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Release 4.14 net/core/gen_estimator.c

Directory: net/core
 * net/sched/gen_estimator.c    Simple rate estimator.
 *              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.
 * Authors:     Alexey Kuznetsov, <>
 *              Eric Dumazet <>
 * Changes:
 *              Jamal Hadi Salim - moved it to net/core and reshulfed
 *              names to make it usable in general net subsystem.

#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/seqlock.h>
#include <net/sock.h>
#include <net/gen_stats.h>

/* This code is NOT intended to be used for statistics collection,
 * its purpose is to provide a base for statistical multiplexing
 * for controlled load service.
 * If you need only statistics, run a user level daemon which
 * periodically reads byte counters.

struct net_rate_estimator {
struct gnet_stats_basic_packed	*bstats;
spinlock_t		*stats_lock;
seqcount_t		*running;
struct gnet_stats_basic_cpu __percpu *cpu_bstats;
u8			ewma_log;
u8			intvl_log; /* period : (250ms << intvl_log) */

seqcount_t		seq;
u32			last_packets;
u64			last_bytes;

u64			avpps;
u64			avbps;

unsigned long           next_jiffies;
struct timer_list       timer;
struct rcu_head		rcu;

static void est_fetch_counters(struct net_rate_estimator *e, struct gnet_stats_basic_packed *b) { if (e->stats_lock) spin_lock(e->stats_lock); __gnet_stats_copy_basic(e->running, b, e->cpu_bstats, e->bstats); if (e->stats_lock) spin_unlock(e->stats_lock); }


Eric Dumazet2949.15%250.00%
David S. Miller1932.20%125.00%
John Fastabend1118.64%125.00%

static void est_timer(unsigned long arg) { struct net_rate_estimator *est = (struct net_rate_estimator *)arg; struct gnet_stats_basic_packed b; u64 rate, brate; est_fetch_counters(est, &b); brate = (b.bytes - est->last_bytes) << (10 - est->ewma_log - est->intvl_log); brate -= (est->avbps >> est->ewma_log); rate = (u64)(b.packets - est->last_packets) << (10 - est->ewma_log - est->intvl_log); rate -= (est->avpps >> est->ewma_log); write_seqcount_begin(&est->seq); est->avbps += brate; est->avpps += rate; write_seqcount_end(&est->seq); est->last_bytes = b.bytes; est->last_packets = b.packets; est->next_jiffies += ((HZ/4) << est->intvl_log); if (unlikely(time_after_eq(jiffies, est->next_jiffies))) { /* Ouch... timer was delayed. */ est->next_jiffies = jiffies + 1; } mod_timer(&est->timer, est->next_jiffies); }


Eric Dumazet14367.77%550.00%
David S. Miller4219.91%110.00%
Jarek Poplawski178.06%220.00%
John Fastabend62.84%110.00%
Ranko Zivojnovic31.42%110.00%

/** * gen_new_estimator - create a new rate estimator * @bstats: basic statistics * @cpu_bstats: bstats per cpu * @rate_est: rate estimator statistics * @stats_lock: statistics lock * @running: qdisc running seqcount * @opt: rate estimator configuration TLV * * Creates a new rate estimator with &bstats as source and &rate_est * as destination. A new timer with the interval specified in the * configuration TLV is created. Upon each interval, the latest statistics * will be read from &bstats and the estimated rate will be stored in * &rate_est with the statistics lock grabbed during this period. * * Returns 0 on success or a negative error code. * */
int gen_new_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **rate_est, spinlock_t *stats_lock, seqcount_t *running, struct nlattr *opt) { struct gnet_estimator *parm = nla_data(opt); struct net_rate_estimator *old, *est; struct gnet_stats_basic_packed b; int intvl_log; if (nla_len(opt) < sizeof(*parm)) return -EINVAL; /* allowed timer periods are : * -2 : 250ms, -1 : 500ms, 0 : 1 sec * 1 : 2 sec, 2 : 4 sec, 3 : 8 sec */ if (parm->interval < -2 || parm->interval > 3) return -EINVAL; est = kzalloc(sizeof(*est), GFP_KERNEL); if (!est) return -ENOBUFS; seqcount_init(&est->seq); intvl_log = parm->interval + 2; est->bstats = bstats; est->stats_lock = stats_lock; est->running = running; est->ewma_log = parm->ewma_log; est->intvl_log = intvl_log; est->cpu_bstats = cpu_bstats; est_fetch_counters(est, &b); est->last_bytes = b.bytes; est->last_packets = b.packets; old = rcu_dereference_protected(*rate_est, 1); if (old) { del_timer_sync(&old->timer); est->avbps = old->avbps; est->avpps = old->avpps; } est->next_jiffies = jiffies + ((HZ/4) << intvl_log); setup_timer(&est->timer, est_timer, (unsigned long)est); mod_timer(&est->timer, est->next_jiffies); rcu_assign_pointer(*rate_est, est); if (old) kfree_rcu(old, rcu); return 0; }


