linux/net/sched/sch_fq.c
Zhengchao Shao a102c8973d net: sched: remove redundant NULL check in change hook function
Currently, the change function can be called by two ways. The one way is
that qdisc_change() will call it. Before calling change function,
qdisc_change() ensures tca[TCA_OPTIONS] is not empty. The other way is
that .init() will call it. The opt parameter is also checked before
calling change function in .init(). Therefore, it's no need to check the
input parameter opt in change function.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/r/20220829071219.208646-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-01 08:06:45 +02:00

1076 lines
27 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing)
*
* Copyright (C) 2013-2015 Eric Dumazet <edumazet@google.com>
*
* Meant to be mostly used for locally generated traffic :
* Fast classification depends on skb->sk being set before reaching us.
* If not, (router workload), we use rxhash as fallback, with 32 bits wide hash.
* All packets belonging to a socket are considered as a 'flow'.
*
* Flows are dynamically allocated and stored in a hash table of RB trees
* They are also part of one Round Robin 'queues' (new or old flows)
*
* Burst avoidance (aka pacing) capability :
*
* Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a
* bunch of packets, and this packet scheduler adds delay between
* packets to respect rate limitation.
*
* enqueue() :
* - lookup one RB tree (out of 1024 or more) to find the flow.
* If non existent flow, create it, add it to the tree.
* Add skb to the per flow list of skb (fifo).
* - Use a special fifo for high prio packets
*
* dequeue() : serves flows in Round Robin
* Note : When a flow becomes empty, we do not immediately remove it from
* rb trees, for performance reasons (its expected to send additional packets,
* or SLAB cache will reuse socket for another flow)
*/
#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/slab.h>
#include <linux/rbtree.h>
#include <linux/hash.h>
#include <linux/prefetch.h>
#include <linux/vmalloc.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <net/tcp.h>
struct fq_skb_cb {
u64 time_to_send;
};
static inline struct fq_skb_cb *fq_skb_cb(struct sk_buff *skb)
{
qdisc_cb_private_validate(skb, sizeof(struct fq_skb_cb));
return (struct fq_skb_cb *)qdisc_skb_cb(skb)->data;
}
/*
* Per flow structure, dynamically allocated.
* If packets have monotically increasing time_to_send, they are placed in O(1)
* in linear list (head,tail), otherwise are placed in a rbtree (t_root).
*/
struct fq_flow {
/* First cache line : used in fq_gc(), fq_enqueue(), fq_dequeue() */
struct rb_root t_root;
struct sk_buff *head; /* list of skbs for this flow : first skb */
union {
struct sk_buff *tail; /* last skb in the list */
unsigned long age; /* (jiffies | 1UL) when flow was emptied, for gc */
};
struct rb_node fq_node; /* anchor in fq_root[] trees */
struct sock *sk;
u32 socket_hash; /* sk_hash */
int qlen; /* number of packets in flow queue */
/* Second cache line, used in fq_dequeue() */
int credit;
/* 32bit hole on 64bit arches */
struct fq_flow *next; /* next pointer in RR lists */
struct rb_node rate_node; /* anchor in q->delayed tree */
u64 time_next_packet;
} ____cacheline_aligned_in_smp;
struct fq_flow_head {
struct fq_flow *first;
struct fq_flow *last;
};
struct fq_sched_data {
struct fq_flow_head new_flows;
struct fq_flow_head old_flows;
struct rb_root delayed; /* for rate limited flows */
u64 time_next_delayed_flow;
u64 ktime_cache; /* copy of last ktime_get_ns() */
unsigned long unthrottle_latency_ns;
struct fq_flow internal; /* for non classified or high prio packets */
u32 quantum;
u32 initial_quantum;
u32 flow_refill_delay;
u32 flow_plimit; /* max packets per flow */
unsigned long flow_max_rate; /* optional max rate per flow */
u64 ce_threshold;
u64 horizon; /* horizon in ns */
u32 orphan_mask; /* mask for orphaned skb */
u32 low_rate_threshold;
struct rb_root *fq_root;
u8 rate_enable;
u8 fq_trees_log;
u8 horizon_drop;
u32 flows;
u32 inactive_flows;
u32 throttled_flows;
u64 stat_gc_flows;
u64 stat_internal_packets;
u64 stat_throttled;
u64 stat_ce_mark;
u64 stat_horizon_drops;
u64 stat_horizon_caps;
u64 stat_flows_plimit;
u64 stat_pkts_too_long;
u64 stat_allocation_errors;
u32 timer_slack; /* hrtimer slack in ns */
struct qdisc_watchdog watchdog;
};
/*
* f->tail and f->age share the same location.
