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-rw-r--r--net/sched/sch_sfq.c369
1 files changed, 236 insertions, 133 deletions
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 4f5510e2bd6..0a7964009e8 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -17,14 +17,13 @@
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/init.h>
-#include <linux/ipv6.h>
#include <linux/skbuff.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
-#include <net/ip.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
+#include <net/flow_keys.h>
/* Stochastic Fairness Queuing algorithm.
@@ -67,16 +66,18 @@
SFQ is superior for this purpose.
IMPLEMENTATION:
- This implementation limits maximal queue length to 128;
- max mtu to 2^18-1; max 128 flows, number of hash buckets to 1024.
- The only goal of this restrictions was that all data
- fit into one 4K page on 32bit arches.
+ This implementation limits :
+ - maximal queue length per flow to 127 packets.
+ - max mtu to 2^18-1;
+ - max 65408 flows,
+ - number of hash buckets to 65536.
It is easy to increase these values, but not in flight. */
-#define SFQ_DEPTH 128 /* max number of packets per flow */
-#define SFQ_SLOTS 128 /* max number of flows */
-#define SFQ_EMPTY_SLOT 255
+#define SFQ_MAX_DEPTH 127 /* max number of packets per flow */
+#define SFQ_DEFAULT_FLOWS 128
+#define SFQ_MAX_FLOWS (0x10000 - SFQ_MAX_DEPTH - 1) /* max number of flows */
+#define SFQ_EMPTY_SLOT 0xffff
#define SFQ_DEFAULT_HASH_DIVISOR 1024
/* We use 16 bits to store allot, and want to handle packets up to 64K
@@ -85,13 +86,13 @@
#define SFQ_ALLOT_SHIFT 3
#define SFQ_ALLOT_SIZE(X) DIV_ROUND_UP(X, 1 << SFQ_ALLOT_SHIFT)
-/* This type should contain at least SFQ_DEPTH + SFQ_SLOTS values */
-typedef unsigned char sfq_index;
+/* This type should contain at least SFQ_MAX_DEPTH + 1 + SFQ_MAX_FLOWS values */
+typedef u16 sfq_index;
/*
* We dont use pointers to save space.
- * Small indexes [0 ... SFQ_SLOTS - 1] are 'pointers' to slots[] array
- * while following values [SFQ_SLOTS ... SFQ_SLOTS + SFQ_DEPTH - 1]
+ * Small indexes [0 ... SFQ_MAX_FLOWS - 1] are 'pointers' to slots[] array
+ * while following values [SFQ_MAX_FLOWS ... SFQ_MAX_FLOWS + SFQ_MAX_DEPTH]
* are 'pointers' to dep[] array
*/
struct sfq_head {
@@ -103,28 +104,38 @@ struct sfq_slot {
struct sk_buff *skblist_next;
struct sk_buff *skblist_prev;
sfq_index qlen; /* number of skbs in skblist */
- sfq_index next; /* next slot in sfq chain */
+ sfq_index next; /* next slot in sfq RR chain */
struct sfq_head dep; /* anchor in dep[] chains */
unsigned short hash; /* hash value (index in ht[]) */
short allot; /* credit for this slot */
};
struct sfq_sched_data {
-/* Parameters */
- int perturb_period;
- unsigned int quantum; /* Allotment per round: MUST BE >= MTU */
- int limit;
+/* frequently used fields */
+ int limit; /* limit of total number of packets in this qdisc */
unsigned int divisor; /* number of slots in hash table */
-/* Variables */
- struct tcf_proto *filter_list;
- struct timer_list perturb_timer;
+ unsigned int maxflows; /* number of flows in flows array */
+ int headdrop;
+ int maxdepth; /* limit of packets per flow */
