From 1c0d32fde5bdf1184bc274f864c09799278a1114 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 4 Dec 2016 09:48:16 -0800 Subject: 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 Signed-off-by: David S. Miller --- net/netfilter/xt_rateest.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'net/netfilter/xt_rateest.c') 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) { -- cgit v1.2.3