* We can use the low order bit to differentiate if this location points
* to a sk_buff or contains a jiffies value, if we force this value to be odd.
* This assumes f->tail low order bit must be 0 since alignof(struct sk_buff) >= 2
*/
static void fq_flow_set_detached(struct fq_flow *f)
{
f->age = jiffies | 1UL;
}
static bool fq_flow_is_detached(const struct fq_flow *f)
{
return !!(f->age & 1UL);
}
/* special value to mark a throttled flow (not on old/new list) */
static struct fq_flow throttled;
static bool fq_flow_is_throttled(const struct fq_flow *f)
{
return f->next == &throttled;
}
static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
{
if (head->first)
head->last->next = flow;
else
head->first = flow;
head->last = flow;
flow->next = NULL;
}
static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f)
{
rb_erase(&f->rate_node, &q->delayed);
q->throttled_flows--;
fq_flow_add_tail(&q->old_flows, f);
}
static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
{
struct rb_node **p = &q->delayed.rb_node, *parent = NULL;
while (*p) {
struct fq_flow *aux;
parent = *p;
aux = rb_entry(parent, struct fq_flow, rate_node);
if (f->time_next_packet >= aux->time_next_packet)
p = &parent->rb_right;
else
p = &parent->rb_left;
}
rb_link_node(&f->rate_node, parent, p);
rb_insert_color(&f->rate_node, &q->delayed);
q->throttled_flows++;
q->stat_throttled++;
f->next = &throttled;
if (q->time_next_delayed_flow > f->time_next_packet)
q->time_next_delayed_flow = f->time_next_packet;
}
static struct kmem_cache *fq_flow_cachep __read_mostly;
/* limit number of collected flows per round */
#define FQ_GC_MAX 8
#define FQ_GC_AGE (3*HZ)
static bool fq_gc_candidate(const struct fq_flow *f)
{
return fq_flow_is_detached(f) &&
time_after(jiffies, f->age + FQ_GC_AGE);
}
static void fq_gc(struct fq_sched_data *q,
struct rb_root *root,
struct sock *sk)
{
struct rb_node **p, *parent;
void *tofree[FQ_GC_MAX];
struct fq_flow *f;
int i, fcnt = 0;
p = &root->rb_node;
parent = NULL;
while (*p) {
parent = *p;
f = rb_entry(parent, struct fq_flow, fq_node);
if (f->sk == sk)
break;
if (fq_gc_candidate(f)) {
tofree[fcnt++] = f;
if (fcnt == FQ_GC_MAX)
break;
}
if (f->sk > sk)
p = &parent->rb_right;
else
p = &parent->rb_left;
}
if (!fcnt)
return;
for (i = fcnt; i > 0; ) {
f = tofree[--i];
rb_erase(&f->fq_node, root);
}
q->flows -= fcnt;
q->inactive_flows -= fcnt;
q->stat_gc_flows += fcnt;
kmem_cache_free_bulk(fq_flow_cachep, fcnt, tofree);
}
static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
{
struct rb_node **p, *parent;
struct sock *sk = skb->sk;
struct rb_root *root;
struct fq_flow *f;
/* warning: no starvation prevention... */
if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
return &q->internal;
/* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
* or a listener (SYNCOOKIE mode)
* 1) request sockets are not full blown,
* they do not contain sk_pacing_rate
* 2) They are not part of a 'flow' yet
* 3) We do not want to rate limit them (eg SYNFLOOD attack),
* especially if the listener set SO_MAX_PACING_RATE
* 4) We pretend they are orphaned
*/
if (!sk || sk_listener(sk)) {
unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
/* By forcing low order bit to 1, we make sure to not
* collide with a local flow (socket pointers are word aligned)
*/
sk = (struct sock *)((hash << 1) | 1UL);
skb_orphan(skb);
} else if (sk->sk_state == TCP_CLOSE) {
unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
/*
* Sockets in TCP_CLOSE are non connected.