+
u32 perturbation;
+ struct tcf_proto *filter_list;
sfq_index cur_depth; /* depth of longest slot */
unsigned short scaled_quantum; /* SFQ_ALLOT_SIZE(quantum) */
struct sfq_slot *tail; /* current slot in round */
- sfq_index *ht; /* Hash table (divisor slots) */
- struct sfq_slot slots[SFQ_SLOTS];
- struct sfq_head dep[SFQ_DEPTH]; /* Linked list of slots, indexed by depth */
+ sfq_index *ht; /* Hash table ('divisor' slots) */
+ struct sfq_slot *slots; /* Flows table ('maxflows' entries) */
+
+ struct sfq_head dep[SFQ_MAX_DEPTH + 1];
+ /* Linked lists of slots, indexed by depth
+ * dep[0] : list of unused flows
+ * dep[1] : list of flows with 1 packet
+ * dep[X] : list of flows with X packets
+ */
+
+ int perturb_period;
+ unsigned int quantum; /* Allotment per round: MUST BE >= MTU */
+ struct timer_list perturb_timer;
};
/*
@@ -132,66 +143,36 @@ struct sfq_sched_data {
*/
static inline struct sfq_head *sfq_dep_head(struct sfq_sched_data *q, sfq_index val)
{
- if (val < SFQ_SLOTS)
+ if (val < SFQ_MAX_FLOWS)
return &q->slots[val].dep;
- return &q->dep[val - SFQ_SLOTS];
+ return &q->dep[val - SFQ_MAX_FLOWS];
}
-static unsigned int sfq_fold_hash(struct sfq_sched_data *q, u32 h, u32 h1)
+/*
+ * In order to be able to quickly rehash our queue when timer changes
+ * q->perturbation, we store flow_keys in skb->cb[]
+ */
+struct sfq_skb_cb {
+ struct flow_keys keys;
+};
+
+static inline struct sfq_skb_cb *sfq_skb_cb(const struct sk_buff *skb)
{
- return jhash_2words(h, h1, q->perturbation) & (q->divisor - 1);
+ BUILD_BUG_ON(sizeof(skb->cb) <
+ sizeof(struct qdisc_skb_cb) + sizeof(struct sfq_skb_cb));
+ return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data;
}
-static unsigned int sfq_hash(struct sfq_sched_data *q, struct sk_buff *skb)
+static unsigned int sfq_hash(const struct sfq_sched_data *q,
+ const struct sk_buff *skb)
{
- u32 h, h2;
-
- switch (skb->protocol) {
- case htons(ETH_P_IP):
- {
- const struct iphdr *iph;
- int poff;
-
- if (!pskb_network_may_pull(skb, sizeof(*iph)))
- goto err;
- iph = ip_hdr(skb);
- h = (__force u32)iph->daddr;
- h2 = (__force u32)iph->saddr ^ iph->protocol;
- if (ip_is_fragment(iph))
- break;
- poff = proto_ports_offset(iph->protocol);
- if (poff >= 0 &&
- pskb_network_may_pull(skb, iph->ihl * 4 + 4 + poff)) {
- iph = ip_hdr(skb);
- h2 ^= *(u32 *)((void *)iph + iph->ihl * 4 + poff);
- }
- break;
- }
- case htons(ETH_P_IPV6):
- {
- const struct ipv6hdr *iph;
- int poff;
-
- if (!pskb_network_may_pull(skb, sizeof(*iph)))
- goto err;
- iph = ipv6_hdr(skb);
- h = (__force u32)iph->daddr.s6_addr32[3];
- h2 = (__force u32)iph->saddr.s6_addr32[3] ^ iph->nexthdr;
- poff = proto_ports_offset(iph->nexthdr);
- if (poff >= 0 &&
- pskb_network_may_pull(skb, sizeof(*iph) + 4 + poff)) {
- iph = ipv6_hdr(skb);
- h2 ^= *(u32 *)((void *)iph + sizeof(*iph) + poff);
- }
- break;
- }
- default:
-err:
- h = (unsigned long)skb_dst(skb) ^ (__force u32)skb->protocol;
- h2 = (unsigned long)skb->sk;
- }
+ const struct flow_keys *keys = &sfq_skb_cb(skb)->keys;
+ unsigned int hash;
- return sfq_fold_hash(q, h, h2);
+ hash = jhash_3words((__force u32)keys->dst,
