fq_codel: Fair Queue Codel AQM

Fair Queue Codel packet scheduler

Principles :

- Packets are classified (internal classifier or external) on flows.
- This is a Stochastic model (as we use a hash, several flows might
                              be hashed on same slot)
- Each flow has a CoDel managed queue.
- Flows are linked onto two (Round Robin) lists,
  so that new flows have priority on old ones.

- For a given flow, packets are not reordered (CoDel uses a FIFO)
- head drops only.
- ECN capability is on by default.
- Very low memory footprint (64 bytes per flow)

tc qdisc ... fq_codel [ limit PACKETS ] [ flows number ]
                      [ target TIME ] [ interval TIME ] [ noecn ]
                      [ quantum BYTES ]

defaults : 1024 flows, 10240 packets limit, quantum : device MTU
           target : 5ms (CoDel default)
           interval : 100ms (CoDel default)

Impressive results on load :

class htb 1:1 root leaf 10: prio 0 quantum 1514 rate 200000Kbit ceil 200000Kbit burst 1475b/8 mpu 0b overhead 0b cburst 1475b/8 mpu 0b overhead 0b level 0
 Sent 43304920109 bytes 33063109 pkt (dropped 0, overlimits 0 requeues 0)
 rate 201691Kbit 28595pps backlog 0b 312p requeues 0
 lended: 33063109 borrowed: 0 giants: 0
 tokens: -912 ctokens: -912

class fq_codel 10:1735 parent 10:
 (dropped 1292, overlimits 0 requeues 0)
 backlog 15140b 10p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.1ms
class fq_codel 10:4524 parent 10:
 (dropped 1291, overlimits 0 requeues 0)
 backlog 16654b 11p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.1ms
class fq_codel 10:4e74 parent 10:
 (dropped 1290, overlimits 0 requeues 0)
 backlog 6056b 4p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 6.4ms dropping drop_next 92.0ms
class fq_codel 10:628a parent 10:
 (dropped 1289, overlimits 0 requeues 0)
 backlog 7570b 5p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 5.4ms dropping drop_next 90.9ms
class fq_codel 10:a4b3 parent 10:
 (dropped 302, overlimits 0 requeues 0)
 backlog 16654b 11p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.1ms
class fq_codel 10:c3c2 parent 10:
 (dropped 1284, overlimits 0 requeues 0)
 backlog 13626b 9p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 5.9ms
class fq_codel 10:d331 parent 10:
 (dropped 299, overlimits 0 requeues 0)
 backlog 15140b 10p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.0ms
class fq_codel 10:d526 parent 10:
 (dropped 12160, overlimits 0 requeues 0)
 backlog 35870b 211p requeues 0
  deficit 1508 count 12160 lastcount 1 ldelay 15.3ms dropping drop_next 247us
class fq_codel 10:e2c6 parent 10:
 (dropped 1288, overlimits 0 requeues 0)
 backlog 15140b 10p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.1ms
class fq_codel 10:eab5 parent 10:
 (dropped 1285, overlimits 0 requeues 0)
 backlog 16654b 11p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 5.9ms
class fq_codel 10:f220 parent 10:
 (dropped 1289, overlimits 0 requeues 0)
 backlog 15140b 10p requeues 0
  deficit 1514 count 1 lastcount 1 ldelay 7.1ms

qdisc htb 1: root refcnt 6 r2q 10 default 1 direct_packets_stat 0 ver 3.17
 Sent 43331086547 bytes 33092812 pkt (dropped 0, overlimits 66063544 requeues 71)
 rate 201697Kbit 28602pps backlog 0b 260p requeues 71
qdisc fq_codel 10: parent 1:1 limit 10240p flows 65536 target 5.0ms interval 100.0ms ecn
 Sent 43331086547 bytes 33092812 pkt (dropped 949359, overlimits 0 requeues 0)
 rate 201697Kbit 28602pps backlog 189352b 260p requeues 0
  maxpacket 1514 drop_overlimit 0 new_flow_count 5582 ecn_mark 125593
  new_flows_len 0 old_flows_len 11

PING 172.30.42.18 (172.30.42.18) 56(84) bytes of data.
64 bytes from 172.30.42.18: icmp_req=1 ttl=64 time=0.227 ms
64 bytes from 172.30.42.18: icmp_req=2 ttl=64 time=0.165 ms
64 bytes from 172.30.42.18: icmp_req=3 ttl=64 time=0.166 ms
64 bytes from 172.30.42.18: icmp_req=4 ttl=64 time=0.151 ms
64 bytes from 172.30.42.18: icmp_req=5 ttl=64 time=0.164 ms
64 bytes from 172.30.42.18: icmp_req=6 ttl=64 time=0.172 ms
64 bytes from 172.30.42.18: icmp_req=7 ttl=64 time=0.175 ms
64 bytes from 172.30.42.18: icmp_req=8 ttl=64 time=0.183 ms
64 bytes from 172.30.42.18: icmp_req=9 ttl=64 time=0.158 ms
64 bytes from 172.30.42.18: icmp_req=10 ttl=64 time=0.200 ms

