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-rw-r--r--net/sched/sch_fq.c767
1 files changed, 605 insertions, 162 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index 1a662f2bb7bb..6e5f2f4f2415 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -1,12 +1,8 @@
+// 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>
- *
- * 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) 2013-2023 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.
@@ -54,21 +50,45 @@
#include <net/tcp_states.h>
#include <net/tcp.h>
+struct fq_skb_cb {
+ u64 time_to_send;
+ u8 band;
+};
+
+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
+ * 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 when flow was emptied, for gc */
+ unsigned long age; /* (jiffies | 1UL) when flow was emptied, for gc */
+ };
+ union {
+ struct rb_node fq_node; /* anchor in fq_root[] trees */
+ /* Following field is only used for q->internal,
+ * because q->internal is not hashed in fq_root[]
+ */
+ u64 stat_fastpath_packets;
};
- 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 */
int credit;
- u32 socket_hash; /* sk_hash */
- struct fq_flow *next; /* next pointer in RR lists, or &detached */
+ int band;
+ struct fq_flow *next; /* next pointer in RR lists */
struct rb_node rate_node; /* anchor in q->delayed tree */
u64 time_next_packet;
@@ -79,63 +99,109 @@ struct fq_flow_head {
struct fq_flow *last;
};
-struct fq_sched_data {
+struct fq_perband_flows {
struct fq_flow_head new_flows;
-
struct fq_flow_head old_flows;
+ int credit;
+ int quantum; /* based on band nr : 576KB, 192KB, 64KB */
+};
- struct rb_root delayed; /* for rate limited flows */
- u64 time_next_delayed_flow;
- unsigned long unthrottle_latency_ns;
+#define FQ_PRIO2BAND_CRUMB_SIZE ((TC_PRIO_MAX + 1) >> 2)
+
+struct fq_sched_data {
+/* Read mostly cache line */
- struct fq_flow internal; /* for non classified or high prio packets */
+ u64 offload_horizon;
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;
+ u8 prio2band[FQ_PRIO2BAND_CRUMB_SIZE];
+ u32 timer_slack; /* hrtimer slack in ns */
+
+/* Read/Write fields. */
+
+ unsigned int band_nr; /* band being serviced in fq_dequeue() */
+
+ struct fq_perband_flows band_flows[FQ_BANDS];
+
+ struct fq_flow internal; /* fastpath queue. */
+ struct rb_root delayed; /* for rate limited flows */
+ u64 time_next_delayed_flow;
+ unsigned long unthrottle_latency_ns;
+ u32 band_pkt_count[FQ_BANDS];
u32 flows;
- u32 inactive_flows;
+ u32 inactive_flows; /* Flows with no packet to send. */
u32 throttled_flows;
- u64 stat_gc_flows;
- u64 stat_internal_packets;
u64 stat_throttled;
+ struct qdisc_watchdog watchdog;
+ u64 stat_gc_flows;
+
+/* Seldom used fields. */
+
+ u64 stat_band_drops[FQ_BANDS];
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;
- struct qdisc_watchdog watchdog;
};
-/* special value to mark a detached flow (not on old/new list) */
-static struct fq_flow detached, throttled;
+/* return the i-th 2-bit value ("crumb") */
+static u8 fq_prio2band(const u8 *prio2band, unsigned int prio)
+{
+ return (READ_ONCE(prio2band[prio / 4]) >> (2 * (prio & 0x3))) & 0x3;
+}
+/*
+ * 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->next = &detached;
- f->age = jiffies;
+ f->age = jiffies | 1UL;
}
static bool fq_flow_is_detached(const struct fq_flow *f)
{
- return f->next == &detached;
+ 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)
+enum new_flow {
+ NEW_FLOW,
+ OLD_FLOW
+};
+
+static void fq_flow_add_tail(struct fq_sched_data *q, struct fq_flow *flow,
+ enum new_flow list_sel)
{
+ struct fq_perband_flows *pband = &q->band_flows[flow->band];
+ struct fq_flow_head *head = (list_sel == NEW_FLOW) ?
