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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 /include/net/netfilter/xt_rateest.h | |
parent | a6e169312971219a34927e8fdece60046fafb8ba (diff) | |
download | linux-stable-1c0d32fde5bdf1184bc274f864c09799278a1114.tar.gz linux-stable-1c0d32fde5bdf1184bc274f864c09799278a1114.tar.bz2 linux-stable-1c0d32fde5bdf1184bc274f864c09799278a1114.zip |
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/netfilter/xt_rateest.h')
-rw-r--r-- | include/net/netfilter/xt_rateest.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/include/net/netfilter/xt_rateest.h b/include/net/netfilter/xt_rateest.h index 79f45e19f31e..130e58361f99 100644 --- a/include/net/netfilter/xt_rateest.h +++ b/include/net/netfilter/xt_rateest.h @@ -1,19 +1,23 @@ #ifndef _XT_RATEEST_H #define _XT_RATEEST_H +#include <net/gen_stats.h> + struct xt_rateest { /* keep lock and bstats on same cache line to speedup xt_rateest_tg() */ struct gnet_stats_basic_packed bstats; spinlock_t lock; - /* keep rstats and lock on same cache line to speedup xt_rateest_mt() */ - struct gnet_stats_rate_est64 rstats; + /* following fields not accessed in hot path */ + unsigned int refcnt; struct hlist_node list; char name[IFNAMSIZ]; - unsigned int refcnt; struct gnet_estimator params; struct rcu_head rcu; + + /* keep this field far away to speedup xt_rateest_mt() */ + struct net_rate_estimator __rcu *rate_est; }; struct xt_rateest *xt_rateest_lookup(const char *name); |