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![Davide Caratti](/assets/img/avatar_default.png)
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/377
Fixes: afe4fd0624
("pkt_sched: fq: Fair Queue packet scheduler")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7b3a3c7e36d03068707a021760a194a8eb5ad41a.1682002300.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
1079 lines
27 KiB
C
1079 lines
27 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing)
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*
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* Copyright (C) 2013-2015 Eric Dumazet <edumazet@google.com>
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*
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* Meant to be mostly used for locally generated traffic :
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* Fast classification depends on skb->sk being set before reaching us.
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* If not, (router workload), we use rxhash as fallback, with 32 bits wide hash.
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* All packets belonging to a socket are considered as a 'flow'.
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*
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* Flows are dynamically allocated and stored in a hash table of RB trees
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* They are also part of one Round Robin 'queues' (new or old flows)
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*
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* Burst avoidance (aka pacing) capability :
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*
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* Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a
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* bunch of packets, and this packet scheduler adds delay between
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* packets to respect rate limitation.
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*
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* enqueue() :
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* - lookup one RB tree (out of 1024 or more) to find the flow.
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* If non existent flow, create it, add it to the tree.
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* Add skb to the per flow list of skb (fifo).
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* - Use a special fifo for high prio packets
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*
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* dequeue() : serves flows in Round Robin
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* Note : When a flow becomes empty, we do not immediately remove it from
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* rb trees, for performance reasons (its expected to send additional packets,
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* or SLAB cache will reuse socket for another flow)
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/jiffies.h>
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#include <linux/string.h>
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#include <linux/in.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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#include <linux/rbtree.h>
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#include <linux/hash.h>
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#include <linux/prefetch.h>
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#include <linux/vmalloc.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <net/sock.h>
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#include <net/tcp_states.h>
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#include <net/tcp.h>
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struct fq_skb_cb {
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u64 time_to_send;
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};
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static inline struct fq_skb_cb *fq_skb_cb(struct sk_buff *skb)
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{
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qdisc_cb_private_validate(skb, sizeof(struct fq_skb_cb));
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return (struct fq_skb_cb *)qdisc_skb_cb(skb)->data;
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}
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/*
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* Per flow structure, dynamically allocated.
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* If packets have monotically increasing time_to_send, they are placed in O(1)
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* in linear list (head,tail), otherwise are placed in a rbtree (t_root).
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*/
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struct fq_flow {
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/* First cache line : used in fq_gc(), fq_enqueue(), fq_dequeue() */
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struct rb_root t_root;
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struct sk_buff *head; /* list of skbs for this flow : first skb */
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union {
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struct sk_buff *tail; /* last skb in the list */
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unsigned long age; /* (jiffies | 1UL) when flow was emptied, for gc */
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};
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struct rb_node fq_node; /* anchor in fq_root[] trees */
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struct sock *sk;
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u32 socket_hash; /* sk_hash */
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int qlen; /* number of packets in flow queue */
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/* Second cache line, used in fq_dequeue() */
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int credit;
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/* 32bit hole on 64bit arches */
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struct fq_flow *next; /* next pointer in RR lists */
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struct rb_node rate_node; /* anchor in q->delayed tree */
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u64 time_next_packet;
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} ____cacheline_aligned_in_smp;
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struct fq_flow_head {
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struct fq_flow *first;
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struct fq_flow *last;
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};
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struct fq_sched_data {
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struct fq_flow_head new_flows;
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struct fq_flow_head old_flows;
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struct rb_root delayed; /* for rate limited flows */
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u64 time_next_delayed_flow;
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u64 ktime_cache; /* copy of last ktime_get_ns() */
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unsigned long unthrottle_latency_ns;
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struct fq_flow internal; /* for non classified or high prio packets */
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u32 quantum;
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u32 initial_quantum;
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u32 flow_refill_delay;
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u32 flow_plimit; /* max packets per flow */
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unsigned long flow_max_rate; /* optional max rate per flow */
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u64 ce_threshold;
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u64 horizon; /* horizon in ns */
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u32 orphan_mask; /* mask for orphaned skb */
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u32 low_rate_threshold;
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struct rb_root *fq_root;
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u8 rate_enable;
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u8 fq_trees_log;
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u8 horizon_drop;
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u32 flows;
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u32 inactive_flows;
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u32 throttled_flows;
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u64 stat_gc_flows;
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u64 stat_internal_packets;
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u64 stat_throttled;
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u64 stat_ce_mark;
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u64 stat_horizon_drops;
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u64 stat_horizon_caps;
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u64 stat_flows_plimit;
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u64 stat_pkts_too_long;
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u64 stat_allocation_errors;
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u32 timer_slack; /* hrtimer slack in ns */
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struct qdisc_watchdog watchdog;
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};
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/*
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* f->tail and f->age share the same location.