+ &pband->new_flows :
+ &pband->old_flows;
+
if (head->first)
head->last->next = flow;
else
@@ -148,7 +214,7 @@ 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);
+ fq_flow_add_tail(q, f, OLD_FLOW);
}
static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
@@ -193,9 +259,10 @@ static void fq_gc(struct fq_sched_data *q,
struct rb_root *root,
struct sock *sk)
{
- struct fq_flow *f, *tofree[FQ_GC_MAX];
struct rb_node **p, *parent;
- int fcnt = 0;
+ void *tofree[FQ_GC_MAX];
+ struct fq_flow *f;
+ int i, fcnt = 0;
p = &root->rb_node;
parent = NULL;
@@ -218,28 +285,81 @@ static void fq_gc(struct fq_sched_data *q,
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;
- while (fcnt) {
- struct fq_flow *f = tofree[--fcnt];
- rb_erase(&f->fq_node, root);
- kmem_cache_free(fq_flow_cachep, f);
+ kmem_cache_free_bulk(fq_flow_cachep, fcnt, tofree);
+}
+
+/* Fast path can be used if :
+ * 1) Packet tstamp is in the past, or within the pacing offload horizon.
+ * 2) FQ qlen == 0 OR
+ * (no flow is currently eligible for transmit,
+ * AND fast path queue has less than 8 packets)
+ * 3) No SO_MAX_PACING_RATE on the socket (if any).
+ * 4) No @maxrate attribute on this qdisc,
+ *
+ * FQ can not use generic TCQ_F_CAN_BYPASS infrastructure.
+ */
+static bool fq_fastpath_check(const struct Qdisc *sch, struct sk_buff *skb,
+ u64 now)
+{
+ const struct fq_sched_data *q = qdisc_priv(sch);
+ const struct sock *sk;
+
+ if (fq_skb_cb(skb)->time_to_send > now + q->offload_horizon)
+ return false;
+
+ if (sch->q.qlen != 0) {
+ /* Even if some packets are stored in this qdisc,
+ * we can still enable fast path if all of them are
+ * scheduled in the future (ie no flows are eligible)
+ * or in the fast path queue.
+ */
+ if (q->flows != q->inactive_flows + q->throttled_flows)
+ return false;
+
+ /* Do not allow fast path queue to explode, we want Fair Queue mode
+ * under pressure.
+ */
+ if (q->internal.qlen >= 8)
+ return false;
+
+ /* Ordering invariants fall apart if some delayed flows
+ * are ready but we haven't serviced them, yet.
+ */
+ if (q->time_next_delayed_flow <= now + q->offload_horizon)
+ return false;
}
+
+ sk = skb->sk;
+ if (sk && sk_fullsock(sk) && !sk_is_tcp(sk) &&
+ sk->sk_max_pacing_rate != ~0UL)
+ return false;
+
+ if (q->flow_max_rate != ~0UL)
+ return false;
+
+ return true;
}
-static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
+static struct fq_flow *fq_classify(struct Qdisc *sch, struct sk_buff *skb,
+ u64 now)
{
+ struct fq_sched_data *q = qdisc_priv(sch);
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,
@@ -248,8 +368,9 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
* 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
+ * TCP can also associate TIME_WAIT sockets with RST or ACK packets.