10 packets transmitted, 10 received, 0% packet loss, time 8999ms
rtt min/avg/max/mdev = 0.151/0.176/0.227/0.022 ms

Much better than SFQ because of priority given to new flows, and fast
path dirtying less cache lines.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-05-11 09:30:50 +00:00 коммит произвёл David S. Miller
Родитель 536edd6710
Коммит 4b549a2ef4
4 изменённых файлов: 690 добавлений и 0 удалений

Просмотреть файл

@ -681,4 +681,58 @@ struct tc_codel_xstats {
__u32 dropping; /* are we in dropping state ? */
};
/* FQ_CODEL */
enum {
TCA_FQ_CODEL_UNSPEC,
TCA_FQ_CODEL_TARGET,
TCA_FQ_CODEL_LIMIT,
TCA_FQ_CODEL_INTERVAL,
TCA_FQ_CODEL_ECN,
TCA_FQ_CODEL_FLOWS,
TCA_FQ_CODEL_QUANTUM,
__TCA_FQ_CODEL_MAX
};
#define TCA_FQ_CODEL_MAX (__TCA_FQ_CODEL_MAX - 1)
enum {
TCA_FQ_CODEL_XSTATS_QDISC,
TCA_FQ_CODEL_XSTATS_CLASS,
};
struct tc_fq_codel_qd_stats {
__u32 maxpacket; /* largest packet we've seen so far */
__u32 drop_overlimit; /* number of time max qdisc
* packet limit was hit
*/
__u32 ecn_mark; /* number of packets we ECN marked
* instead of being dropped
*/
__u32 new_flow_count; /* number of time packets
* created a 'new flow'
*/
__u32 new_flows_len; /* count of flows in new list */
__u32 old_flows_len; /* count of flows in old list */
};
struct tc_fq_codel_cl_stats {
__s32 deficit;
__u32 ldelay; /* in-queue delay seen by most recently
* dequeued packet
*/
__u32 count;
__u32 lastcount;
__u32 dropping;
__s32 drop_next;
};
struct tc_fq_codel_xstats {
__u32 type;
union {
struct tc_fq_codel_qd_stats qdisc_stats;
struct tc_fq_codel_cl_stats class_stats;
};
};
#endif

Просмотреть файл

@ -261,6 +261,17 @@ config NET_SCH_CODEL
If unsure, say N.
config NET_SCH_FQ_CODEL
tristate "Fair Queue Controlled Delay AQM (FQ_CODEL)"
help
Say Y here if you want to use the FQ Controlled Delay (FQ_CODEL)
packet scheduling algorithm.
To compile this driver as a module, choose M here: the module
will be called sch_fq_codel.
If unsure, say N.
config NET_SCH_INGRESS
tristate "Ingress Qdisc"
depends on NET_CLS_ACT

Просмотреть файл

@ -38,6 +38,7 @@ obj-$(CONFIG_NET_SCH_MQPRIO) += sch_mqprio.o
obj-$(CONFIG_NET_SCH_CHOKE) += sch_choke.o
obj-$(CONFIG_NET_SCH_QFQ) += sch_qfq.o
obj-$(CONFIG_NET_SCH_CODEL) += sch_codel.o
obj-$(CONFIG_NET_SCH_FQ_CODEL) += sch_fq_codel.o
obj-$(CONFIG_NET_CLS_U32) += cls_u32.o
obj-$(CONFIG_NET_CLS_ROUTE4) += cls_route.o

