Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/sched/gen_estimator.c Simple rate estimator. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 10 | * Eric Dumazet <edumazet@google.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * |
| 12 | * Changes: |
| 13 | * Jamal Hadi Salim - moved it to net/core and reshulfed |
| 14 | * names to make it usable in general net subsystem. |
| 15 | */ |
| 16 | |
Linus Torvalds | 7c0f6ba | 2016-12-24 11:46:01 -0800 | [diff] [blame] | 17 | #include <linux/uaccess.h> |
Jiri Slaby | 1977f03 | 2007-10-18 23:40:25 -0700 | [diff] [blame] | 18 | #include <linux/bitops.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/module.h> |
| 20 | #include <linux/types.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/jiffies.h> |
| 23 | #include <linux/string.h> |
| 24 | #include <linux/mm.h> |
| 25 | #include <linux/socket.h> |
| 26 | #include <linux/sockios.h> |
| 27 | #include <linux/in.h> |
| 28 | #include <linux/errno.h> |
| 29 | #include <linux/interrupt.h> |
| 30 | #include <linux/netdevice.h> |
| 31 | #include <linux/skbuff.h> |
| 32 | #include <linux/rtnetlink.h> |
| 33 | #include <linux/init.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 34 | #include <linux/slab.h> |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 35 | #include <linux/seqlock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <net/sock.h> |
| 37 | #include <net/gen_stats.h> |
| 38 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 39 | /* This code is NOT intended to be used for statistics collection, |
| 40 | * its purpose is to provide a base for statistical multiplexing |
| 41 | * for controlled load service. |
| 42 | * If you need only statistics, run a user level daemon which |
| 43 | * periodically reads byte counters. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | */ |
| 45 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 46 | struct net_rate_estimator { |
Eric Dumazet | c1a8f1f | 2009-08-16 09:36:49 +0000 | [diff] [blame] | 47 | struct gnet_stats_basic_packed *bstats; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | spinlock_t *stats_lock; |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 49 | seqcount_t *running; |
John Fastabend | 22e0f8b | 2014-09-28 11:52:56 -0700 | [diff] [blame] | 50 | struct gnet_stats_basic_cpu __percpu *cpu_bstats; |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 51 | u8 ewma_log; |
| 52 | u8 intvl_log; /* period : (250ms << intvl_log) */ |
| 53 | |
| 54 | seqcount_t seq; |
| 55 | u32 last_packets; |
| 56 | u64 last_bytes; |
| 57 | |
| 58 | u64 avpps; |
| 59 | u64 avbps; |
| 60 | |
| 61 | unsigned long next_jiffies; |
| 62 | struct timer_list timer; |
| 63 | struct rcu_head rcu; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | }; |
| 65 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 66 | static void est_fetch_counters(struct net_rate_estimator *e, |
| 67 | struct gnet_stats_basic_packed *b) |
| 68 | { |
| 69 | if (e->stats_lock) |
| 70 | spin_lock(e->stats_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 72 | __gnet_stats_copy_basic(e->running, b, e->cpu_bstats, e->bstats); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 74 | if (e->stats_lock) |
| 75 | spin_unlock(e->stats_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 77 | } |
Jarek Poplawski | 4db0acf3 | 2008-11-24 15:48:05 -0800 | [diff] [blame] | 78 | |
Kees Cook | e99e88a | 2017-10-16 14:43:17 -0700 | [diff] [blame] | 79 | static void est_timer(struct timer_list *t) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | { |
Kees Cook | e99e88a | 2017-10-16 14:43:17 -0700 | [diff] [blame] | 81 | struct net_rate_estimator *est = from_timer(est, t, timer); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 82 | struct gnet_stats_basic_packed b; |
| 83 | u64 rate, brate; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 85 | est_fetch_counters(est, &b); |
Eric Dumazet | ca558e1 | 2017-09-13 11:16:45 -0700 | [diff] [blame] | 86 | brate = (b.bytes - est->last_bytes) << (10 - est->ewma_log - est->intvl_log); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 87 | brate -= (est->avbps >> est->ewma_log); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | |
Eric Dumazet | ca558e1 | 2017-09-13 11:16:45 -0700 | [diff] [blame] | 89 | rate = (u64)(b.packets - est->last_packets) << (10 - est->ewma_log - est->intvl_log); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 90 | rate -= (est->avpps >> est->ewma_log); |
Ranko Zivojnovic | 0929c2d | 2007-07-16 18:28:32 -0700 | [diff] [blame] | 91 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 92 | write_seqcount_begin(&est->seq); |
| 93 | est->avbps += brate; |
| 94 | est->avpps += rate; |
| 95 | write_seqcount_end(&est->seq); |
John Fastabend | 22e0f8b | 2014-09-28 11:52:56 -0700 | [diff] [blame] | 96 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 97 | est->last_bytes = b.bytes; |
| 98 | est->last_packets = b.packets; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 100 | est->next_jiffies += ((HZ/4) << est->intvl_log); |
| 101 | |
| 102 | if (unlikely(time_after_eq(jiffies, est->next_jiffies))) { |
| 103 | /* Ouch... timer was delayed. */ |