*/
- if (!sk || sk_listener(sk)) {
+ if (!sk || sk_listener_or_tw(sk)) {
unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
/* By forcing low order bit to 1, we make sure to not
@@ -257,13 +378,31 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
*/
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);
+ }
+
+ if (fq_fastpath_check(sch, skb, now)) {
+ q->internal.stat_fastpath_packets++;
+ if (skb->sk == sk && q->rate_enable &&
+ READ_ONCE(sk->sk_pacing_status) != SK_PACING_FQ)
+ smp_store_release(&sk->sk_pacing_status,
+ SK_PACING_FQ);
+ return &q->internal;
}
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);
+ fq_gc(q, root, sk);
p = &root->rb_node;
parent = NULL;
@@ -277,10 +416,13 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
* It not, we need to refill credit with
* initial quantum
*/
- if (unlikely(skb->sk &&
+ 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;
@@ -298,10 +440,16 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
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)
+ 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);
@@ -312,92 +460,171 @@ static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
return f;
}
-
-/* remove one skb from head of flow queue */
-static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
+static struct sk_buff *fq_peek(struct fq_flow *flow)
{
- struct sk_buff *skb = flow->head;
+ struct sk_buff *skb = skb_rb_first(&flow->t_root);
+ struct sk_buff *head = flow->head;
- if (skb) {
- flow->head = skb->next;
- skb_mark_not_on_list(skb);
- flow->qlen--;
- qdisc_qstats_backlog_dec(sch, skb);
- sch->q.qlen--;
+ 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) {
+ struct sk_buff *next = skb->next;
+
+ prefetch(next);
+ flow->head = next;
+ } else {
+ rb_erase(&skb->rbnode, &flow->t_root);
+ skb->dev = qdisc_dev(sch);
}
- return skb;
+}
+
+/* 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);
+ qdisc_qstats_backlog_dec(sch, skb);
+ sch->q.qlen--;
+ qdisc_bstats_update(sch, skb);
}
static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
{
- struct sk_buff *head = flow->head;
+ struct rb_node **p, *parent;
+ struct sk_buff *head, *aux;
- skb->next = NULL;
- if (!head)
- flow->head = skb;
- else
- flow->tail->next = skb;
+ 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);
+}
- flow->tail = skb;
+static bool fq_packet_beyond_horizon(const struct sk_buff *skb,
+ const struct fq_sched_data *q, u64 now)
+{
+ return unlikely((s64)skb->tstamp > (s64)(now + q->horizon));
}
+#define FQDR(reason) SKB_DROP_REASON_FQ_##reason
+
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;
+ u64 now;
+ u8 band;
- if (unlikely(sch->q.qlen >= sch->limit))
- return qdisc_drop(skb, sch, to_free);
+ band = fq_prio2band(q->prio2band, skb->priority & TC_PRIO_MAX);
+ if (unlikely(q->band_pkt_count[band] >= sch->limit)) {
+ q->stat_band_drops[band]++;
+ return qdisc_drop_reason(skb, sch, to_free,
+ FQDR(BAND_LIMIT));
+ }
- 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);
+ now = ktime_get_ns();
+ if (!skb->tstamp) {
+ fq_skb_cb(skb)->time_to_send = now;
+ } else {
+ /* Check if packet timestamp is too far in the future. */
+ if (fq_packet_beyond_horizon(skb, q, now)) {
+ if (q->horizon_drop) {
+ q->stat_horizon_drops++;
+ return qdisc_drop_reason(skb, sch, to_free,
+ FQDR(HORIZON_LIMIT));
+ }
+ q->stat_horizon_caps++;
+ skb->tstamp = now + q->horizon;
+ }
+ fq_skb_cb(skb)->time_to_send = skb->tstamp;
}
- f->qlen++;
- qdisc_qstats_backlog_inc(sch, skb);
- if (fq_flow_is_detached(f)) {
- struct sock *sk = skb->sk;
-
- 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);