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* We can use the low order bit to differentiate if this location points
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* to a sk_buff or contains a jiffies value, if we force this value to be odd.
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* This assumes f->tail low order bit must be 0 since alignof(struct sk_buff) >= 2
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*/
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static void fq_flow_set_detached(struct fq_flow *f)
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{
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f->age = jiffies | 1UL;
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}
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static bool fq_flow_is_detached(const struct fq_flow *f)
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{
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return !!(f->age & 1UL);
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}
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/* special value to mark a throttled flow (not on old/new list) */
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static struct fq_flow throttled;
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static bool fq_flow_is_throttled(const struct fq_flow *f)
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{
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return f->next == &throttled;
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}
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static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
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{
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if (head->first)
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head->last->next = flow;
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else
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head->first = flow;
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head->last = flow;
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flow->next = NULL;
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}
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static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f)
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{
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rb_erase(&f->rate_node, &q->delayed);
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q->throttled_flows--;
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fq_flow_add_tail(&q->old_flows, f);
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}
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static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
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{
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struct rb_node **p = &q->delayed.rb_node, *parent = NULL;
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while (*p) {
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struct fq_flow *aux;
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parent = *p;
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aux = rb_entry(parent, struct fq_flow, rate_node);
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if (f->time_next_packet >= aux->time_next_packet)
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p = &parent->rb_right;
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else
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p = &parent->rb_left;
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}
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rb_link_node(&f->rate_node, parent, p);
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rb_insert_color(&f->rate_node, &q->delayed);
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q->throttled_flows++;
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q->stat_throttled++;
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f->next = &throttled;
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if (q->time_next_delayed_flow > f->time_next_packet)
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q->time_next_delayed_flow = f->time_next_packet;
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}
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static struct kmem_cache *fq_flow_cachep __read_mostly;
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/* limit number of collected flows per round */
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#define FQ_GC_MAX 8
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#define FQ_GC_AGE (3*HZ)
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static bool fq_gc_candidate(const struct fq_flow *f)
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{
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return fq_flow_is_detached(f) &&
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time_after(jiffies, f->age + FQ_GC_AGE);
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}
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static void fq_gc(struct fq_sched_data *q,
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struct rb_root *root,
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struct sock *sk)
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{
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struct rb_node **p, *parent;
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void *tofree[FQ_GC_MAX];
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struct fq_flow *f;
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int i, fcnt = 0;
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p = &root->rb_node;
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parent = NULL;
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while (*p) {
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parent = *p;
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f = rb_entry(parent, struct fq_flow, fq_node);
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if (f->sk == sk)
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break;
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if (fq_gc_candidate(f)) {
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tofree[fcnt++] = f;
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if (fcnt == FQ_GC_MAX)
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break;
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}
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if (f->sk > sk)
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p = &parent->rb_right;
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else
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p = &parent->rb_left;
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}
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if (!fcnt)
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return;
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for (i = fcnt; i > 0; ) {
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f = tofree[--i];
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rb_erase(&f->fq_node, root);
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}
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q->flows -= fcnt;
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q->inactive_flows -= fcnt;
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q->stat_gc_flows += fcnt;
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kmem_cache_free_bulk(fq_flow_cachep, fcnt, tofree);
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}
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static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
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{
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struct rb_node **p, *parent;
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struct sock *sk = skb->sk;
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struct rb_root *root;
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struct fq_flow *f;
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/* warning: no starvation prevention... */
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if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
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return &q->internal;
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/* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
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* or a listener (SYNCOOKIE mode)
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* 1) request sockets are not full blown,
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* they do not contain sk_pacing_rate
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* 2) They are not part of a 'flow' yet
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* 3) We do not want to rate limit them (eg SYNFLOOD attack),
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* especially if the listener set SO_MAX_PACING_RATE
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* 4) We pretend they are orphaned
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*/
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if (!sk || sk_listener(sk)) {
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unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
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/* By forcing low order bit to 1, we make sure to not
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* collide with a local flow (socket pointers are word aligned)
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*/
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sk = (struct sock *)((hash << 1) | 1UL);
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skb_orphan(skb);
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} else if (sk->sk_state == TCP_CLOSE) {
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unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
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/*
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* Sockets in TCP_CLOSE are non connected.
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* Typical use case is UDP sockets, they can send packets
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* with sendto() to many different destinations.
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* We probably could use a generic bit advertising
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* non connected sockets, instead of sk_state == TCP_CLOSE,
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* if we care enough.