David S. Miller15049.34%18.33%
Eric Dumazet11939.14%650.00%
John Fastabend175.59%18.33%
Ranko Zivojnovic103.29%18.33%
Jarek Poplawski41.32%18.33%
Patrick McHardy30.99%18.33%
Andrew Morton10.33%18.33%

EXPORT_SYMBOL(gen_new_estimator); /** * gen_kill_estimator - remove a rate estimator * @rate_est: rate estimator * * Removes the rate estimator. * */
void gen_kill_estimator(struct net_rate_estimator __rcu **rate_est) { struct net_rate_estimator *est; est = xchg((__force struct net_rate_estimator **)rate_est, NULL); if (est) { del_timer_sync(&est->timer); kfree_rcu(est, rcu); } }


Eric Dumazet2342.59%116.67%
David S. Miller2240.74%233.33%
Ranko Zivojnovic59.26%116.67%
Jarek Poplawski35.56%116.67%
Lai Jiangshan11.85%116.67%

EXPORT_SYMBOL(gen_kill_estimator); /** * gen_replace_estimator - replace rate estimator configuration * @bstats: basic statistics * @cpu_bstats: bstats per cpu * @rate_est: rate estimator statistics * @stats_lock: statistics lock * @running: qdisc running seqcount (might be NULL) * @opt: rate estimator configuration TLV * * Replaces the configuration of a rate estimator by calling * gen_kill_estimator() and gen_new_estimator(). * * Returns 0 on success or a negative error code. */
int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct net_rate_estimator __rcu **rate_est, spinlock_t *stats_lock, seqcount_t *running, struct nlattr *opt) { return gen_new_estimator(bstats, cpu_bstats, rate_est, stats_lock, running, opt); }


Thomas Graf3261.54%114.29%
Eric Dumazet1019.23%342.86%
John Fastabend815.38%114.29%
Jarek Poplawski11.92%114.29%
Patrick McHardy11.92%114.29%

EXPORT_SYMBOL(gen_replace_estimator); /** * gen_estimator_active - test if estimator is currently in use * @rate_est: rate estimator * * Returns true if estimator is active, and false if not. */
bool gen_estimator_active(struct net_rate_estimator __rcu **rate_est) { return !!rcu_access_pointer(*rate_est); }


Eric Dumazet1676.19%133.33%
Stephen Hemminger314.29%133.33%
Jarek Poplawski29.52%133.33%

bool gen_estimator_read(struct net_rate_estimator __rcu **rate_est, struct gnet_stats_rate_est64 *sample) { struct net_rate_estimator *est; unsigned seq; rcu_read_lock(); est = rcu_dereference(*rate_est); if (!est) { rcu_read_unlock(); return false; } do { seq = read_seqcount_begin(&est->seq); sample->bps = est->avbps >> 8; sample->pps = est->avpps >> 8; } while (read_seqcount_retry(&est->seq, seq)); rcu_read_unlock(); return true; }


Eric Dumazet9089.11%350.00%
Stephen Hemminger76.93%116.67%
Jarek Poplawski32.97%116.67%
David S. Miller10.99%116.67%


Overall Contributors

Eric Dumazet47950.21%1038.46%
David S. Miller31633.12%27.69%
John Fastabend424.40%13.85%
Thomas Graf363.77%13.85%
Jarek Poplawski323.35%415.38%
Stephen Hemminger212.20%13.85%
Ranko Zivojnovic181.89%13.85%
Patrick McHardy40.42%13.85%
Tejun Heo20.21%13.85%
Andrew Morton10.10%13.85%
Jiri Slaby10.10%13.85%
Lai Jiangshan10.10%13.85%
Linus Torvalds10.10%13.85%
Directory: net/core
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