- if (sk && q->rate_enable) {
- if (unlikely(smp_load_acquire(&sk->sk_pacing_status) !=
- SK_PACING_FQ))
- smp_store_release(&sk->sk_pacing_status,
- SK_PACING_FQ);
+ f = fq_classify(sch, skb, now);
+
+ if (f != &q->internal) {
+ if (unlikely(f->qlen >= q->flow_plimit)) {
+ q->stat_flows_plimit++;
+ return qdisc_drop_reason(skb, sch, to_free,
+ FQDR(FLOW_LIMIT));
+ }
+
+ if (fq_flow_is_detached(f)) {
+ fq_flow_add_tail(q, f, NEW_FLOW);
+ if (time_after(jiffies, f->age + q->flow_refill_delay))
+ f->credit = max_t(u32, f->credit, q->quantum);
}
- q->inactive_flows--;
+
+ f->band = band;
+ q->band_pkt_count[band]++;
+ fq_skb_cb(skb)->band = band;
+ if (f->qlen == 0)
+ q->inactive_flows--;
}
+ f->qlen++;
/* Note: this overwrites f->age */
flow_queue_add(f, skb);
- if (unlikely(f == &q->internal)) {
- q->stat_internal_packets++;
- }
+ qdisc_qstats_backlog_inc(sch, skb);
sch->q.qlen++;
return NET_XMIT_SUCCESS;
}
+#undef FQDR
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)
+ if (q->time_next_delayed_flow > now + q->offload_horizon)
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;
+ if ((long)sample > 0) {
+ q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3;
+ q->unthrottle_latency_ns += sample >> 3;
+ }
+ now += q->offload_horizon;
q->time_next_delayed_flow = ~0ULL;
while ((p = rb_first(&q->delayed)) != NULL) {
@@ -411,78 +638,104 @@ static void fq_check_throttled(struct fq_sched_data *q, u64 now)
}
}
+static struct fq_flow_head *fq_pband_head_select(struct fq_perband_flows *pband)
+{
+ if (pband->credit <= 0)
+ return NULL;
+
+ if (pband->new_flows.first)
+ return &pband->new_flows;
+
+ return pband->old_flows.first ? &pband->old_flows : NULL;
+}
+
static struct sk_buff *fq_dequeue(struct Qdisc *sch)
{
struct fq_sched_data *q = qdisc_priv(sch);
+ struct fq_perband_flows *pband;
struct fq_flow_head *head;
struct sk_buff *skb;
struct fq_flow *f;
unsigned long rate;
+ int retry;
u32 plen;
u64 now;
if (!sch->q.qlen)
return NULL;
- skb = fq_dequeue_head(sch, &q->internal);
- if (skb)
+ skb = fq_peek(&q->internal);
+ if (unlikely(skb)) {
+ q->internal.qlen--;
+ fq_dequeue_skb(sch, &q->internal, skb);
goto out;
+ }
now = ktime_get_ns();
fq_check_throttled(q, now);
+ retry = 0;
+ pband = &q->band_flows[q->band_nr];
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_ns(&q->watchdog,
- q->time_next_delayed_flow);
- return NULL;
+ head = fq_pband_head_select(pband);
+ if (!head) {
+ while (++retry <= FQ_BANDS) {
+ if (++q->band_nr == FQ_BANDS)
+ q->band_nr = 0;
+ pband = &q->band_flows[q->band_nr];
+ pband->credit = min(pband->credit + pband->quantum,
+ pband->quantum);
+ if (pband->credit > 0)
+ goto begin;
+ retry = 0;
}
+ 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;
-
+ retry = 0;
if (f->credit <= 0) {
f->credit += q->quantum;
head->first = f->next;
- fq_flow_add_tail(&q->old_flows, f);
+ fq_flow_add_tail(q, f, OLD_FLOW);
goto begin;
}
- skb = f->head;
+ skb = fq_peek(f);
if (skb) {
- u64 time_next_packet = max_t(u64, ktime_to_ns(skb->tstamp),
+ u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send,
f->time_next_packet);
- if (now < time_next_packet) {
+ if (now + q->offload_horizon < time_next_packet) {
head->first = f->next;
f->time_next_packet = time_next_packet;
fq_flow_set_throttled(q, f);
goto begin;
}
- if (time_next_packet &&
- (s64)(now - time_next_packet - q->ce_threshold) > 0) {
+ prefetch(&skb->end);
+ fq_dequeue_skb(sch, f, skb);
+ if ((s64)(now - time_next_packet - q->ce_threshold) > 0) {
INET_ECN_set_ce(skb);
q->stat_ce_mark++;
}
- }
-
- skb = fq_dequeue_head(sch, f);