+ (__force u32)keys->src ^ keys->ip_proto,
+ (__force u32)keys->ports, q->perturbation);
+ return hash & (q->divisor - 1);
}
static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
@@ -206,8 +187,10 @@ static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
TC_H_MIN(skb->priority) <= q->divisor)
return TC_H_MIN(skb->priority);
- if (!q->filter_list)
+ if (!q->filter_list) {
+ skb_flow_dissect(skb, &sfq_skb_cb(skb)->keys);
return sfq_hash(q, skb) + 1;
+ }
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
result = tc_classify(skb, q->filter_list, &res);
@@ -228,18 +211,19 @@ static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
}
/*
- * x : slot number [0 .. SFQ_SLOTS - 1]
+ * x : slot number [0 .. SFQ_MAX_FLOWS - 1]
*/
static inline void sfq_link(struct sfq_sched_data *q, sfq_index x)
{
sfq_index p, n;
- int qlen = q->slots[x].qlen;
+ struct sfq_slot *slot = &q->slots[x];
+ int qlen = slot->qlen;
- p = qlen + SFQ_SLOTS;
+ p = qlen + SFQ_MAX_FLOWS;
n = q->dep[qlen].next;
- q->slots[x].dep.next = n;
- q->slots[x].dep.prev = p;
+ slot->dep.next = n;
+ slot->dep.prev = p;
q->dep[qlen].next = x; /* sfq_dep_head(q, p)->next = x */
sfq_dep_head(q, n)->prev = x;
@@ -304,6 +288,7 @@ static inline struct sk_buff *slot_dequeue_head(struct sfq_slot *slot)
static inline void slot_queue_init(struct sfq_slot *slot)
{
+ memset(slot, 0, sizeof(*slot));
slot->skblist_prev = slot->skblist_next = (struct sk_buff *)slot;
}
@@ -334,7 +319,7 @@ static unsigned int sfq_drop(struct Qdisc *sch)
x = q->dep[d].next;
slot = &q->slots[x];
drop:
- skb = slot_dequeue_tail(slot);
+ skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot);
len = qdisc_pkt_len(skb);
sfq_dec(q, x);
kfree_skb(skb);
@@ -378,16 +363,27 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
slot = &q->slots[x];
if (x == SFQ_EMPTY_SLOT) {
x = q->dep[0].next; /* get a free slot */
+ if (x >= SFQ_MAX_FLOWS)
+ return qdisc_drop(skb, sch);
q->ht[hash] = x;
slot = &q->slots[x];
slot->hash = hash;
}
- /* If selected queue has length q->limit, do simple tail drop,
- * i.e. drop _this_ packet.
- */
- if (slot->qlen >= q->limit)
- return qdisc_drop(skb, sch);
+ if (slot->qlen >= q->maxdepth) {
+ struct sk_buff *head;
+
+ if (!q->headdrop)
+ return qdisc_drop(skb, sch);
+
+ head = slot_dequeue_head(slot);
+ sch->qstats.backlog -= qdisc_pkt_len(head);
+ qdisc_drop(head, sch);
+
+ sch->qstats.backlog += qdisc_pkt_len(skb);
+ slot_queue_add(slot, skb);
+ return NET_XMIT_CN;
+ }
sch->qstats.backlog += qdisc_pkt_len(skb);
slot_queue_add(slot, skb);
@@ -395,11 +391,11 @@ sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
if (slot->qlen == 1) { /* The flow is new */
if (q->tail == NULL) { /* It is the first flow */
slot->next = x;
+ q->tail = slot;
} else {
slot->next = q->tail->next;
q->tail->next = x;
}
- q->tail = slot;
slot->allot = q->scaled_quantum;
}
if (++sch->q.qlen <= q->limit)
@@ -468,12 +464,83 @@ sfq_reset(struct Qdisc *sch)
kfree_skb(skb);
}
+/*
+ * When q->perturbation is changed, we rehash all queued skbs
+ * to avoid OOO (Out Of Order) effects.
+ * We dont use sfq_dequeue()/sfq_enqueue() because we dont want to change
+ * counters.
