1c0d32fde5
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>
27 lines
646 B
C
27 lines
646 B
C
#ifndef _XT_RATEEST_H
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#define _XT_RATEEST_H
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#include <net/gen_stats.h>
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struct xt_rateest {
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/* keep lock and bstats on same cache line to speedup xt_rateest_tg() */
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struct gnet_stats_basic_packed bstats;
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spinlock_t lock;
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/* following fields not accessed in hot path */
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unsigned int refcnt;
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struct hlist_node list;
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char name[IFNAMSIZ];
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struct gnet_estimator params;
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struct rcu_head rcu;
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/* keep this field far away to speedup xt_rateest_mt() */
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struct net_rate_estimator __rcu *rate_est;
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};
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struct xt_rateest *xt_rateest_lookup(const char *name);
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void xt_rateest_put(struct xt_rateest *est);
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#endif /* _XT_RATEEST_H */
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