- if (!skb) {
+ if (--f->qlen == 0)
+ q->inactive_flows++;
+ q->band_pkt_count[fq_skb_cb(skb)->band]--;
+ } 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);
+ if (head == &pband->new_flows) {
+ fq_flow_add_tail(q, f, OLD_FLOW);
} else {
fq_flow_set_detached(f);
- q->inactive_flows++;
}
goto begin;
}
- prefetch(&skb->end);
plen = qdisc_pkt_len(skb);
f->credit -= plen;
+ pband->credit -= plen;
if (!q->rate_enable)
goto out;
@@ -495,7 +748,7 @@ begin:
*/
if (!skb->tstamp) {
if (skb->sk)
- rate = min(skb->sk->sk_pacing_rate, rate);
+ rate = min(READ_ONCE(skb->sk->sk_pacing_rate), rate);
if (rate <= q->low_rate_threshold) {
f->credit = 0;
@@ -527,12 +780,20 @@ begin:
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;
@@ -565,8 +826,10 @@ static void fq_reset(struct Qdisc *sch)
kmem_cache_free(fq_flow_cachep, f);
}
}
- q->new_flows.first = NULL;
- q->old_flows.first = NULL;
+ for (idx = 0; idx < FQ_BANDS; idx++) {
+ q->band_flows[idx].new_flows.first = NULL;
+ q->band_flows[idx].old_flows.first = NULL;
+ }
q->delayed = RB_ROOT;
q->flows = 0;
q->inactive_flows = 0;
@@ -649,7 +912,7 @@ static int fq_resize(struct Qdisc *sch, u32 log)
fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
q->fq_root = array;
- q->fq_trees_log = log;
+ WRITE_ONCE(q->fq_trees_log, log);
sch_tree_unlock(sch);
@@ -658,33 +921,109 @@ static int fq_resize(struct Qdisc *sch, u32 log)
return 0;
}
+static const struct netlink_range_validation iq_range = {
+ .max = INT_MAX,
+};
+
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_INITIAL_QUANTUM] = NLA_POLICY_FULL_RANGE(NLA_U32, &iq_range),
[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 },
+ [TCA_FQ_PRIOMAP] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_prio_qopt)),
+ [TCA_FQ_WEIGHTS] = NLA_POLICY_EXACT_LEN(FQ_BANDS * sizeof(s32)),
+ [TCA_FQ_OFFLOAD_HORIZON] = { .type = NLA_U32 },
};
+/* compress a u8 array with all elems <= 3 to an array of 2-bit fields */
+static void fq_prio2band_compress_crumb(const u8 *in, u8 *out)
+{
+ const int num_elems = TC_PRIO_MAX + 1;
+ u8 tmp[FQ_PRIO2BAND_CRUMB_SIZE];
+ int i;
+
+ memset(tmp, 0, sizeof(tmp));
+ for (i = 0; i < num_elems; i++)
+ tmp[i / 4] |= in[i] << (2 * (i & 0x3));
+
+ for (i = 0; i < FQ_PRIO2BAND_CRUMB_SIZE; i++)
+ WRITE_ONCE(out[i], tmp[i]);
+}
+
+static void fq_prio2band_decompress_crumb(const u8 *in, u8 *out)
+{
+ const int num_elems = TC_PRIO_MAX + 1;
+ int i;
+
+ for (i = 0; i < num_elems; i++)
+ out[i] = fq_prio2band(in, i);
+}
+
+static int fq_load_weights(struct fq_sched_data *q,
+ const struct nlattr *attr,
+ struct netlink_ext_ack *extack)
+{
+ s32 *weights = nla_data(attr);
+ int i;
+
+ for (i = 0; i < FQ_BANDS; i++) {
+ if (weights[i] < FQ_MIN_WEIGHT) {
+ NL_SET_ERR_MSG_FMT_MOD(extack, "Weight %d less that minimum allowed %d",
+ weights[i], FQ_MIN_WEIGHT);
+ return -EINVAL;
+ }
+ }
+ for (i = 0; i < FQ_BANDS; i++)
+ WRITE_ONCE(q->band_flows[i].quantum, weights[i]);
+ return 0;
+}
+
+static int fq_load_priomap(struct fq_sched_data *q,
+ const struct nlattr *attr,
+ struct netlink_ext_ack *extack)
+{
+ const struct tc_prio_qopt *map = nla_data(attr);
+ int i;
+
+ if (map->bands != FQ_BANDS) {
+ NL_SET_ERR_MSG_MOD(extack, "FQ only supports 3 bands");
+ return -EINVAL;
+ }
+ for (i = 0; i < TC_PRIO_MAX + 1; i++) {
+ if (map->priomap[i] >= FQ_BANDS) {
+ NL_SET_ERR_MSG_FMT_MOD(extack, "FQ priomap field %d maps to a too high band %d",
+ i, map->priomap[i]);
+ return -EINVAL;
+ }
+ }
+ fq_prio2band_compress_crumb(map->priomap, q->prio2band);
+ return 0;
+}
+
static int fq_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