+ */
+static void sfq_rehash(struct Qdisc *sch)
+{
+ struct sfq_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+ int i;
+ struct sfq_slot *slot;
+ struct sk_buff_head list;
+ int dropped = 0;
+
+ __skb_queue_head_init(&list);
+
+ for (i = 0; i < q->maxflows; i++) {
+ slot = &q->slots[i];
+ if (!slot->qlen)
+ continue;
+ while (slot->qlen) {
+ skb = slot_dequeue_head(slot);
+ sfq_dec(q, i);
+ __skb_queue_tail(&list, skb);
+ }
+ q->ht[slot->hash] = SFQ_EMPTY_SLOT;
+ }
+ q->tail = NULL;
+
+ while ((skb = __skb_dequeue(&list)) != NULL) {
+ unsigned int hash = sfq_hash(q, skb);
+ sfq_index x = q->ht[hash];
+
+ slot = &q->slots[x];
+ if (x == SFQ_EMPTY_SLOT) {
+ x = q->dep[0].next; /* get a free slot */
+ if (x >= SFQ_MAX_FLOWS) {
+drop: sch->qstats.backlog -= 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);
+ 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_decrease_qlen(sch, dropped);
+}
+
static void sfq_perturbation(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
struct sfq_sched_data *q = qdisc_priv(sch);
+ spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
+ spin_lock(root_lock);
q->perturbation = net_random();
+ 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);
@@ -483,23 +550,39 @@ 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;
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;
sch_tree_lock(sch);
- q->quantum = ctl->quantum ? : psched_mtu(qdisc_dev(sch));
- q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
+ if (ctl->quantum) {
+ q->quantum = ctl->quantum;
+ q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
+ }
q->perturb_period = ctl->perturb_period * HZ;
- if (ctl->limit)
- q->limit = min_t(u32, ctl->limit, SFQ_DEPTH - 1);
- if (ctl->divisor)
+ 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);
+ 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)
sfq_drop(sch);
@@ -514,46 +597,77 @@ static int sfq_change(struct Qdisc *sch, struct nlattr *opt)
return 0;
}
+static void *sfq_alloc(size_t sz)
+{
+ void *ptr = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN);
+
+ if (!ptr)
+ ptr = vmalloc(sz);
+ return ptr;
+}
+
+static void sfq_free(void *addr)
+{
+ if (addr) {
+ if (is_vmalloc_addr(addr))
+ vfree(addr);
+ else
+ kfree(addr);
+ }
+}
+
+static void sfq_destroy(struct Qdisc *sch)
+{
+ struct sfq_sched_data *q = qdisc_priv(sch);
+
+ tcf_destroy_chain(&q->filter_list);
+ q->perturb_period = 0;
+ del_timer_sync(&q->perturb_timer);
+ sfq_free(q->ht);
+ sfq_free(q->slots);
+}
+
static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
{
struct sfq_sched_data *q = qdisc_priv(sch);
- size_t sz;
int i;
q->perturb_timer.function = sfq_perturbation;
q->perturb_timer.data = (unsigned long)sch;
init_timer_deferrable(&q->perturb_timer);
- for (i = 0; i < SFQ_DEPTH; i++) {
- q->dep[i].next = i + SFQ_SLOTS;
- q->dep[i].prev = i + SFQ_SLOTS;
+ 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_DEPTH - 1;
+ q->limit = SFQ_MAX_DEPTH;
+ q->maxdepth = SFQ_MAX_DEPTH;
q->cur_depth = 0;
q->tail = NULL;
q->divisor = SFQ_DEFAULT_HASH_DIVISOR;
- if (opt == NULL) {
- q->quantum = psched_mtu(qdisc_dev(sch));
- q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
- q->perturb_period = 0;
- q->perturbation = net_random();
- } else {
+ q->maxflows = SFQ_DEFAULT_FLOWS;
+ q->quantum = psched_mtu(qdisc_dev(sch));
+ q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
+ q->perturb_period = 0;
+ q->perturbation = net_random();
+
+ if (opt) {
int err = sfq_change(sch, opt);
if (err)
return err;
}
- sz = sizeof(q->ht[0]) * q->divisor;
- q->ht = kmalloc(sz, GFP_KERNEL);
- if (!q->ht && sz > PAGE_SIZE)
- q->ht = vmalloc(sz);
- if (!q->ht)
+ 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) {
+ sfq_destroy(sch);
return -ENOMEM;
+ }
for (i = 0; i < q->divisor; i++)
q->ht[i] = SFQ_EMPTY_SLOT;
- for (i = 0; i < SFQ_SLOTS; i++) {
+ for (i = 0; i < q->maxflows; i++) {
slot_queue_init(&q->slots[i]);
sfq_link(q, i);
}
@@ -564,31 +678,20 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
return 0;
}
-static void sfq_destroy(struct Qdisc *sch)
-{
- struct sfq_sched_data *q = qdisc_priv(sch);
-
- tcf_destroy_chain(&q->filter_list);
- q->perturb_period = 0;
- del_timer_sync(&q->perturb_timer);
- if (is_vmalloc_addr(q->ht))
- vfree(q->ht);
- else
- kfree(q->ht);
-}
-
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 opt;
-
- opt.quantum = q->quantum;
- opt.perturb_period = q->perturb_period / HZ;
-
- opt.limit = q->limit;
- opt.divisor = q->divisor;
- opt.flows = q->limit;
+ struct tc_sfq_qopt_v1 opt;
+
+ 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;
NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);