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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-11-13 01:24:04 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-11-14 05:12:26 (GMT) |
| commit | 2a24444f8f2bea694003e3eac5c2f8d9a386bdc5 (patch) | |
| tree | ef283db22c931c518ac6c0b8bca2e23dd62a7736 /include/net | |
| parent | 3d249d4ca7d0ed6629a135ea1ea21c72286c0d80 (diff) | |
| download | linux-2a24444f8f2bea694003e3eac5c2f8d9a386bdc5.tar.xz | |
ipv6: reduce percpu needs for icmpv6msg mibs
Reading /proc/net/snmp6 on a machine with a lot of cpus is very
expensive (can be ~88000 us).
This is because ICMPV6MSG MIB uses 4096 bytes per cpu, and folding
values for all possible cpus can read 16 Mbytes of memory (32MBytes on
non x86 arches)
ICMP messages are not considered as fast path on a typical server, and
eventually few cpus handle them anyway. We can afford an atomic
operation instead of using percpu data.
This saves 4096 bytes per cpu and per network namespace.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/ipv6.h | 15 | ||||
| -rw-r--r-- | include/net/netns/mib.h | 2 | ||||
| -rw-r--r-- | include/net/snmp.h | 2 |
3 files changed, 14 insertions, 5 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h index a366a8a..3f0258d 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -132,6 +132,15 @@ extern struct ctl_path net_ipv6_ctl_path[]; SNMP_INC_STATS##modifier((net)->mib.statname##_statistics, (field));\ }) +/* per device and per net counters are atomic_long_t */ +#define _DEVINC_ATOMIC_ATOMIC(net, statname, idev, field) \ +({ \ + struct inet6_dev *_idev = (idev); \ + if (likely(_idev != NULL)) \ + SNMP_INC_STATS_ATOMIC_LONG((_idev)->stats.statname##dev, (field)); \ + SNMP_INC_STATS_ATOMIC_LONG((net)->mib.statname##_statistics, (field));\ +}) + #define _DEVADD(net, statname, modifier, idev, field, val) \ ({ \ struct inet6_dev *_idev = (idev); \ @@ -168,11 +177,11 @@ extern struct ctl_path net_ipv6_ctl_path[]; _DEVINCATOMIC(net, icmpv6, _BH, idev, field) #define ICMP6MSGOUT_INC_STATS(net, idev, field) \ - _DEVINCATOMIC(net, icmpv6msg, , idev, field +256) + _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256) #define ICMP6MSGOUT_INC_STATS_BH(net, idev, field) \ - _DEVINCATOMIC(net, icmpv6msg, _BH, idev, field +256) + _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field +256) #define ICMP6MSGIN_INC_STATS_BH(net, idev, field) \ - _DEVINCATOMIC(net, icmpv6msg, _BH, idev, field) + _DEVINC_ATOMIC_ATOMIC(net, icmpv6msg, idev, field) struct ip6_ra_chain { struct ip6_ra_chain *next; diff --git a/include/net/netns/mib.h b/include/net/netns/mib.h index f360135..30f6728 100644 --- a/include/net/netns/mib.h +++ b/include/net/netns/mib.h @@ -18,7 +18,7 @@ struct netns_mib { DEFINE_SNMP_STAT(struct udp_mib, udplite_stats_in6); DEFINE_SNMP_STAT(struct ipstats_mib, ipv6_statistics); DEFINE_SNMP_STAT(struct icmpv6_mib, icmpv6_statistics); - DEFINE_SNMP_STAT(struct icmpv6msg_mib, icmpv6msg_statistics); + DEFINE_SNMP_STAT_ATOMIC(struct icmpv6msg_mib, icmpv6msg_statistics); #endif #ifdef CONFIG_XFRM_STATISTICS DEFINE_SNMP_STAT(struct linux_xfrm_mib, xfrm_statistics); diff --git a/include/net/snmp.h b/include/net/snmp.h index 0feafa6..2f65e16 100644 --- a/include/net/snmp.h +++ b/include/net/snmp.h @@ -84,7 +84,7 @@ struct icmpv6_mib_device { #define ICMP6MSG_MIB_MAX __ICMP6MSG_MIB_MAX /* per network ns counters */ struct icmpv6msg_mib { - unsigned long mibs[ICMP6MSG_MIB_MAX]; + atomic_long_t mibs[ICMP6MSG_MIB_MAX]; }; /* per device counters, (shared on all cpus) */ struct icmpv6msg_mib_device { |