+ unsigned int dropped_pkts = 0, dropped_bytes = 0;
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;
+ int err;
- if (!opt)
- return -EINVAL;
-
- err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy, NULL);
+ err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy,
+ NULL);
if (err < 0)
return err;
@@ -701,22 +1040,27 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt,
err = -EINVAL;
}
if (tb[TCA_FQ_PLIMIT])
- sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
+ WRITE_ONCE(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]);
+ WRITE_ONCE(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)
- q->quantum = quantum;
- else
+ if (quantum > 0 && quantum <= (1 << 20)) {
+ WRITE_ONCE(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]);
+ WRITE_ONCE(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",
@@ -725,17 +1069,19 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt,
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;
+ WRITE_ONCE(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]);
+ WRITE_ONCE(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;
+ WRITE_ONCE(q->rate_enable,
+ enable);
else
err = -EINVAL;
}
@@ -743,31 +1089,67 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt,
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);
+ WRITE_ONCE(q->flow_refill_delay,
+ usecs_to_jiffies(usecs_delay));
}
+ if (!err && tb[TCA_FQ_PRIOMAP])
+ err = fq_load_priomap(q, tb[TCA_FQ_PRIOMAP], extack);
+
+ if (!err && tb[TCA_FQ_WEIGHTS])
+ err = fq_load_weights(q, tb[TCA_FQ_WEIGHTS], extack);
+
if (tb[TCA_FQ_ORPHAN_MASK])
- q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]);
+ WRITE_ONCE(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]);
+ WRITE_ONCE(q->ce_threshold,
+ (u64)NSEC_PER_USEC *
+ nla_get_u32(tb[TCA_FQ_CE_THRESHOLD]));
+
+ if (tb[TCA_FQ_TIMER_SLACK])
+ WRITE_ONCE(q->timer_slack,
+ nla_get_u32(tb[TCA_FQ_TIMER_SLACK]));
+
+ if (tb[TCA_FQ_HORIZON])
+ WRITE_ONCE(q->horizon,
+ (u64)NSEC_PER_USEC *
+ nla_get_u32(tb[TCA_FQ_HORIZON]));
+
+ if (tb[TCA_FQ_HORIZON_DROP])
+ WRITE_ONCE(q->horizon_drop,
+ nla_get_u8(tb[TCA_FQ_HORIZON_DROP]));
+
+ if (tb[TCA_FQ_OFFLOAD_HORIZON]) {
+ u64 offload_horizon = (u64)NSEC_PER_USEC *
+ nla_get_u32(tb[TCA_FQ_OFFLOAD_HORIZON]);
+ if (offload_horizon <= qdisc_dev(sch)->max_pacing_offload_horizon) {
+ WRITE_ONCE(q->offload_horizon, offload_horizon);
+ } else {
+ NL_SET_ERR_MSG_MOD(extack, "invalid offload_horizon");
+ err = -EINVAL;
+ }
+ }
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);
+ struct sk_buff *skb = qdisc_dequeue_internal(sch, false);
if (!skb)
break;
- drop_len += qdisc_pkt_len(skb);
+
+ dropped_pkts++;
+ dropped_bytes += qdisc_pkt_len(skb);
rtnl_kfree_skbs(skb, skb);
- drop_count++;
}
- qdisc_tree_reduce_backlog(sch, drop_count, drop_len);
+ qdisc_tree_reduce_backlog(sch, dropped_pkts, dropped_bytes);
sch_tree_unlock(sch);
return err;
@@ -786,7 +1168,7 @@ 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;
+ int i, err;
sch->limit = 10000;
q->flow_plimit = 100;
@@ -796,17 +1178,28 @@ static int fq_init(struct Qdisc *sch, struct nlattr *opt,
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;
+ for (i = 0; i < FQ_BANDS; i++) {
+ q->band_flows[i].new_flows.first = NULL;
+ q->band_flows[i].old_flows.first = NULL;
+ }
+ q->band_flows[0].quantum = 9 << 16;
+ q->band_flows[1].quantum = 3 << 16;
+ q->band_flows[2].quantum = 1 << 16;
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;
+ fq_prio2band_compress_crumb(sch_default_prio2band, q->prio2band);
qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC);