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*/
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sk = (struct sock *)((hash << 1) | 1UL);
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}
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root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)];
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if (q->flows >= (2U << q->fq_trees_log) &&
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q->inactive_flows > q->flows/2)
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fq_gc(q, root, sk);
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p = &root->rb_node;
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parent = NULL;
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while (*p) {
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parent = *p;
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f = rb_entry(parent, struct fq_flow, fq_node);
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if (f->sk == sk) {
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/* socket might have been reallocated, so check
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* if its sk_hash is the same.
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* It not, we need to refill credit with
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* initial quantum
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*/
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if (unlikely(skb->sk == sk &&
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f->socket_hash != sk->sk_hash)) {
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f->credit = q->initial_quantum;
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f->socket_hash = sk->sk_hash;
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if (q->rate_enable)
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smp_store_release(&sk->sk_pacing_status,
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SK_PACING_FQ);
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if (fq_flow_is_throttled(f))
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fq_flow_unset_throttled(q, f);
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f->time_next_packet = 0ULL;
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}
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return f;
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}
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if (f->sk > sk)
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p = &parent->rb_right;
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else
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p = &parent->rb_left;
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}
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f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
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if (unlikely(!f)) {
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q->stat_allocation_errors++;
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return &q->internal;
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}
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/* f->t_root is already zeroed after kmem_cache_zalloc() */
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fq_flow_set_detached(f);
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f->sk = sk;
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if (skb->sk == sk) {
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f->socket_hash = sk->sk_hash;
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if (q->rate_enable)
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smp_store_release(&sk->sk_pacing_status,
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SK_PACING_FQ);
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}
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f->credit = q->initial_quantum;
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rb_link_node(&f->fq_node, parent, p);
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rb_insert_color(&f->fq_node, root);
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q->flows++;
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q->inactive_flows++;
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return f;
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}
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static struct sk_buff *fq_peek(struct fq_flow *flow)
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{
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struct sk_buff *skb = skb_rb_first(&flow->t_root);
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struct sk_buff *head = flow->head;
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if (!skb)
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return head;
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if (!head)
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return skb;
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if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send)
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return skb;
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return head;
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}
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static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow,
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struct sk_buff *skb)
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{
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if (skb == flow->head) {
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flow->head = skb->next;
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} else {
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rb_erase(&skb->rbnode, &flow->t_root);
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skb->dev = qdisc_dev(sch);
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}
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}
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/* Remove one skb from flow queue.
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* This skb must be the return value of prior fq_peek().
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*/
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static void fq_dequeue_skb(struct Qdisc *sch, struct fq_flow *flow,
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struct sk_buff *skb)
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{
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fq_erase_head(sch, flow, skb);
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skb_mark_not_on_list(skb);
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flow->qlen--;
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qdisc_qstats_backlog_dec(sch, skb);
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sch->q.qlen--;
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}
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static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
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{
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struct rb_node **p, *parent;
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struct sk_buff *head, *aux;
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head = flow->head;
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if (!head ||
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fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) {
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if (!head)
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flow->head = skb;
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else
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flow->tail->next = skb;
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flow->tail = skb;
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skb->next = NULL;
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return;
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}
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p = &flow->t_root.rb_node;
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parent = NULL;
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while (*p) {
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parent = *p;
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aux = rb_to_skb(parent);
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if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send)
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p = &parent->rb_right;
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else
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p = &parent->rb_left;
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}
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rb_link_node(&skb->rbnode, parent, p);
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rb_insert_color(&skb->rbnode, &flow->t_root);
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}
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static bool fq_packet_beyond_horizon(const struct sk_buff *skb,
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const struct fq_sched_data *q)
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{
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return unlikely((s64)skb->tstamp > (s64)(q->ktime_cache + q->horizon));
|
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}
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static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
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struct sk_buff **to_free)
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{
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struct fq_sched_data *q = qdisc_priv(sch);
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struct fq_flow *f;
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if (unlikely(sch->q.qlen >= sch->limit))
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return qdisc_drop(skb, sch, to_free);
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if (!skb->tstamp) {
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fq_skb_cb(skb)->time_to_send = q->ktime_cache = ktime_get_ns();
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} else {
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/* Check if packet timestamp is too far in the future.
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* Try first if our cached value, to avoid ktime_get_ns()
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* cost in most cases.
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*/
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if (fq_packet_beyond_horizon(skb, q)) {
|
|
/* Refresh our cache and check another time */
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q->ktime_cache = ktime_get_ns();
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if (fq_packet_beyond_horizon(skb, q)) {
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if (q->horizon_drop) {
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q->stat_horizon_drops++;
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return qdisc_drop(skb, sch, to_free);
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}
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q->stat_horizon_caps++;
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skb->tstamp = q->ktime_cache + q->horizon;
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}
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}
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fq_skb_cb(skb)->time_to_send = skb->tstamp;
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}
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|
|
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 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] = 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 },
|
|
};
|
|
|
|
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");
|