Change how synchronization is done on the iptables counters. Use seqcount wrapper instead of depending on reader/writer lock. Signed-off-by: Stephen Hemminger --- include/linux/netfilter/x_tables.h | 14 +++----------- net/ipv4/netfilter/arp_tables.c | 4 ++-- net/ipv4/netfilter/ip_tables.c | 4 ++-- net/ipv6/netfilter/ip6_tables.c | 4 ++-- net/netfilter/x_tables.c | 28 ++++++++++++++++++++++++++++ 5 files changed, 37 insertions(+), 17 deletions(-) 4 --- a/net/ipv4/netfilter/arp_tables.c 2009-01-29 11:08:38.735069921 -0800 +++ b/net/ipv4/netfilter/arp_tables.c 2009-01-29 11:09:20.720069979 -0800 @@ -736,9 +736,9 @@ static inline struct xt_counters *alloc_ return ERR_PTR(-ENOMEM); /* First, sum counters... */ - write_lock_bh(&table->lock); + local_bh_disable(); get_counters(private, counters); - write_unlock_bh(&table->lock); + local_bh_enable(); return counters; } --- a/net/ipv4/netfilter/ip_tables.c 2009-01-29 11:08:38.723069778 -0800 +++ b/net/ipv4/netfilter/ip_tables.c 2009-01-29 11:09:20.720069979 -0800 @@ -947,9 +947,9 @@ static struct xt_counters * alloc_counte return ERR_PTR(-ENOMEM); /* First, sum counters... */ - write_lock_bh(&table->lock); + local_bh_disable(); get_counters(private, counters); - write_unlock_bh(&table->lock); + local_bh_enable(); return counters; } --- a/net/ipv6/netfilter/ip6_tables.c 2009-01-29 11:08:38.763071181 -0800 +++ b/net/ipv6/netfilter/ip6_tables.c 2009-01-29 11:09:20.724069866 -0800 @@ -976,9 +976,9 @@ static struct xt_counters *alloc_counter return ERR_PTR(-ENOMEM); /* First, sum counters... */ - write_lock_bh(&table->lock); + local_bh_disable(); get_counters(private, counters); - write_unlock_bh(&table->lock); + local_bh_enable(); return counters; } --- a/net/netfilter/x_tables.c 2009-01-29 11:08:38.747070716 -0800 +++ b/net/netfilter/x_tables.c 2009-01-29 11:10:03.595571234 -0800 @@ -577,6 +577,34 @@ int xt_compat_target_to_user(struct xt_e EXPORT_SYMBOL_GPL(xt_compat_target_to_user); #endif +static DEFINE_PER_CPU(seqcount_t, xt_counter_sequence); + +void xt_fetch_counter(struct xt_counters *v, int cpu, + const struct xt_counters *c) +{ + seqcount_t *seq = &per_cpu(xt_counter_sequence, cpu); + unsigned start; + + do { + start = read_seqcount_begin(seq); + *v = *c; + } while (read_seqcount_retry(seq, start)); +} +EXPORT_SYMBOL_GPL(xt_fetch_counter); + +void xt_incr_counter(struct xt_counters *c, unsigned b, unsigned p) +{ + seqcount_t *seq = &__get_cpu_var(xt_counter_sequence); + + write_seqcount_begin(seq); + c->pcnt += p; + c->bcnt += b; + write_seqcount_end(seq); + +} +EXPORT_SYMBOL_GPL(xt_incr_counter); + + struct xt_table_info *xt_alloc_table_info(unsigned int size) { struct xt_table_info *newinfo; --- a/include/linux/netfilter/x_tables.h 2009-01-29 11:08:38.779071484 -0800 +++ b/include/linux/netfilter/x_tables.h 2009-01-29 11:09:20.724069866 -0800 @@ -112,17 +112,9 @@ struct xt_counters u_int64_t pcnt, bcnt; /* Packet and byte counters */ }; -static inline void xt_fetch_counter(struct xt_counters *v, int cpu, - const struct xt_counters *c) -{ - *v = *c; -} - -static inline void xt_incr_counter(struct xt_counters *c, unsigned b, unsigned p) -{ - c->pcnt += p; - c->bcnt += b; -} +extern void xt_fetch_counter(struct xt_counters *v, int cpu, + const struct xt_counters *c); +extern void xt_incr_counter(struct xt_counters *c, unsigned b, unsigned p); /* The argument to IPT_SO_ADD_COUNTERS. */ -- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html