netfilter: nft_counter: convert it to use per-cpu counters

This patch converts the existing seqlock to per-cpu counters.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2015-06-08 14:42:40 +02:00
Родитель d92cff89a0
Коммит 0c45e76960
1 изменённых файлов: 65 добавлений и 24 удалений

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@ -18,39 +18,59 @@
#include <net/netfilter/nf_tables.h> #include <net/netfilter/nf_tables.h>
struct nft_counter { struct nft_counter {
seqlock_t lock;
u64 bytes; u64 bytes;
u64 packets; 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, static void nft_counter_eval(const struct nft_expr *expr,
struct nft_regs *regs, struct nft_regs *regs,
const struct nft_pktinfo *pkt) const struct nft_pktinfo *pkt)
{ {
struct nft_counter *priv = nft_expr_priv(expr); struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
struct nft_counter_percpu *this_cpu;
write_seqlock_bh(&priv->lock); local_bh_disable();
priv->bytes += pkt->skb->len; this_cpu = this_cpu_ptr(priv->counter);
priv->packets++; u64_stats_update_begin(&this_cpu->syncp);
write_sequnlock_bh(&priv->lock); 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) 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; unsigned int seq;
u64 bytes; int cpu;
u64 packets;
memset(&total, 0, sizeof(total));
for_each_possible_cpu(cpu) {
cpu_stats = per_cpu_ptr(priv->counter, cpu);
do { do {
seq = read_seqbegin(&priv->lock); seq = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
bytes = priv->bytes; bytes = cpu_stats->counter.bytes;
packets = priv->packets; packets = cpu_stats->counter.packets;
} while (read_seqretry(&priv->lock, seq)); } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, seq));
if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(bytes))) total.packets += packets;
goto nla_put_failure; total.bytes += bytes;
if (nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(packets))) }
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; goto nla_put_failure;
return 0; return 0;
@ -67,23 +87,44 @@ static int nft_counter_init(const struct nft_ctx *ctx,
const struct nft_expr *expr, const struct nft_expr *expr,
const struct nlattr * const tb[]) 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;
if (tb[NFTA_COUNTER_PACKETS]) cpu_stats = netdev_alloc_pcpu_stats(struct nft_counter_percpu);
priv->packets = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS])); if (cpu_stats == NULL)
if (tb[NFTA_COUNTER_BYTES]) return ENOMEM;
priv->bytes = be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES]));
seqlock_init(&priv->lock); 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; return 0;
} }
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);
free_percpu(priv->counter);
}
static struct nft_expr_type nft_counter_type; static struct nft_expr_type nft_counter_type;
static const struct nft_expr_ops nft_counter_ops = { static const struct nft_expr_ops nft_counter_ops = {
.type = &nft_counter_type, .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, .eval = nft_counter_eval,
.init = nft_counter_init, .init = nft_counter_init,
.destroy = nft_counter_destroy,
.dump = nft_counter_dump, .dump = nft_counter_dump,
}; };