* Typical use case is UDP sockets, they can send packets
* with sendto() to many different destinations.
* We probably could use a generic bit advertising
* non connected sockets, instead of sk_state == TCP_CLOSE,
* if we care enough.
*/
sk = (struct sock *)((hash << 1) | 1UL);
}
root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)];
if (q->flows >= (2U << q->fq_trees_log) &&
q->inactive_flows > q->flows/2)
fq_gc(q, root, sk);
p = &root->rb_node;
parent = NULL;
while (*p) {
parent = *p;
f = rb_entry(parent, struct fq_flow, fq_node);
if (f->sk == sk) {
/* socket might have been reallocated, so check
* if its sk_hash is the same.
* It not, we need to refill credit with
* initial quantum
*/
if (unlikely(skb->sk == sk &&
f->socket_hash != sk->sk_hash)) {
f->credit = q->initial_quantum;
f->socket_hash = sk->sk_hash;
if (q->rate_enable)
smp_store_release(&sk->sk_pacing_status,
SK_PACING_FQ);
if (fq_flow_is_throttled(f))
fq_flow_unset_throttled(q, f);
f->time_next_packet = 0ULL;
}
return f;
}
if (f->sk > sk)
p = &parent->rb_right;
else
p = &parent->rb_left;
}
f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
if (unlikely(!f)) {
q->stat_allocation_errors++;
return &q->internal;
}
/* f->t_root is already zeroed after kmem_cache_zalloc() */
fq_flow_set_detached(f);
f->sk = sk;
if (skb->sk == sk) {
f->socket_hash = sk->sk_hash;
if (q->rate_enable)
smp_store_release(&sk->sk_pacing_status,
SK_PACING_FQ);
}
f->credit = q->initial_quantum;
rb_link_node(&f->fq_node, parent, p);
rb_insert_color(&f->fq_node, root);
q->flows++;
q->inactive_flows++;
return f;
}
static struct sk_buff *fq_peek(struct fq_flow *flow)
{
struct sk_buff *skb = skb_rb_first(&flow->t_root);
struct sk_buff *head = flow->head;
if (!skb)
return head;
if (!head)
return skb;
if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send)
return skb;
return head;
}
static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow,
struct sk_buff *skb)
{
if (skb == flow->head) {
flow->head = skb->next;
} else {
rb_erase(&skb->rbnode, &flow->t_root);
skb->dev = qdisc_dev(sch);
}
}
/* Remove one skb from flow queue.
* This skb must be the return value of prior fq_peek().
*/
static void fq_dequeue_skb(struct Qdisc *sch, struct fq_flow *flow,
struct sk_buff *skb)
{
fq_erase_head(sch, flow, skb);
skb_mark_not_on_list(skb);
flow->qlen--;
qdisc_qstats_backlog_dec(sch, skb);
sch->q.qlen--;
}
static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
{
struct rb_node **p, *parent;
struct sk_buff *head, *aux;
head = flow->head;
if (!head ||
fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) {
if (!head)
flow->head = skb;
else
flow->tail->next = skb;
flow->tail = skb;
skb->next = NULL;
return;
}
p = &flow->t_root.rb_node;
parent = NULL;
while (*p) {
parent = *p;
aux = rb_to_skb(parent);
if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send)
p = &parent->rb_right;
else
p = &parent->rb_left;
}
rb_link_node(&skb->rbnode, parent, p);
rb_insert_color(&skb->rbnode, &flow->t_root);
}
static bool fq_packet_beyond_horizon(const struct sk_buff *skb,
const struct fq_sched_data *q)
{
return unlikely((s64)skb->tstamp > (s64)(q->ktime_cache + q->horizon));
}
static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct fq_flow *f;
if (unlikely(sch->q.qlen >= sch->limit))
return qdisc_drop(skb, sch, to_free);
if (!skb->tstamp) {
fq_skb_cb(skb)->time_to_send = q->ktime_cache = ktime_get_ns();
} else {
/* Check if packet timestamp is too far in the future.
* Try first if our cached value, to avoid ktime_get_ns()
* cost in most cases.
