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authorEric Dumazet <edumazet@google.com>2016-12-04 09:48:16 -0800
committerDavid S. Miller <davem@davemloft.net>2016-12-05 15:21:59 -0500
commit1c0d32fde5bdf1184bc274f864c09799278a1114 (patch)
tree47367d46dfc125e19294c3f5fa9a021520bd5660 /net/netfilter
parenta6e169312971219a34927e8fdece60046fafb8ba (diff)
net_sched: gen_estimator: complete rewrite of rate estimators
1) Old code was hard to maintain, due to complex lock chains. (We probably will be able to remove some kfree_rcu() in callers) 2) Using a single timer to update all estimators does not scale. 3) Code was buggy on 32bit kernel (WRITE_ONCE() on 64bit quantity is not supposed to work well) In this rewrite : - I removed the RB tree that had to be scanned in gen_estimator_active(). qdisc dumps should be much faster. - Each estimator has its own timer. - Estimations are maintained in net_rate_estimator structure, instead of dirtying the qdisc. Minor, but part of the simplification. - Reading the estimator uses RCU and a seqcount to provide proper support for 32bit kernels. - We reduce memory need when estimators are not used, since we store a pointer, instead of the bytes/packets counters. - xt_rateest_mt() no longer has to grab a spinlock. (In the future, xt_rateest_tg() could be switched to per cpu counters) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/xt_RATEEST.c4
-rw-r--r--net/netfilter/xt_rateest.c28
2 files changed, 15 insertions, 17 deletions
diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c
index dbd6c4a12b97..91a373a3f534 100644
--- a/net/netfilter/xt_RATEEST.c
+++ b/net/netfilter/xt_RATEEST.c
@@ -63,7 +63,7 @@ void xt_rateest_put(struct xt_rateest *est)
mutex_lock(&xt_rateest_mutex);
if (--est->refcnt == 0) {
hlist_del(&est->list);
- gen_kill_estimator(&est->bstats, &est->rstats);
+ gen_kill_estimator(&est->rate_est);
/*
* gen_estimator est_timer() might access est->lock or bstats,
* wait a RCU grace period before freeing 'est'
@@ -132,7 +132,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par)
cfg.est.interval = info->interval;
cfg.est.ewma_log = info->ewma_log;
- ret = gen_new_estimator(&est->bstats, NULL, &est->rstats,
+ ret = gen_new_estimator(&est->bstats, NULL, &est->rate_est,
&est->lock, NULL, &cfg.opt);
if (ret < 0)
goto err2;
diff --git a/net/netfilter/xt_rateest.c b/net/netfilter/xt_rateest.c
index 7720b036d76a..1db02f6fca54 100644
--- a/net/netfilter/xt_rateest.c
+++ b/net/netfilter/xt_rateest.c
@@ -18,35 +18,33 @@ static bool
xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
const struct xt_rateest_match_info *info = par->matchinfo;
- struct gnet_stats_rate_est64 *r;
+ struct gnet_stats_rate_est64 sample = {0};
u_int32_t bps1, bps2, pps1, pps2;
bool ret = true;
- spin_lock_bh(&info->est1->lock);
- r = &info->est1->rstats;
+ gen_estimator_read(&info->est1->rate_est, &sample);
+
if (info->flags & XT_RATEEST_MATCH_DELTA) {
- bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
- pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
+ bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
+ pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
} else {
- bps1 = r->bps;
- pps1 = r->pps;
+ bps1 = sample.bps;
+ pps1 = sample.pps;
}
- spin_unlock_bh(&info->est1->lock);
if (info->flags & XT_RATEEST_MATCH_ABS) {
bps2 = info->bps2;
pps2 = info->pps2;
} else {
- spin_lock_bh(&info->est2->lock);
- r = &info->est2->rstats;
+ gen_estimator_read(&info->est2->rate_est, &sample);
+
if (info->flags & XT_RATEEST_MATCH_DELTA) {
- bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
- pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
+ bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
+ pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
} else {
- bps2 = r->bps;
- pps2 = r->pps;
+ bps2 = sample.bps;
+ pps2 = sample.pps;
}
- spin_unlock_bh(&info->est2->lock);
}
switch (info->mode) {