NULL; |
|
} |
|
|
|
static unsigned long sfq_find(struct Qdisc *sch, u32 classid) |
|
{ |
|
return 0; |
|
} |
|
|
|
static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent, |
|
u32 classid) |
|
{ |
|
return 0; |
|
} |
|
|
|
static void sfq_unbind(struct Qdisc *q, unsigned long cl) |
|
{ |
|
} |
|
|
|
static struct tcf_block *sfq_tcf_block(struct Qdisc *sch, unsigned long cl, |
|
struct netlink_ext_ack *extack) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
|
|
if (cl) |
|
return NULL; |
|
return q->block; |
|
} |
|
|
|
static int sfq_dump_class(struct Qdisc *sch, unsigned long cl, |
|
struct sk_buff *skb, struct tcmsg *tcm) |
|
{ |
|
tcm->tcm_handle |= TC_H_MIN(cl); |
|
return 0; |
|
} |
|
|
|
static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl, |
|
struct gnet_dump *d) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
sfq_index idx = q->ht[cl - 1]; |
|
struct gnet_stats_queue qs = { 0 }; |
|
struct tc_sfq_xstats xstats = { 0 }; |
|
|
|
if (idx != SFQ_EMPTY_SLOT) { |
|
const struct sfq_slot *slot = &q->slots[idx]; |
|
|
|
xstats.allot = slot->allot << SFQ_ALLOT_SHIFT; |
|
qs.qlen = slot->qlen; |
|
qs.backlog = slot->backlog; |
|
} |
|
if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) |
|
return -1; |
|
return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); |
|
} |
|
|
|
static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg) |
|
{ |
|
struct sfq_sched_data *q = qdisc_priv(sch); |
|
unsigned int i; |
|
|
|
if (arg->stop) |
|
return; |
|
|
|
for (i = 0; i < q->divisor; i++) { |
|
if (q->ht[i] == SFQ_EMPTY_SLOT || |
|
arg->count < arg->skip) { |
|
arg->count++; |
|
continue; |
|
} |
|
if (arg->fn(sch, i + 1, arg) < 0) { |
|
arg->stop = 1; |
|
break; |
|
} |
|
arg->count++; |
|
} |
|
} |
|
|
|
static const struct Qdisc_class_ops sfq_class_ops = { |
|
.leaf = sfq_leaf, |
|
.find = sfq_find, |
|
.tcf_block = sfq_tcf_block, |
|
.bind_tcf = sfq_bind, |
|
.unbind_tcf = sfq_unbind, |
|
.dump = sfq_dump_class, |
|
.dump_stats = sfq_dump_class_stats, |
|
.walk = sfq_walk, |
|
}; |
|
|
|
static struct Qdisc_ops sfq_qdisc_ops __read_mostly = { |
|
.cl_ops = &sfq_class_ops, |
|
.id = "sfq", |
|
.priv_size = sizeof(struct sfq_sched_data), |
|
.enqueue = sfq_enqueue, |
|
.dequeue = sfq_dequeue, |
|
.peek = qdisc_peek_dequeued, |
|
.init = sfq_init, |
|
.reset = sfq_reset, |
|
.destroy = sfq_destroy, |
|
.change = NULL, |
|
.dump = sfq_dump, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
static int __init sfq_module_init(void) |
|
{ |
|
return register_qdisc(&sfq_qdisc_ops); |
|
} |
|
static void __exit sfq_module_exit(void) |
|
{ |
|
unregister_qdisc(&sfq_qdisc_ops); |
|
} |
|
module_init(sfq_module_init) |
|
module_exit(sfq_module_exit) |
|
MODULE_LICENSE("GPL");
|
|
|