From 0c45e76960ded9da56bd66e603a7f0cae215f87e Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 8 Jun 2015 14:42:40 +0200 Subject: [PATCH] netfilter: nft_counter: convert it to use per-cpu counters This patch converts the existing seqlock to per-cpu counters. Suggested-by: Eric Dumazet Suggested-by: Patrick McHardy Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_counter.c | 97 ++++++++++++++++++++++++++----------- 1 file changed, 69 insertions(+), 28 deletions(-) diff --git a/net/netfilter/nft_counter.c b/net/netfilter/nft_counter.c index 17591239229f..1067fb4c1ffa 100644 --- a/net/netfilter/nft_counter.c +++ b/net/netfilter/nft_counter.c @@ -18,39 +18,59 @@ #include struct nft_counter { - seqlock_t lock; u64 bytes; u64 packets; }; +struct nft_counter_percpu { + struct nft_counter counter; + struct u64_stats_sync syncp; +}; + +struct nft_counter_percpu_priv { + struct nft_counter_percpu __percpu *counter; +}; + static void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { - struct nft_counter *priv = nft_expr_priv(expr); - - write_seqlock_bh(&priv->lock); - priv->bytes += pkt->skb->len; - priv->packets++; - write_sequnlock_bh(&priv->lock); + struct nft_counter_percpu_priv *priv = nft_expr_priv(expr); + struct nft_counter_percpu *this_cpu; + + local_bh_disable(); + this_cpu = this_cpu_ptr(priv->counter); + u64_stats_update_begin(&this_cpu->syncp); + this_cpu->counter.bytes += pkt->skb->len; + this_cpu->counter.packets++; + u64_stats_update_end(&this_cpu->syncp); + local_bh_enable(); } static int nft_counter_dump(struct sk_buff *skb, const struct nft_expr *expr) { - struct nft_counter *priv = nft_expr_priv(expr); + struct nft_counter_percpu_priv *priv = nft_expr_priv(expr); + struct nft_counter_percpu *cpu_stats; + struct nft_counter total; + u64 bytes, packets; unsigned int seq; - u64 bytes; - u64 packets; - - do { - seq = read_seqbegin(&priv->lock); - bytes = priv->bytes; - packets = priv->packets; - } while (read_seqretry(&priv->lock, seq)); - - if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes))) - goto nla_put_failure; - if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets))) + int cpu; + + memset(&total, 0, sizeof(total)); + for_each_possible_cpu(cpu) { + cpu_stats = per_cpu_ptr(priv->counter, cpu); + do { + seq = u64_stats_fetch_begin_irq(&cpu_stats->syncp); + bytes = cpu_stats->counter.bytes; + packets = cpu_stats->counter.packets; + } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq)); + + total.packets += packets; + total.bytes += bytes; + } + + if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes)) || + nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets))) goto nla_put_failure; return 0; @@ -67,23 +87,44 @@ static int nft_counter_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) { - struct nft_counter *priv = nft_expr_priv(expr); + struct nft_counter_percpu_priv *priv = nft_expr_priv(expr); + struct nft_counter_percpu __percpu *cpu_stats; + struct nft_counter_percpu *this_cpu; + + cpu_stats = netdev_alloc_pcpu_stats(struct nft_counter_percpu); + if (cpu_stats == NULL) + return ENOMEM; + + preempt_disable(); + this_cpu = this_cpu_ptr(cpu_stats); + if (tb[NFTA_COUNTER_PACKETS]) { + this_cpu->counter.packets = + be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS])); + } + if (tb[NFTA_COUNTER_BYTES]) { + this_cpu->counter.bytes = + be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES])); + } + preempt_enable(); + priv->counter = cpu_stats; + return 0; +} - if (tb[NFTA_COUNTER_PACKETS]) - priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS])); - if (tb[NFTA_COUNTER_BYTES]) - priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES])); +static void nft_counter_destroy(const struct nft_ctx *ctx, + const struct nft_expr *expr) +{ + struct nft_counter_percpu_priv *priv = nft_expr_priv(expr); - seqlock_init(&priv->lock); - return 0; + free_percpu(priv->counter); } static struct nft_expr_type nft_counter_type; static const struct nft_expr_ops nft_counter_ops = { .type = &nft_counter_type, - .size = NFT_EXPR_SIZE(sizeof(struct nft_counter)), + .size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)), .eval = nft_counter_eval, .init = nft_counter_init, + .destroy = nft_counter_destroy, .dump = nft_counter_dump, }; -- 2.20.1