624
net/sched/sch_fq_codel.c Normal file
Просмотреть файл

@ -0,0 +1,624 @@
/*
* Fair Queue CoDel discipline
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Copyright (C) 2012 Eric Dumazet <edumazet@google.com>
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/jhash.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/flow_keys.h>
#include <net/codel.h>
/* Fair Queue CoDel.
*
* Principles :
* Packets are classified (internal classifier or external) on flows.
* This is a Stochastic model (as we use a hash, several flows
* might be hashed on same slot)
* Each flow has a CoDel managed queue.
* Flows are linked onto two (Round Robin) lists,
* so that new flows have priority on old ones.
*
* For a given flow, packets are not reordered (CoDel uses a FIFO)
* head drops only.
* ECN capability is on by default.
* Low memory footprint (64 bytes per flow)
*/
struct fq_codel_flow {
struct sk_buff *head;
struct sk_buff *tail;
struct list_head flowchain;
int deficit;
u32 dropped; /* number of drops (or ECN marks) on this flow */
struct codel_vars cvars;
}; /* please try to keep this structure <= 64 bytes */
struct fq_codel_sched_data {
struct tcf_proto *filter_list; /* optional external classifier */
struct fq_codel_flow *flows; /* Flows table [flows_cnt] */
u32 *backlogs; /* backlog table [flows_cnt] */
u32 flows_cnt; /* number of flows */
u32 perturbation; /* hash perturbation */
u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
struct codel_params cparams;
struct codel_stats cstats;
u32 drop_overlimit;
u32 new_flow_count;
struct list_head new_flows; /* list of new flows */
struct list_head old_flows; /* list of old flows */
};
static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q,
const struct sk_buff *skb)
{
struct flow_keys keys;
unsigned int hash;
skb_flow_dissect(skb, &keys);
hash = jhash_3words((__force u32)keys.dst,
(__force u32)keys.src ^ keys.ip_proto,
(__force u32)keys.ports, q->perturbation);
return ((u64)hash * q->flows_cnt) >> 32;
}
static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
int *qerr)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct tcf_result res;
int result;
if (TC_H_MAJ(skb->priority) == sch->handle &&
TC_H_MIN(skb->priority) > 0 &&
TC_H_MIN(skb->priority) <= q->flows_cnt)
return TC_H_MIN(skb->priority);
if (!q->filter_list)
return fq_codel_hash(q, skb) + 1;
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
result = tc_classify(skb, q->filter_list, &res);
if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
switch (result) {
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
case TC_ACT_SHOT:
return 0;
}
#endif
if (TC_H_MIN(res.classid) <= q->flows_cnt)
return TC_H_MIN(res.classid);
}
return 0;
}
/* helper functions : might be changed when/if skb use a standard list_head */
/* remove one skb from head of slot queue */
static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
{
struct sk_buff *skb = flow->head;
flow->head = skb->next;
skb->next = NULL;
return skb;
}
/* add skb to flow queue (tail add) */
static inline void flow_queue_add(struct fq_codel_flow *flow,
struct sk_buff *skb)
{
if (flow->head == NULL)
flow->head = skb;
else
flow->tail->next = skb;
flow->tail = skb;
skb->next = NULL;
}
static unsigned int fq_codel_drop(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
unsigned int maxbacklog = 0, idx = 0, i, len;
struct fq_codel_flow *flow;
/* Queue is full! Find the fat flow and drop packet from it.
* This might sound expensive, but with 1024 flows, we scan
* 4KB of memory, and we dont need to handle a complex tree
* in fast path (packet queue/enqueue) with many cache misses.
*/
for (i = 0; i < q->flows_cnt; i++) {
if (q->backlogs[i] > maxbacklog) {
maxbacklog = q->backlogs[i];
idx = i;
}
}
flow = &q->flows[idx];
skb = dequeue_head(flow);
len = qdisc_pkt_len(skb);
q->backlogs[idx] -= len;
kfree_skb(skb);
sch->q.qlen--;
sch->qstats.drops++;
sch->qstats.backlog -= len;
flow->dropped++;
return idx;
}
static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
unsigned int idx;
struct fq_codel_flow *flow;
int uninitialized_var(ret);
idx = fq_codel_classify(skb, sch, &ret);
if (idx == 0) {
if (ret & __NET_XMIT_BYPASS)
sch->qstats.drops++;
kfree_skb(skb);
return ret;
}
idx--;
codel_set_enqueue_time(skb);
flow = &q->flows[idx];
flow_queue_add(flow, skb);
q->backlogs[idx] += qdisc_pkt_len(skb);
sch->qstats.backlog += qdisc_pkt_len(skb);
if (list_empty(&flow->flowchain)) {
list_add_tail(&flow->flowchain, &q->new_flows);
codel_vars_init(&flow->cvars);
q->new_flow_count++;
flow->deficit = q->quantum;
flow->dropped = 0;
