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| author | Eric Dumazet <edumazet@google.com> | 2016-12-04 09:48:16 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-12-05 15:21:59 -0500 |
| commit | 1c0d32fde5bdf1184bc274f864c09799278a1114 (patch) | |
| tree | 47367d46dfc125e19294c3f5fa9a021520bd5660 /net/sched/act_police.c | |
| parent | a6e169312971219a34927e8fdece60046fafb8ba (diff) | |
| download | linux-1c0d32fde5bdf1184bc274f864c09799278a1114.tar.gz | |
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/sched/act_police.c')
| -rw-r--r-- | net/sched/act_police.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/net/sched/act_police.c b/net/sched/act_police.c index c990b73a6c85..0ba91d1ce994 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -142,8 +142,7 @@ static int tcf_act_police_init(struct net *net, struct nlattr *nla, goto failure_unlock; } else if (tb[TCA_POLICE_AVRATE] && (ret == ACT_P_CREATED || - !gen_estimator_active(&police->tcf_bstats, - &police->tcf_rate_est))) { + !gen_estimator_active(&police->tcf_rate_est))) { err = -EINVAL; goto failure_unlock; } @@ -216,13 +215,17 @@ static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a, bstats_update(&police->tcf_bstats, skb); tcf_lastuse_update(&police->tcf_tm); - if (police->tcfp_ewma_rate && - police->tcf_rate_est.bps >= police->tcfp_ewma_rate) { - police->tcf_qstats.overlimits++; - if (police->tcf_action == TC_ACT_SHOT) - police->tcf_qstats.drops++; - spin_unlock(&police->tcf_lock); - return police->tcf_action; + if (police->tcfp_ewma_rate) { + struct gnet_stats_rate_est64 sample; + + if (!gen_estimator_read(&police->tcf_rate_est, &sample) || + sample.bps >= police->tcfp_ewma_rate) { + police->tcf_qstats.overlimits++; + if (police->tcf_action == TC_ACT_SHOT) + police->tcf_qstats.drops++; + spin_unlock(&police->tcf_lock); + return police->tcf_action; + } } if (qdisc_pkt_len(skb) <= police->tcfp_mtu) { |