linux-brain/net/sched/sch_fq_codel.c
Michal Kubecek ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:03:44 -04:00

739 lines
19 KiB
C

/*
* 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) 2012,2015 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/pkt_cls.h>
#include <net/codel.h>
#include <net/codel_impl.h>
#include <net/codel_qdisc.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 __rcu *filter_list; /* optional external classifier */
struct tcf_block *block;
struct fq_codel_flow *flows; /* Flows table [flows_cnt] */
u32 *backlogs; /* backlog table [flows_cnt] */
u32 flows_cnt; /* number of flows */
u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
u32 drop_batch_size;
u32 memory_limit;
struct codel_params cparams;
struct codel_stats cstats;
u32 memory_usage;
u32 drop_overmemory;
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,
struct sk_buff *skb)
{
return reciprocal_scale(skb_get_hash(skb), q->flows_cnt);
}
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_proto *filter;
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);
filter = rcu_dereference_bh(q->filter_list);
if (!filter)
return fq_codel_hash(q, skb) + 1;
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
result = tcf_classify(skb, filter, &res, false);
if (result >= 0) {
#ifdef CONFIG_NET_CLS_ACT
switch (result) {
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
case TC_ACT_TRAP:
*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
/* fall through */
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_mark_not_on_list(skb);
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, unsigned int max_packets,
struct sk_buff **to_free)
{
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;
unsigned int threshold;
unsigned int mem = 0;
/* Queue is full! Find the fat flow and drop packet(s) 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.
* In stress mode, we'll try to drop 64 packets from the flow,
* amortizing this linear lookup to one cache line per drop.
*/
for (i = 0; i < q->flows_cnt; i++) {
if (q->backlogs[i] > maxbacklog) {
maxbacklog = q->backlogs[i];
idx = i;
}
}
/* Our goal is to drop half of this fat flow backlog */
threshold = maxbacklog >> 1;
flow = &q->flows[idx];
len = 0;
i = 0;
do {
skb = dequeue_head(flow);
len += qdisc_pkt_len(skb);
mem += get_codel_cb(skb)->mem_usage;
__qdisc_drop(skb, to_free);
} while (++i < max_packets && len < threshold);
flow->dropped += i;
q->backlogs[idx] -= len;
q->memory_usage -= mem;
sch->qstats.drops += i;
sch->qstats.backlog -= len;
sch->q.qlen -= i;
return idx;
}
static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
unsigned int idx, prev_backlog, prev_qlen;
struct fq_codel_flow *flow;
int uninitialized_var(ret);
unsigned int pkt_len;
bool memory_limited;
idx = fq_codel_classify(skb, sch, &ret);
if (idx == 0) {
if (ret & __NET_XMIT_BYPASS)
qdisc_qstats_drop(sch);
__qdisc_drop(skb, to_free);
return ret;
}
idx--;
codel_set_enqueue_time(skb);
flow = &q->flows[idx];
flow_queue_add(flow, skb);
q->backlogs[idx] += qdisc_pkt_len(skb);
qdisc_qstats_backlog_inc(sch, skb);
if (list_empty(&flow->flowchain)) {
list_add_tail(&flow->flowchain, &q->new_flows);
q->new_flow_count++;
flow->deficit = q->quantum;
flow->dropped = 0;
}
get_codel_cb(skb)->mem_usage = skb->truesize;
q->memory_usage += get_codel_cb(skb)->mem_usage;
memory_limited = q->memory_usage > q->memory_limit;
if (++sch->q.qlen <= sch->limit && !memory_limited)
return NET_XMIT_SUCCESS;
prev_backlog = sch->qstats.backlog;
prev_qlen = sch->q.qlen;
/* save this packet length as it might be dropped by fq_codel_drop() */
pkt_len = qdisc_pkt_len(skb);
/* fq_codel_drop() is quite expensive, as it performs a linear search
* in q->backlogs[] to find a fat flow.
* So instead of dropping a single packet, drop half of its backlog
* with a 64 packets limit to not add a too big cpu spike here.
*/
ret = fq_codel_drop(sch, q->drop_batch_size, to_free);
prev_qlen -= sch->q.qlen;
prev_backlog -= sch->qstats.backlog;
q->drop_overlimit += prev_qlen;
if (memory_limited)
q->drop_overmemory += prev_qlen;
/* As we dropped packet(s), better let upper stack know this.
* If we dropped a packet for this flow, return NET_XMIT_CN,
* but in this case, our parents wont increase their backlogs.
*/
if (ret == idx) {
qdisc_tree_reduce_backlog(sch, prev_qlen - 1,
prev_backlog - pkt_len);
return NET_XMIT_CN;
}
qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog);
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_func(struct codel_vars *vars, void *ctx)
{
struct Qdisc *sch = ctx;
struct fq_codel_sched_data *q = qdisc_priv(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);
q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
q->memory_usage -= get_codel_cb(skb)->mem_usage;
sch->q.qlen--;
sch->qstats.backlog -= qdisc_pkt_len(skb);
}
return skb;
}
static void drop_func(struct sk_buff *skb, void *ctx)
{
struct Qdisc *sch = ctx;
kfree_skb(skb);
qdisc_qstats_drop(sch);
}
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, &sch->qstats.backlog, &q->cparams,
&flow->cvars, &q->cstats, qdisc_pkt_len,
codel_get_enqueue_time, drop_func, dequeue_func);
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_reduce_backlog() if our qlen is 0,
* or HTB crashes. Defer it for next round.