}
if (++sch->q.qlen < sch->limit)
return NET_XMIT_SUCCESS;
q->drop_overlimit++;
/* Return Congestion Notification only if we dropped a packet
* from this flow.
*/
if (fq_codel_drop(sch) == idx)
return NET_XMIT_CN;
/* As we dropped a packet, better let upper stack know this */
qdisc_tree_decrease_qlen(sch, 1);
return NET_XMIT_SUCCESS;
}
/* This is the specific function called from codel_dequeue()
* to dequeue a packet from queue. Note: backlog is handled in
* codel, we dont need to reduce it here.
*/
static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
{
struct fq_codel_flow *flow;
struct sk_buff *skb = NULL;
flow = container_of(vars, struct fq_codel_flow, cvars);
if (flow->head) {
skb = dequeue_head(flow);
sch->qstats.backlog -= qdisc_pkt_len(skb);
sch->q.qlen--;
}
return skb;
}
static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
struct fq_codel_flow *flow;
struct list_head *head;
u32 prev_drop_count, prev_ecn_mark;
begin:
head = &q->new_flows;
if (list_empty(head)) {
head = &q->old_flows;
if (list_empty(head))
return NULL;
}
flow = list_first_entry(head, struct fq_codel_flow, flowchain);
if (flow->deficit <= 0) {
flow->deficit += q->quantum;
list_move_tail(&flow->flowchain, &q->old_flows);
goto begin;
}
prev_drop_count = q->cstats.drop_count;
prev_ecn_mark = q->cstats.ecn_mark;
skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
dequeue, &q->backlogs[flow - q->flows]);
flow->dropped += q->cstats.drop_count - prev_drop_count;
flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
if (!skb) {
/* force a pass through old_flows to prevent starvation */
if ((head == &q->new_flows) && !list_empty(&q->old_flows))
list_move_tail(&flow->flowchain, &q->old_flows);
else
list_del_init(&flow->flowchain);
goto begin;
}
qdisc_bstats_update(sch, skb);
flow->deficit -= qdisc_pkt_len(skb);
/* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
* or HTB crashes. Defer it for next round.
*/
if (q->cstats.drop_count && sch->q.qlen) {
qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
q->cstats.drop_count = 0;
}
return skb;
}
static void fq_codel_reset(struct Qdisc *sch)
{
struct sk_buff *skb;
while ((skb = fq_codel_dequeue(sch)) != NULL)
kfree_skb(skb);
}
static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
[TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 },
[TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 },
[TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
[TCA_FQ_CODEL_ECN] = { .type = NLA_U32 },
[TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 },
[TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 },
};
static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
int err;
if (!opt)
return -EINVAL;
err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
if (err < 0)
return err;
if (tb[TCA_FQ_CODEL_FLOWS]) {
if (q->flows)
return -EINVAL;
q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
if (!q->flows_cnt ||
q->flows_cnt > 65536)
return -EINVAL;
}
sch_tree_lock(sch);
if (tb[TCA_FQ_CODEL_TARGET]) {
u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
}
if (tb[TCA_FQ_CODEL_INTERVAL]) {
u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
}
if (tb[TCA_FQ_CODEL_LIMIT])
sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
if (tb[TCA_FQ_CODEL_ECN])
q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
if (tb[TCA_FQ_CODEL_QUANTUM])
q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
while (sch->q.qlen > sch->limit) {
struct sk_buff *skb = fq_codel_dequeue(sch);
kfree_skb(skb);
q->cstats.drop_count++;
}
qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
q->cstats.drop_count = 0;
sch_tree_unlock(sch);
return 0;
}
static void *fq_codel_zalloc(size_t sz)
{
void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
if (!ptr)
ptr = vzalloc(sz);
return ptr;
}
static void fq_codel_free(void *addr)
{
if (addr) {
if (is_vmalloc_addr(addr))
vfree(addr);
else
kfree(addr);
}
}
static void fq_codel_destroy(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
tcf_destroy_chain(&q->filter_list);
fq_codel_free(q->backlogs);
fq_codel_free(q->flows);
}
static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
int i;
sch->limit = 10*1024;
q->flows_cnt = 1024;
q->quantum = psched_mtu(qdisc_dev(sch));
q->perturbation = net_random();
INIT_LIST_HEAD(&q->new_flows);
INIT_LIST_HEAD(&q->old_flows);
codel_params_init(&q->cparams);
codel_stats_init(&q->cstats);
q->cparams.ecn = true;
if (opt) {
int err = fq_codel_change(sch, opt);
if (err)
return err;
}
if (!q->flows) {
q->flows = fq_codel_zalloc(q->flows_cnt *
sizeof(struct fq_codel_flow));