*/
if (fq_packet_beyond_horizon(skb, q)) {
/* Refresh our cache and check another time */
q->ktime_cache = ktime_get_ns();
if (fq_packet_beyond_horizon(skb, q)) {
if (q->horizon_drop) {
q->stat_horizon_drops++;
return qdisc_drop(skb, sch, to_free);
}
q->stat_horizon_caps++;
skb->tstamp = q->ktime_cache + q->horizon;
}
}
fq_skb_cb(skb)->time_to_send = skb->tstamp;
}
f = fq_classify(skb, q);
if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
q->stat_flows_plimit++;
return qdisc_drop(skb, sch, to_free);
}
f->qlen++;
qdisc_qstats_backlog_inc(sch, skb);
if (fq_flow_is_detached(f)) {
fq_flow_add_tail(&q->new_flows, f);
if (time_after(jiffies, f->age + q->flow_refill_delay))
f->credit = max_t(u32, f->credit, q->quantum);
q->inactive_flows--;
}
/* Note: this overwrites f->age */
flow_queue_add(f, skb);
if (unlikely(f == &q->internal)) {
q->stat_internal_packets++;
}
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
static void fq_check_throttled(struct fq_sched_data *q, u64 now)
{
unsigned long sample;
struct rb_node *p;
if (q->time_next_delayed_flow > now)
return;
/* Update unthrottle latency EWMA.
* This is cheap and can help diagnosing timer/latency problems.
*/
sample = (unsigned long)(now - q->time_next_delayed_flow);
q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3;
q->unthrottle_latency_ns += sample >> 3;
q->time_next_delayed_flow = ~0ULL;
while ((p = rb_first(&q->delayed)) != NULL) {
struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node);
if (f->time_next_packet > now) {
q->time_next_delayed_flow = f->time_next_packet;
break;
}
fq_flow_unset_throttled(q, f);
}
}
static struct sk_buff *fq_dequeue(struct Qdisc *sch)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct fq_flow_head *head;
struct sk_buff *skb;
struct fq_flow *f;
unsigned long rate;
u32 plen;
u64 now;
if (!sch->q.qlen)
return NULL;
skb = fq_peek(&q->internal);
if (unlikely(skb)) {
fq_dequeue_skb(sch, &q->internal, skb);
goto out;
}
q->ktime_cache = now = ktime_get_ns();
fq_check_throttled(q, now);
begin:
head = &q->new_flows;
if (!head->first) {
head = &q->old_flows;
if (!head->first) {
if (q->time_next_delayed_flow != ~0ULL)
qdisc_watchdog_schedule_range_ns(&q->watchdog,
q->time_next_delayed_flow,
q->timer_slack);
return NULL;
}
}
f = head->first;
if (f->credit <= 0) {
f->credit += q->quantum;
head->first = f->next;
fq_flow_add_tail(&q->old_flows, f);
goto begin;
}
skb = fq_peek(f);
if (skb) {
u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send,
f->time_next_packet);
if (now < time_next_packet) {
head->first = f->next;
f->time_next_packet = time_next_packet;
fq_flow_set_throttled(q, f);
goto begin;
}
prefetch(&skb->end);
if ((s64)(now - time_next_packet - q->ce_threshold) > 0) {
INET_ECN_set_ce(skb);
q->stat_ce_mark++;
}
fq_dequeue_skb(sch, f, skb);
} else {
head->first = f->next;
/* force a pass through old_flows to prevent starvation */
if ((head == &q->new_flows) && q->old_flows.first) {
fq_flow_add_tail(&q->old_flows, f);
} else {
fq_flow_set_detached(f);
q->inactive_flows++;
}
goto begin;
}
plen = qdisc_pkt_len(skb);
f->credit -= plen;
if (!q->rate_enable)
goto out;
rate = q->flow_max_rate;
/* If EDT time was provided for this skb, we need to
* update f->time_next_packet only if this qdisc enforces
* a flow max rate.