| 104 | est->next_jiffies = jiffies + 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | } |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 106 | mod_timer(&est->timer, est->next_jiffies); |
Jarek Poplawski | 4db0acf3 | 2008-11-24 15:48:05 -0800 | [diff] [blame] | 107 | } |
| 108 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | /** |
| 110 | * gen_new_estimator - create a new rate estimator |
| 111 | * @bstats: basic statistics |
Luis de Bethencourt | e9fc2f0 | 2016-03-19 21:31:38 +0000 | [diff] [blame] | 112 | * @cpu_bstats: bstats per cpu |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | * @rate_est: rate estimator statistics |
| 114 | * @stats_lock: statistics lock |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 115 | * @running: qdisc running seqcount |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | * @opt: rate estimator configuration TLV |
| 117 | * |
| 118 | * Creates a new rate estimator with &bstats as source and &rate_est |
| 119 | * as destination. A new timer with the interval specified in the |
| 120 | * configuration TLV is created. Upon each interval, the latest statistics |
| 121 | * will be read from &bstats and the estimated rate will be stored in |
Masanari Iida | e793c0f | 2014-09-04 23:44:36 +0900 | [diff] [blame] | 122 | * &rate_est with the statistics lock grabbed during this period. |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 123 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | * Returns 0 on success or a negative error code. |
Ranko Zivojnovic | 0929c2d | 2007-07-16 18:28:32 -0700 | [diff] [blame] | 125 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | */ |
Eric Dumazet | c1a8f1f | 2009-08-16 09:36:49 +0000 | [diff] [blame] | 127 | int gen_new_estimator(struct gnet_stats_basic_packed *bstats, |
John Fastabend | 22e0f8b | 2014-09-28 11:52:56 -0700 | [diff] [blame] | 128 | struct gnet_stats_basic_cpu __percpu *cpu_bstats, |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 129 | struct net_rate_estimator __rcu **rate_est, |
Ranko Zivojnovic | 0929c2d | 2007-07-16 18:28:32 -0700 | [diff] [blame] | 130 | spinlock_t *stats_lock, |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 131 | seqcount_t *running, |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 132 | struct nlattr *opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | { |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 134 | struct gnet_estimator *parm = nla_data(opt); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 135 | struct net_rate_estimator *old, *est; |
| 136 | struct gnet_stats_basic_packed b; |
| 137 | int intvl_log; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
Patrick McHardy | 1e90474 | 2008-01-22 22:11:17 -0800 | [diff] [blame] | 139 | if (nla_len(opt) < sizeof(*parm)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | return -EINVAL; |
| 141 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 142 | /* allowed timer periods are : |
| 143 | * -2 : 250ms, -1 : 500ms, 0 : 1 sec |
| 144 | * 1 : 2 sec, 2 : 4 sec, 3 : 8 sec |
| 145 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | if (parm->interval < -2 || parm->interval > 3) |
| 147 | return -EINVAL; |
| 148 | |
Andrew Morton | 77d04bd | 2006-04-07 14:52:59 -0700 | [diff] [blame] | 149 | est = kzalloc(sizeof(*est), GFP_KERNEL); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 150 | if (!est) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | return -ENOBUFS; |
| 152 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 153 | seqcount_init(&est->seq); |
| 154 | intvl_log = parm->interval + 2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | est->bstats = bstats; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | est->stats_lock = stats_lock; |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 157 | est->running = running; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | est->ewma_log = parm->ewma_log; |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 159 | est->intvl_log = intvl_log; |
John Fastabend | 22e0f8b | 2014-09-28 11:52:56 -0700 | [diff] [blame] | 160 | est->cpu_bstats = cpu_bstats; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | |
Eric Dumazet | 40ca54e | 2018-01-27 10:58:43 -0800 | [diff] [blame] | 162 | if (stats_lock) |
| 163 | local_bh_disable(); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 164 | est_fetch_counters(est, &b); |
Eric Dumazet | 40ca54e | 2018-01-27 10:58:43 -0800 | [diff] [blame] | 165 | if (stats_lock) |
| 166 | local_bh_enable(); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 167 | est->last_bytes = b.bytes; |
| 168 | est->last_packets = b.packets; |
| 169 | old = rcu_dereference_protected(*rate_est, 1); |
| 170 | if (old) { |
| 171 | del_timer_sync(&old->timer); |
| 172 | est->avbps = old->avbps; |
| 173 | est->avpps = old->avpps; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | } |
Ranko Zivojnovic | 0929c2d | 2007-07-16 18:28:32 -0700 | [diff] [blame] | 175 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 176 | est->next_jiffies = jiffies + ((HZ/4) << intvl_log); |
Kees Cook | e99e88a | 2017-10-16 14:43:17 -0700 | [diff] [blame] | 177 | timer_setup(&est->timer, est_timer, 0); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 178 | mod_timer(&est->timer, est->next_jiffies); |
