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 --- include/net/gen_stats.h | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'include/net/gen_stats.h') diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h index 231e121cc7d9..8b7aa370e7a4 100644 --- a/include/net/gen_stats.h +++ b/include/net/gen_stats.h @@ -11,6 +11,8 @@ struct gnet_stats_basic_cpu { struct u64_stats_sync syncp; }; +struct net_rate_estimator; + struct gnet_dump { spinlock_t * lock; struct sk_buff * skb; @@ -42,8 +44,7 @@ void __gnet_stats_copy_basic(const seqcount_t *running, struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b); int gnet_stats_copy_rate_est(struct gnet_dump *d, - const struct gnet_stats_basic_packed *b, - struct gnet_stats_rate_est64 *r); + struct net_rate_estimator __rcu **ptr); int gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue __percpu *cpu_q, struct gnet_stats_queue *q, __u32 qlen); @@ -53,16 +54,16 @@ int gnet_stats_finish_copy(struct gnet_dump *d); int gen_new_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu_bstats, - struct gnet_stats_rate_est64 *rate_est, + struct net_rate_estimator __rcu **rate_est, spinlock_t *stats_lock, seqcount_t *running, struct nlattr *opt); -void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, - struct gnet_stats_rate_est64 *rate_est); +void gen_kill_estimator(struct net_rate_estimator __rcu **ptr); int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_basic_cpu __percpu *cpu_bstats, - struct gnet_stats_rate_est64 *rate_est, + struct net_rate_estimator __rcu **ptr, spinlock_t *stats_lock, seqcount_t *running, struct nlattr *opt); -bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats, - const struct gnet_stats_rate_est64 *rate_est); +bool gen_estimator_active(struct net_rate_estimator __rcu **ptr); +bool gen_estimator_read(struct net_rate_estimator __rcu **ptr, + struct gnet_stats_rate_est64 *sample); #endif -- cgit v1.2.3-59-g8ed1b