*/
if (!skb->tstamp) {
if (skb->sk)
rate = min(skb->sk->sk_pacing_rate, rate);
if (rate <= q->low_rate_threshold) {
f->credit = 0;
} else {
plen = max(plen, q->quantum);
if (f->credit > 0)
goto out;
}
}
if (rate != ~0UL) {
u64 len = (u64)plen * NSEC_PER_SEC;
if (likely(rate))
len = div64_ul(len, rate);
/* Since socket rate can change later,
* clamp the delay to 1 second.
* Really, providers of too big packets should be fixed !
*/
if (unlikely(len > NSEC_PER_SEC)) {
len = NSEC_PER_SEC;
q->stat_pkts_too_long++;
}
/* Account for schedule/timers drifts.
* f->time_next_packet was set when prior packet was sent,
* and current time (@now) can be too late by tens of us.
*/
if (f->time_next_packet)
len -= min(len/2, now - f->time_next_packet);
f->time_next_packet = now + len;
}
out:
qdisc_bstats_update(sch, skb);
return skb;
}
static void fq_flow_purge(struct fq_flow *flow)
{
struct rb_node *p = rb_first(&flow->t_root);
while (p) {
struct sk_buff *skb = rb_to_skb(p);
p = rb_next(p);
rb_erase(&skb->rbnode, &flow->t_root);
rtnl_kfree_skbs(skb, skb);
}
rtnl_kfree_skbs(flow->head, flow->tail);
flow->head = NULL;
flow->qlen = 0;
}
static void fq_reset(struct Qdisc *sch)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct rb_root *root;
struct rb_node *p;
struct fq_flow *f;
unsigned int idx;
sch->q.qlen = 0;
sch->qstats.backlog = 0;
fq_flow_purge(&q->internal);
if (!q->fq_root)
return;
for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
root = &q->fq_root[idx];
while ((p = rb_first(root)) != NULL) {
f = rb_entry(p, struct fq_flow, fq_node);
rb_erase(p, root);
fq_flow_purge(f);
kmem_cache_free(fq_flow_cachep, f);
}
}
q->new_flows.first = NULL;
q->old_flows.first = NULL;
q->delayed = RB_ROOT;
q->flows = 0;
q->inactive_flows = 0;
q->throttled_flows = 0;
}
static void fq_rehash(struct fq_sched_data *q,
struct rb_root *old_array, u32 old_log,
struct rb_root *new_array, u32 new_log)
{
struct rb_node *op, **np, *parent;
struct rb_root *oroot, *nroot;
struct fq_flow *of, *nf;
int fcnt = 0;
u32 idx;
for (idx = 0; idx < (1U << old_log); idx++) {
oroot = &old_array[idx];
while ((op = rb_first(oroot)) != NULL) {
rb_erase(op, oroot);
of = rb_entry(op, struct fq_flow, fq_node);
if (fq_gc_candidate(of)) {
fcnt++;
kmem_cache_free(fq_flow_cachep, of);
continue;
}
nroot = &new_array[hash_ptr(of->sk, new_log)];
np = &nroot->rb_node;
parent = NULL;
while (*np) {
parent = *np;
nf = rb_entry(parent, struct fq_flow, fq_node);
BUG_ON(nf->sk == of->sk);
if (nf->sk > of->sk)
np = &parent->rb_right;
else
np = &parent->rb_left;
}
rb_link_node(&of->fq_node, parent, np);
rb_insert_color(&of->fq_node, nroot);
}
}
q->flows -= fcnt;
q->inactive_flows -= fcnt;
q->stat_gc_flows += fcnt;
}
static void fq_free(void *addr)
{
kvfree(addr);
}
static int fq_resize(struct Qdisc *sch, u32 log)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct rb_root *array;
void *old_fq_root;
u32 idx;
if (q->fq_root && log == q->fq_trees_log)
return 0;
/* If XPS was setup, we can allocate memory on right NUMA node */
array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL,
netdev_queue_numa_node_read(sch->dev_queue));
if (!array)
return -ENOMEM;
for (idx = 0; idx < (1U << log); idx++)
array[idx] = RB_ROOT;
sch_tree_lock(sch);
old_fq_root = q->fq_root;
if (old_fq_root)
fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
q->fq_root = array;
q->fq_trees_log = log;
sch_tree_unlock(sch);
fq_free(old_fq_root);
return 0;
}
static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
[TCA_FQ_UNSPEC] = { .strict_start_type = TCA_FQ_TIMER_SLACK },
[TCA_FQ_PLIMIT] = { .type = NLA_U32 },
[TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 },
[TCA_FQ_QUANTUM] = { .type = NLA_U32 },
[TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 },
[TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 },
[TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 },
[TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 },
[TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 },
[TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 },
[TCA_FQ_ORPHAN_MASK] = { .type = NLA_U32 },
[TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 },
[TCA_FQ_CE_THRESHOLD] = { .type = NLA_U32 },
[TCA_FQ_TIMER_SLACK] = { .type = NLA_U32 },
[TCA_FQ_HORIZON] = { .type = NLA_U32 },
[TCA_FQ_HORIZON_DROP] = { .type = NLA_U8 },
};
static int fq_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct nlattr *tb[TCA_FQ_MAX + 1];
int err, drop_count = 0;
unsigned drop_len = 0;
u32 fq_log;
err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy,
NULL);
if (err < 0)
return err;
sch_tree_lock(sch);
fq_log = q->fq_trees_log;
if (tb[TCA_FQ_BUCKETS_LOG]) {
u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);
if (nval >= 1 && nval <= ilog2(256*1024))
fq_log = nval;
else
err = -EINVAL;
}
if (tb[TCA_FQ_PLIMIT])
sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
if (tb[TCA_FQ_FLOW_PLIMIT])
q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
if (tb[TCA_FQ_QUANTUM]) {
u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
if (quantum > 0 && quantum <= (1 << 20)) {
q->quantum = quantum;
} else {
NL_SET_ERR_MSG_MOD(extack, "invalid quantum");
err = -EINVAL;
}
}
if (tb[TCA_FQ_INITIAL_QUANTUM])
q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
pr_warn_ratelimited("sch_fq: defrate %u ignored.\n",
nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]));
if (tb[TCA_FQ_FLOW_MAX_RATE]) {
u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);
q->flow_max_rate = (rate == ~0U) ? ~0UL : rate;
}
if (tb[TCA_FQ_LOW_RATE_THRESHOLD])
q->low_rate_threshold =
nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD]);
if (tb[TCA_FQ_RATE_ENABLE]) {
u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);
if (enable <= 1)
q->rate_enable = enable;
else
err = -EINVAL;
}
if (tb[TCA_FQ_FLOW_REFILL_DELAY]) {
u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ;
q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
}
if (tb[TCA_FQ_ORPHAN_MASK])
q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]);
if (tb[TCA_FQ_CE_THRESHOLD])
q->ce_threshold = (u64)NSEC_PER_USEC *
nla_get_u32(tb[TCA_FQ_CE_THRESHOLD]);
if (tb[TCA_FQ_TIMER_SLACK])
q->timer_slack = nla_get_u32(tb[TCA_FQ_TIMER_SLACK]);
if (tb[TCA_FQ_HORIZON])
q->horizon = (u64)NSEC_PER_USEC *
nla_get_u32(tb[TCA_FQ_HORIZON]);
if (tb[TCA_FQ_HORIZON_DROP])
q->horizon_drop = nla_get_u8(tb[TCA_FQ_HORIZON_DROP]);
if (!err) {
sch_tree_unlock(sch);
err = fq_resize(sch, fq_log);
sch_tree_lock(sch);
}
while (sch->q.qlen > sch->limit) {
struct sk_buff *skb = fq_dequeue(sch);
if (!skb)
break;
drop_len += qdisc_pkt_len(skb);
rtnl_kfree_skbs(skb, skb);
drop_count++;
}
qdisc_tree_reduce_backlog(sch, drop_count, drop_len);
sch_tree_unlock(sch);
return err;
}
static void fq_destroy(struct Qdisc *sch)
{
struct fq_sched_data *q = qdisc_priv(sch);
fq_reset(sch);
fq_free(q->fq_root);
qdisc_watchdog_cancel(&q->watchdog);
}
static int fq_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct fq_sched_data *q = qdisc_priv(sch);
int err;
sch->limit = 10000;
q->flow_plimit = 100;
q->quantum = 2 * psched_mtu(qdisc_dev(sch));
q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
