From 2cb4bbd75bdf9d423b9f6c629f81eb66ee312fac Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sat, 11 Mar 2017 14:08:09 +0800 Subject: netfilter: limit: use per-rule spinlock to improve the scalability The limit token is independent between each rules, so there's no need to use a global spinlock. Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_limit.c | 10 +++++----- net/netfilter/xt_limit.c | 11 ++++++----- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/net/netfilter/nft_limit.c b/net/netfilter/nft_limit.c index c6baf412236d..18dd57a52651 100644 --- a/net/netfilter/nft_limit.c +++ b/net/netfilter/nft_limit.c @@ -17,9 +17,8 @@ #include #include -static DEFINE_SPINLOCK(limit_lock); - struct nft_limit { + spinlock_t lock; u64 last; u64 tokens; u64 tokens_max; @@ -34,7 +33,7 @@ static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) u64 now, tokens; s64 delta; - spin_lock_bh(&limit_lock); + spin_lock_bh(&limit->lock); now = ktime_get_ns(); tokens = limit->tokens + now - limit->last; if (tokens > limit->tokens_max) @@ -44,11 +43,11 @@ static inline bool nft_limit_eval(struct nft_limit *limit, u64 cost) delta = tokens - cost; if (delta >= 0) { limit->tokens = delta; - spin_unlock_bh(&limit_lock); + spin_unlock_bh(&limit->lock); return limit->invert; } limit->tokens = tokens; - spin_unlock_bh(&limit_lock); + spin_unlock_bh(&limit->lock); return !limit->invert; } @@ -86,6 +85,7 @@ static int nft_limit_init(struct nft_limit *limit, limit->invert = true; } limit->last = ktime_get_ns(); + spin_lock_init(&limit->lock); return 0; } diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c index dab962df1787..d27b5f1ea619 100644 --- a/net/netfilter/xt_limit.c +++ b/net/netfilter/xt_limit.c @@ -18,6 +18,7 @@ #include struct xt_limit_priv { + spinlock_t lock; unsigned long prev; uint32_t credit; }; @@ -32,8 +33,6 @@ MODULE_ALIAS("ip6t_limit"); * see net/sched/sch_tbf.c in the linux source tree */ -static DEFINE_SPINLOCK(limit_lock); - /* Rusty: This is my (non-mathematically-inclined) understanding of this algorithm. The `average rate' in jiffies becomes your initial amount of credit `credit' and the most credit you can ever have @@ -72,7 +71,7 @@ limit_mt(const struct sk_buff *skb, struct xt_action_param *par) struct xt_limit_priv *priv = r->master; unsigned long now = jiffies; - spin_lock_bh(&limit_lock); + spin_lock_bh(&priv->lock); priv->credit += (now - xchg(&priv->prev, now)) * CREDITS_PER_JIFFY; if (priv->credit > r->credit_cap) priv->credit = r->credit_cap; @@ -80,11 +79,11 @@ limit_mt(const struct sk_buff *skb, struct xt_action_param *par) if (priv->credit >= r->cost) { /* We're not limited. */ priv->credit -= r->cost; - spin_unlock_bh(&limit_lock); + spin_unlock_bh(&priv->lock); return true; } - spin_unlock_bh(&limit_lock); + spin_unlock_bh(&priv->lock); return false; } @@ -126,6 +125,8 @@ static int limit_mt_check(const struct xt_mtchk_param *par) r->credit_cap = priv->credit; /* Credits full. */ r->cost = user2credits(r->avg); } + spin_lock_init(&priv->lock); + return 0; } -- cgit v1.2.3