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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 /include/net/gen_stats.h
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 'include/net/gen_stats.h')
-rw-r--r--include/net/gen_stats.h17
1 files changed, 9 insertions, 8 deletions
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