*/
if (q->cstats.drop_count && sch->q.qlen) {
qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
q->cstats.drop_len);
q->cstats.drop_count = 0;
q->cstats.drop_len = 0;
}
return skb;
}
static void fq_codel_flow_purge(struct fq_codel_flow *flow)
{
rtnl_kfree_skbs(flow->head, flow->tail);
flow->head = NULL;
}
static void fq_codel_reset(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
int i;
INIT_LIST_HEAD(&q->new_flows);
INIT_LIST_HEAD(&q->old_flows);
for (i = 0; i < q->flows_cnt; i++) {
struct fq_codel_flow *flow = q->flows + i;
fq_codel_flow_purge(flow);
INIT_LIST_HEAD(&flow->flowchain);
codel_vars_init(&flow->cvars);
}
memset(q->backlogs, 0, q->flows_cnt * sizeof(u32));
sch->q.qlen = 0;
sch->qstats.backlog = 0;
q->memory_usage = 0;
}
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 },
[TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 },
[TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 },
[TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 },
};
static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
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,
NULL);
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_CE_THRESHOLD]) {
u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]);
q->cparams.ce_threshold = (val * 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]));
if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])
q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]));
if (tb[TCA_FQ_CODEL_MEMORY_LIMIT])
q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT]));
while (sch->q.qlen > sch->limit ||
q->memory_usage > q->memory_limit) {
struct sk_buff *skb = fq_codel_dequeue(sch);
q->cstats.drop_len += qdisc_pkt_len(skb);
rtnl_kfree_skbs(skb, skb);
q->cstats.drop_count++;
}
qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len);
q->cstats.drop_count = 0;
q->cstats.drop_len = 0;
sch_tree_unlock(sch);
return 0;
}
static void fq_codel_destroy(struct Qdisc *sch)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
tcf_block_put(q->block);
kvfree(q->backlogs);
kvfree(q->flows);
}
static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
int i;
int err;
sch->limit = 10*1024;
q->flows_cnt = 1024;
q->memory_limit = 32 << 20; /* 32 MBytes */
q->drop_batch_size = 64;
q->quantum = psched_mtu(qdisc_dev(sch));
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;
q->cparams.mtu = psched_mtu(qdisc_dev(sch));
if (opt) {
err = fq_codel_change(sch, opt, extack);
if (err)
goto init_failure;
}
err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
if (err)
goto init_failure;
if (!q->flows) {
q->flows = kvcalloc(q->flows_cnt,
sizeof(struct fq_codel_flow),
GFP_KERNEL);
if (!q->flows) {
err = -ENOMEM;
goto init_failure;
}
q->backlogs = kvcalloc(q->flows_cnt, sizeof(u32), GFP_KERNEL);
if (!q->backlogs) {
err = -ENOMEM;
goto alloc_failure;
}
for (i = 0; i < q->flows_cnt; i++) {
struct fq_codel_flow *flow = q->flows + i;
INIT_LIST_HEAD(&flow->flowchain);
codel_vars_init(&flow->cvars);
}
}
if (sch->limit >= 1)
sch->flags |= TCQ_F_CAN_BYPASS;
else
sch->flags &= ~TCQ_F_CAN_BYPASS;
return 0;
alloc_failure:
kvfree(q->flows);
q->flows = NULL;
init_failure:
q->flows_cnt = 0;
return err;
}
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_noflag(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_DROP_BATCH_SIZE,
q->drop_batch_size) ||
nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT,
q->memory_limit) ||
nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
q->flows_cnt))
goto nla_put_failure;
if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD &&
nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD,
codel_time_to_us(q->cparams.ce_threshold)))
goto nla_put_failure;
return nla_nest_end(skb, opts);
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,
};
struct list_head *pos;
st.qdisc_stats.maxpacket = q->cstats.maxpacket;
st.qdisc_stats.drop_overlimit = q->drop_overlimit;
st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
st.qdisc_stats.new_flow_count = q->new_flow_count;
st.qdisc_stats.ce_mark = q->cstats.ce_mark;
st.qdisc_stats.memory_usage = q->memory_usage;
st.qdisc_stats.drop_overmemory = q->drop_overmemory;
sch_tree_lock(sch);
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++;
sch_tree_unlock(sch);
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_find(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_unbind(struct Qdisc *q, unsigned long cl)
{
}
static struct tcf_block *fq_codel_tcf_block(struct Qdisc *sch, unsigned long cl,
struct netlink_ext_ack *extack)
{
struct fq_codel_sched_data *q = qdisc_priv(sch);
if (cl)
return NULL;
return q->block;
}
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;
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);
}
if (flow->head) {
sch_tree_lock(sch);
skb = flow->head;
while (skb) {
qs.qlen++;
skb = skb->next;
}
sch_tree_unlock(sch);
}
qs.backlog = q->backlogs[idx];
qs.drops = flow->dropped;
}
if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 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,
.find = fq_codel_find,
.tcf_block = fq_codel_tcf_block,
.bind_tcf = fq_codel_bind,
.unbind_tcf = fq_codel_unbind,
.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,
.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");