if (opt)
@@ -820,31 +1213,68 @@ static int fq_init(struct Qdisc *sch, struct nlattr *opt,
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;
+ struct tc_prio_qopt prio = {
+ .bands = FQ_BANDS,
+ };
struct nlattr *opts;
+ u64 offload_horizon;
+ u64 ce_threshold;
+ s32 weights[3];
+ u64 horizon;
- opts = nla_nest_start(skb, TCA_OPTIONS);
+ opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
/* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */
+ ce_threshold = READ_ONCE(q->ce_threshold);
do_div(ce_threshold, 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) ||
+ horizon = READ_ONCE(q->horizon);
+ do_div(horizon, NSEC_PER_USEC);
+
+ offload_horizon = READ_ONCE(q->offload_horizon);
+ do_div(offload_horizon, NSEC_PER_USEC);
+
+ if (nla_put_u32(skb, TCA_FQ_PLIMIT,
+ READ_ONCE(sch->limit)) ||
+ nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT,
+ READ_ONCE(q->flow_plimit)) ||
+ nla_put_u32(skb, TCA_FQ_QUANTUM,
+ READ_ONCE(q->quantum)) ||
+ nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM,
+ READ_ONCE(q->initial_quantum)) ||
+ nla_put_u32(skb, TCA_FQ_RATE_ENABLE,
+ READ_ONCE(q->rate_enable)) ||
nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE,
- min_t(unsigned long, q->flow_max_rate, ~0U)) ||
+ min_t(unsigned long,
+ READ_ONCE(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) ||
+ jiffies_to_usecs(READ_ONCE(q->flow_refill_delay))) ||
+ nla_put_u32(skb, TCA_FQ_ORPHAN_MASK,
+ READ_ONCE(q->orphan_mask)) ||
nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD,
- q->low_rate_threshold) ||
+ READ_ONCE(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_BUCKETS_LOG,
+ READ_ONCE(q->fq_trees_log)) ||
+ nla_put_u32(skb, TCA_FQ_TIMER_SLACK,
+ READ_ONCE(q->timer_slack)) ||
+ nla_put_u32(skb, TCA_FQ_HORIZON, (u32)horizon) ||
+ nla_put_u32(skb, TCA_FQ_OFFLOAD_HORIZON, (u32)offload_horizon) ||
+ nla_put_u8(skb, TCA_FQ_HORIZON_DROP,
+ READ_ONCE(q->horizon_drop)))
+ goto nla_put_failure;
+
+ fq_prio2band_decompress_crumb(q->prio2band, prio.priomap);
+ if (nla_put(skb, TCA_FQ_PRIOMAP, sizeof(prio), &prio))
+ goto nla_put_failure;
+
+ weights[0] = READ_ONCE(q->band_flows[0].quantum);
+ weights[1] = READ_ONCE(q->band_flows[1].quantum);
+ weights[2] = READ_ONCE(q->band_flows[2].quantum);
+ if (nla_put(skb, TCA_FQ_WEIGHTS, sizeof(weights), &weights))
goto nla_put_failure;
return nla_nest_end(skb, opts);
@@ -857,23 +1287,34 @@ 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;
+ int i;
+
+ st.pad = 0;
sch_tree_lock(sch);
st.gc_flows = q->stat_gc_flows;
- st.highprio_packets = q->stat_internal_packets;
+ st.highprio_packets = 0;
+ st.fastpath_packets = q->internal.stat_fastpath_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 - ktime_get_ns();
+ 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;
+ for (i = 0; i < FQ_BANDS; i++) {
+ st.band_drops[i] = q->stat_band_drops[i];
+ st.band_pkt_count[i] = q->band_pkt_count[i];
+ }
sch_tree_unlock(sch);
return gnet_stats_copy_app(d, &st, sizeof(st));
@@ -894,6 +1335,7 @@ static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
.dump_stats = fq_dump_stats,
.owner = THIS_MODULE,
};
+MODULE_ALIAS_NET_SCH("fq");
static int __init fq_module_init(void)
{
@@ -901,7 +1343,7 @@ static int __init fq_module_init(void)
fq_flow_cachep = kmem_cache_create("fq_flow_cache",
sizeof(struct fq_flow),
- 0, 0, NULL);
+ 0, SLAB_HWCACHE_ALIGN, NULL);
if (!fq_flow_cachep)
return -ENOMEM;
@@ -921,3 +1363,4 @@ module_init(fq_module_init)
module_exit(fq_module_exit)
MODULE_AUTHOR("Eric Dumazet");
MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Fair Queue Packet Scheduler");