Jarek Poplawski | 4db0acf3 | 2008-11-24 15:48:05 -0800 | [diff] [blame] | 179 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 180 | rcu_assign_pointer(*rate_est, est); |
| 181 | if (old) |
| 182 | kfree_rcu(old, rcu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | return 0; |
| 184 | } |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 185 | EXPORT_SYMBOL(gen_new_estimator); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | |
| 187 | /** |
| 188 | * gen_kill_estimator - remove a rate estimator |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 189 | * @rate_est: rate estimator |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | * |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 191 | * Removes the rate estimator. |
Ranko Zivojnovic | 0929c2d | 2007-07-16 18:28:32 -0700 | [diff] [blame] | 192 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | */ |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 194 | void gen_kill_estimator(struct net_rate_estimator __rcu **rate_est) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | { |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 196 | struct net_rate_estimator *est; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 198 | est = xchg((__force struct net_rate_estimator **)rate_est, NULL); |
| 199 | if (est) { |
| 200 | del_timer_sync(&est->timer); |
| 201 | kfree_rcu(est, rcu); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | } |
| 203 | } |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 204 | EXPORT_SYMBOL(gen_kill_estimator); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | |
| 206 | /** |
Jarek Poplawski | 9675016 | 2008-01-21 02:36:02 -0800 | [diff] [blame] | 207 | * gen_replace_estimator - replace rate estimator configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | * @bstats: basic statistics |
Luis de Bethencourt | e9fc2f0 | 2016-03-19 21:31:38 +0000 | [diff] [blame] | 209 | * @cpu_bstats: bstats per cpu |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | * @rate_est: rate estimator statistics |
| 211 | * @stats_lock: statistics lock |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 212 | * @running: qdisc running seqcount (might be NULL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | * @opt: rate estimator configuration TLV |
| 214 | * |
| 215 | * Replaces the configuration of a rate estimator by calling |
| 216 | * gen_kill_estimator() and gen_new_estimator(). |
YOSHIFUJI Hideaki | 4ec93ed | 2007-02-09 23:24:36 +0900 | [diff] [blame] | 217 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | * Returns 0 on success or a negative error code. |
| 219 | */ |
Eric Dumazet | c1a8f1f | 2009-08-16 09:36:49 +0000 | [diff] [blame] | 220 | int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, |
John Fastabend | 22e0f8b | 2014-09-28 11:52:56 -0700 | [diff] [blame] | 221 | struct gnet_stats_basic_cpu __percpu *cpu_bstats, |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 222 | struct net_rate_estimator __rcu **rate_est, |
Eric Dumazet | edb09eb | 2016-06-06 09:37:16 -0700 | [diff] [blame] | 223 | spinlock_t *stats_lock, |
| 224 | seqcount_t *running, struct nlattr *opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | { |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 226 | return gen_new_estimator(bstats, cpu_bstats, rate_est, |
| 227 | stats_lock, running, opt); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | EXPORT_SYMBOL(gen_replace_estimator); |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 230 | |
| 231 | /** |
| 232 | * gen_estimator_active - test if estimator is currently in use |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 233 | * @rate_est: rate estimator |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 234 | * |
Jarek Poplawski | 244e6c2 | 2008-11-26 15:24:32 -0800 | [diff] [blame] | 235 | * Returns true if estimator is active, and false if not. |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 236 | */ |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 237 | bool gen_estimator_active(struct net_rate_estimator __rcu **rate_est) |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 238 | { |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 239 | return !!rcu_access_pointer(*rate_est); |
Stephen Hemminger | c1b5687 | 2008-11-25 21:14:06 -0800 | [diff] [blame] | 240 | } |
| 241 | EXPORT_SYMBOL(gen_estimator_active); |
Eric Dumazet | 1c0d32f | 2016-12-04 09:48:16 -0800 | [diff] [blame] | 242 | |
| 243 | bool gen_estimator_read(struct net_rate_estimator __rcu **rate_est, |
| 244 | struct gnet_stats_rate_est64 *sample) |
| 245 | { |
| 246 | struct net_rate_estimator *est; |
| 247 | unsigned seq; |
| 248 | |
| 249 | rcu_read_lock(); |
| 250 | est = rcu_dereference(*rate_est); |
| 251 | if (!est) { |
| 252 | rcu_read_unlock(); |
| 253 | return false; |
| 254 | } |
| 255 | |
| 256 | do { |
| 257 | seq = read_seqcount_begin(&est->seq); |
| 258 | sample->bps = est->avbps >> 8; |
| 259 | sample->pps = est->avpps >> 8; |
| 260 | } while (read_seqcount_retry(&est->seq, seq)); |
| 261 | |
| 262 | rcu_read_unlock(); |
| 263 | return true; |
| 264 | } |
| 265 | EXPORT_SYMBOL(gen_estimator_read); |