linux/net/ipv6
Raghavendra K T a3a773726c net: Optimize snmp stat aggregation by walking all the percpu data at once
Docker container creation linearly increased from around 1.6 sec to 7.5 sec
(at 1000 containers) and perf data showed 50% ovehead in snmp_fold_field.

reason: currently __snmp6_fill_stats64 calls snmp_fold_field that walks
through per cpu data of an item (iteratively for around 36 items).

idea: This patch tries to aggregate the statistics by going through
all the items of each cpu sequentially which is reducing cache
misses.

Docker creation got faster by more than 2x after the patch.

Result:
                       Before           After
Docker creation time   6.836s           3.25s
cache miss             2.7%             1.41%

perf before:
    50.73%  docker           [kernel.kallsyms]       [k] snmp_fold_field
     9.07%  swapper          [kernel.kallsyms]       [k] snooze_loop
     3.49%  docker           [kernel.kallsyms]       [k] veth_stats_one
     2.85%  swapper          [kernel.kallsyms]       [k] _raw_spin_lock

perf after:
    10.57%  docker           docker                [.] scanblock
     8.37%  swapper          [kernel.kallsyms]     [k] snooze_loop
     6.91%  docker           [kernel.kallsyms]     [k] snmp_get_cpu_field
     6.67%  docker           [kernel.kallsyms]     [k] veth_stats_one

changes/ideas suggested:
Using buffer in stack (Eric), Usage of memset (David), Using memcpy in
place of unaligned_put (Joe).

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-30 21:48:58 -07:00
..
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2015-08-28 16:29:59 -07:00
addrconf_core.c ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument 2015-07-31 15:21:30 -07:00
addrconf.c net: Optimize snmp stat aggregation by walking all the percpu data at once 2015-08-30 21:48:58 -07:00
addrlabel.c netlink: implement nla_put_in_addr and nla_put_in6_addr 2015-03-31 13:58:35 -04:00
af_inet6.c ipv6: Disable flowlabel state ranges by default 2015-07-31 17:07:11 -07:00
ah6.c ah6: fix error return code 2015-08-25 13:37:31 -07:00
anycast.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
datagram.c net: Set sk_txhash from a random number 2015-07-29 22:44:04 -07:00
esp6.c esp6: Switch to new AEAD interface 2015-05-28 11:23:20 +08:00
exthdrs_core.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
exthdrs_offload.c ipv6: Fix exthdrs offload registration. 2014-03-06 16:35:55 -05:00
exthdrs.c ipv6: use flag instead of u16 for hop in inet6_skb_parm 2015-07-09 15:06:59 -07:00
fib6_rules.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
icmp.c ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument 2015-07-31 15:21:30 -07:00
ila.c ila: Precompute checksum difference for translations 2015-08-24 10:34:40 -07:00
inet6_connection_sock.c net: convert syn_wait_lock to a spinlock 2015-03-23 16:52:26 -04:00
inet6_hashtables.c inet: inet_twsk_deschedule factorization 2015-07-09 15:12:20 -07:00
ip6_checksum.c udp: Generic functions to set checksum 2014-06-04 22:46:38 -07:00
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-21 11:44:04 -07:00
ip6_flowlabel.c ipv6: Flow label state ranges 2015-05-03 21:58:01 -04:00
ip6_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-27 21:45:31 -07:00
ip6_icmp.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
ip6_input.c ipv6: fix crash over flow-based vxlan device 2015-07-26 20:54:56 -07:00
ip6_offload.c Revert "sit: Add gro callbacks to sit_offload" 2015-07-20 16:52:28 -07:00
ip6_offload.h ipv6: Pull IPv6 GSO registration out of the module 2012-11-15 17:39:24 -05:00
ip6_output.c ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel 2015-07-31 17:07:11 -07:00
ip6_tunnel.c ipv6: Implement different admin modes for automatic flow labels 2015-07-31 17:07:11 -07:00
ip6_udp_tunnel.c vxlan: do not receive IPv4 packets on IPv6 socket 2015-08-29 13:07:54 -07:00
ip6_vti.c vti6: Add pmtu handling to vti6_xmit. 2015-06-01 16:03:43 -07:00
ip6mr.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
ipcomp6.c ipv6: White-space cleansing : Structure layouts 2014-08-24 22:37:52 -07:00
ipv6_sockglue.c ipv6: coding style: comparison for equality with NULL 2015-03-31 13:51:54 -04:00
Kconfig net: Identifier Locator Addressing module 2015-08-17 21:33:06 -07:00
Makefile net: Identifier Locator Addressing module 2015-08-17 21:33:06 -07:00
mcast_snoop.c net: fix wrong skb_get() usage / crash in IGMP/MLD parsing code 2015-08-13 17:08:39 -07:00
mcast.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
mip6.c net: Convert LIMIT_NETDEBUG to net_dbg_ratelimited 2014-11-11 14:10:31 -05:00
ndisc.c ipv6: ndisc: inherit metadata dst when creating ndisc requests 2015-08-20 15:42:37 -07:00
netfilter.c netfilter: bridge: forward IPv6 fragmented packets 2015-06-12 14:10:12 +02:00
output_core.c netfilter: don't pull include/linux/netfilter.h from netns headers 2015-06-18 21:14:31 +02:00
ping.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-09 23:38:02 -04:00
proc.c udp: Increment UDP_MIB_IGNOREDMULTI for arriving unmatched multicasts 2014-11-07 15:45:50 -05:00
protocol.c net: Export inet_offloads and inet6_offloads 2014-09-19 17:15:31 -04:00
raw.c ipv6: Nonlocal bind 2015-07-09 21:09:10 -07:00
reassembly.c inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the test 2015-07-26 21:00:15 -07:00
route.c ip_tunnels: convert the mode field of ip_tunnel_info to flags 2015-08-29 13:07:54 -07:00
sit.c ip_gre: Add support to collect tunnel metadata. 2015-08-10 14:03:54 -07:00
syncookies.c tcp: get_cookie_sock() consolidation 2015-06-07 15:19:52 -07:00
sysctl_net_ipv6.c ipv6: Implement different admin modes for automatic flow labels 2015-07-31 17:07:11 -07:00
tcp_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-13 16:23:11 -07:00
tcpv6_offload.c tcp: cleanup static functions 2015-02-28 16:56:51 -05:00
tunnel6.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00
udp_impl.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udp_offload.c ipv6: hash net ptr into fragmentation bucket selection 2015-03-25 14:07:04 -04:00
udp.c ipv6: trivial whitespace fix 2015-08-17 14:34:48 -07:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm6_input.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_mode_beet.c xfrm: simplify xfrm_address_t use 2015-03-31 13:58:35 -04:00
xfrm6_mode_ro.c ipv4/ipv6: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
xfrm6_mode_transport.c
xfrm6_mode_tunnel.c xfrm6: Fix IPv6 ECN decapsulation 2015-08-11 12:41:34 +02:00
xfrm6_output.c netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
xfrm6_policy.c xfrm: Use VRF master index if output device is enslaved 2015-08-25 11:25:09 -07:00
xfrm6_protocol.c xfrm6: Properly handle unsupported protocols 2014-05-06 07:08:38 +02:00
xfrm6_state.c ipv6: White-space cleansing : Line Layouts 2014-08-24 22:37:52 -07:00
xfrm6_tunnel.c ipv6: White-space cleansing : gaps between function and symbol export 2014-08-24 22:37:52 -07:00