This patch converts the existing seqlock to per-cpu counters.
Suggested-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Suggested-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
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 1759123..1067fb4 100644
--- a/net/netfilter/nft_counter.c
+++ b/net/netfilter/nft_counter.c
@@ -18,39 +18,59 @@
#include <net/netfilter/nf_tables.h>
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,
};
--
1.7.10.4
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