if (!q->flows)
return -ENOMEM;
q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
if (!q->backlogs) {
fq_codel_free(q->flows);
return -ENOMEM;
}
for (i = 0; i < q->flows_cnt; i++) {
struct fq_codel_flow *flow = q->flows + i;
INIT_LIST_HEAD(&flow->flowchain);
}
}
if (sch->limit >= 1)
sch->flags |= TCQ_F_CAN_BYPASS;
else
sch->flags &= ~TCQ_F_CAN_BYPASS;
return 0;
}
static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct nlattr *opts;
opts = nla_nest_start(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
codel_time_to_us(q->cparams.target)) ||
nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
sch->limit) ||
nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
codel_time_to_us(q->cparams.interval)) ||
nla_put_u32(skb, TCA_FQ_CODEL_ECN,
q->cparams.ecn) ||
nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
q->quantum) ||
nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
q->flows_cnt))
goto nla_put_failure;
nla_nest_end(skb, opts);
return skb->len;
nla_put_failure:
return -1;
}
static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
struct tc_fq_codel_xstats st = {
.type = TCA_FQ_CODEL_XSTATS_QDISC,
.qdisc_stats.maxpacket = q->cstats.maxpacket,
.qdisc_stats.drop_overlimit = q->drop_overlimit,
.qdisc_stats.ecn_mark = q->cstats.ecn_mark,
.qdisc_stats.new_flow_count = q->new_flow_count,
};
struct list_head *pos;
list_for_each(pos, &q->new_flows)
st.qdisc_stats.new_flows_len++;
list_for_each(pos, &q->old_flows)
st.qdisc_stats.old_flows_len++;
return gnet_stats_copy_app(d, &st, sizeof(st));
}
static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
{
return NULL;
}
static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
{
return 0;
}
static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
u32 classid)
{
/* we cannot bypass queue discipline anymore */
sch->flags &= ~TCQ_F_CAN_BYPASS;
return 0;
}
static void fq_codel_put(struct Qdisc *q, unsigned long cl)
{
}
static struct tcf_proto **fq_codel_find_tcf(struct Qdisc *sch, unsigned long cl)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
if (cl)
return NULL;
return &q->filter_list;
}
static int fq_codel_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 fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
struct gnet_dump *d)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
u32 idx = cl - 1;
struct gnet_stats_queue qs = { 0 };
struct tc_fq_codel_xstats xstats;
if (idx < q->flows_cnt) {
const struct fq_codel_flow *flow = &q->flows[idx];
const struct sk_buff *skb = flow->head;
memset(&xstats, 0, sizeof(xstats));
xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
xstats.class_stats.deficit = flow->deficit;
xstats.class_stats.ldelay =
codel_time_to_us(flow->cvars.ldelay);
xstats.class_stats.count = flow->cvars.count;
xstats.class_stats.lastcount = flow->cvars.lastcount;
xstats.class_stats.dropping = flow->cvars.dropping;
if (flow->cvars.dropping) {
codel_tdiff_t delta = flow->cvars.drop_next -
codel_get_time();
xstats.class_stats.drop_next = (delta >= 0) ?
codel_time_to_us(delta) :
-codel_time_to_us(-delta);
}
while (skb) {
qs.qlen++;
skb = skb->next;
}
qs.backlog = q->backlogs[idx];
qs.drops = flow->dropped;
}
if (gnet_stats_copy_queue(d, &qs) < 0)
return -1;
if (idx < q->flows_cnt)
return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
return 0;
}
static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
unsigned int i;
if (arg->stop)
return;
for (i = 0; i < q->flows_cnt; i++) {
if (list_empty(&q->flows[i].flowchain) ||
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 fq_codel_class_ops = {
.leaf = fq_codel_leaf,
.get = fq_codel_get,
.put = fq_codel_put,
.tcf_chain = fq_codel_find_tcf,
.bind_tcf = fq_codel_bind,
.unbind_tcf = fq_codel_put,
.dump = fq_codel_dump_class,
.dump_stats = fq_codel_dump_class_stats,
.walk = fq_codel_walk,
};
static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
.cl_ops = &fq_codel_class_ops,
.id = "fq_codel",
.priv_size = sizeof(struct fq_codel_sched_data),
.enqueue = fq_codel_enqueue,
.dequeue = fq_codel_dequeue,
.peek = qdisc_peek_dequeued,
.drop = fq_codel_drop,
.init = fq_codel_init,
.reset = fq_codel_reset,
.destroy = fq_codel_destroy,
.change = fq_codel_change,
.dump = fq_codel_dump,
.dump_stats = fq_codel_dump_stats,
.owner = THIS_MODULE,
};
static int __init fq_codel_module_init(void)
{
return register_qdisc(&fq_codel_qdisc_ops);
}
static void __exit fq_codel_module_exit(void)
{
unregister_qdisc(&fq_codel_qdisc_ops);
}
module_init(fq_codel_module_init)
module_exit(fq_codel_module_exit)
MODULE_AUTHOR("Eric Dumazet");
MODULE_LICENSE("GPL");