q->flow_refill_delay = msecs_to_jiffies(40);
q->flow_max_rate = ~0UL;
q->time_next_delayed_flow = ~0ULL;
q->rate_enable = 1;
q->new_flows.first = NULL;
q->old_flows.first = NULL;
q->delayed = RB_ROOT;
q->fq_root = NULL;
q->fq_trees_log = ilog2(1024);
q->orphan_mask = 1024 - 1;
q->low_rate_threshold = 550000 / 8;
q->timer_slack = 10 * NSEC_PER_USEC; /* 10 usec of hrtimer slack */
q->horizon = 10ULL * NSEC_PER_SEC; /* 10 seconds */
q->horizon_drop = 1; /* by default, drop packets beyond horizon */
/* Default ce_threshold of 4294 seconds */
q->ce_threshold = (u64)NSEC_PER_USEC * ~0U;
qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC);
if (opt)
err = fq_change(sch, opt, extack);
else
err = fq_resize(sch, q->fq_trees_log);
return err;
}
static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct fq_sched_data *q = qdisc_priv(sch);
u64 ce_threshold = q->ce_threshold;
u64 horizon = q->horizon;
struct nlattr *opts;
opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
/* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */
do_div(ce_threshold, NSEC_PER_USEC);
do_div(horizon, NSEC_PER_USEC);
if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE,
min_t(unsigned long, q->flow_max_rate, ~0U)) ||
nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY,
jiffies_to_usecs(q->flow_refill_delay)) ||
nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) ||
nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD,
q->low_rate_threshold) ||
nla_put_u32(skb, TCA_FQ_CE_THRESHOLD, (u32)ce_threshold) ||
nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log) ||
nla_put_u32(skb, TCA_FQ_TIMER_SLACK, q->timer_slack) ||
nla_put_u32(skb, TCA_FQ_HORIZON, (u32)horizon) ||
nla_put_u8(skb, TCA_FQ_HORIZON_DROP, q->horizon_drop))
goto nla_put_failure;
return nla_nest_end(skb, opts);
nla_put_failure:
return -1;
}
static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
struct fq_sched_data *q = qdisc_priv(sch);
struct tc_fq_qd_stats st;
sch_tree_lock(sch);
st.gc_flows = q->stat_gc_flows;
st.highprio_packets = q->stat_internal_packets;
st.tcp_retrans = 0;
st.throttled = q->stat_throttled;
st.flows_plimit = q->stat_flows_plimit;
st.pkts_too_long = q->stat_pkts_too_long;
st.allocation_errors = q->stat_allocation_errors;
st.time_next_delayed_flow = q->time_next_delayed_flow + q->timer_slack -
ktime_get_ns();
st.flows = q->flows;
st.inactive_flows = q->inactive_flows;
st.throttled_flows = q->throttled_flows;
st.unthrottle_latency_ns = min_t(unsigned long,
q->unthrottle_latency_ns, ~0U);
st.ce_mark = q->stat_ce_mark;
st.horizon_drops = q->stat_horizon_drops;
st.horizon_caps = q->stat_horizon_caps;
sch_tree_unlock(sch);
return gnet_stats_copy_app(d, &st, sizeof(st));
}
static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
.id = "fq",
.priv_size = sizeof(struct fq_sched_data),
.enqueue = fq_enqueue,
.dequeue = fq_dequeue,
.peek = qdisc_peek_dequeued,
.init = fq_init,
.reset = fq_reset,
.destroy = fq_destroy,
.change = fq_change,
.dump = fq_dump,
.dump_stats = fq_dump_stats,
.owner = THIS_MODULE,
};
static int __init fq_module_init(void)
{
int ret;
fq_flow_cachep = kmem_cache_create("fq_flow_cache",
sizeof(struct fq_flow),
0, 0, NULL);
if (!fq_flow_cachep)
return -ENOMEM;
ret = register_qdisc(&fq_qdisc_ops);
if (ret)
kmem_cache_destroy(fq_flow_cachep);
return ret;
}
static void __exit fq_module_exit(void)
{
unregister_qdisc(&fq_qdisc_ops);
kmem_cache_destroy(fq_flow_cachep);
}
module_init(fq_module_init)
module_exit(fq_module_exit)
MODULE_AUTHOR("Eric Dumazet");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Fair Queue Packet Scheduler");