OpenCloudOS-Kernel/net/ipv4
Vladimir Davydov 9ee11ba425 memcg: do not allow to disable tcp accounting after limit is set
There are two bits defined for cg_proto->flags - MEMCG_SOCK_ACTIVATED
and MEMCG_SOCK_ACTIVE - both are set in tcp_update_limit, but the former
is never cleared while the latter can be cleared by unsetting the limit.
This allows to disable tcp socket accounting for new sockets after it
was enabled by writing -1 to memory.kmem.tcp.limit_in_bytes while still
guaranteeing that memcg_socket_limit_enabled static key will be
decremented on memcg destruction.

This functionality looks dubious, because it is not clear what a use
case would be.  By enabling tcp accounting a user accepts the price.  If
they then find the performance degradation unacceptable, they can always
restart their workload with tcp accounting disabled.  It does not seem
there is any need to flip it while the workload is running.

Besides, it contradicts to how kmem accounting API works: writing
whatever to memory.kmem.limit_in_bytes enables kmem accounting for the
cgroup in question, after which it cannot be disabled.  Therefore one
might expect that writing -1 to memory.kmem.tcp.limit_in_bytes just
enables socket accounting w/o limiting it, which might be useful by
itself, but it isn't true.

Since this API peculiarity is not documented anywhere, I propose to drop
it.  This will allow to simplify the code by dropping cg_proto->flags.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14 16:00:49 -08:00
..
netfilter netfilter: nf_tables: release objects on netns destruction 2015-12-28 18:34:35 +01:00
Kconfig net: diag: Support destroying TCP sockets. 2015-12-15 23:26:52 -05:00
Makefile tcp: track the packet timings in RACK 2015-10-21 07:00:48 -07:00
af_inet.c net: add validation for the socket syscall protocol argument 2015-12-14 16:09:30 -05:00
ah4.c ah4: Fix error return in ah_input(). 2015-08-25 13:38:50 -07:00
arp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-20 06:08:27 -07:00
cipso_ipv4.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
datagram.c net: Set sk_txhash from a random number 2015-07-29 22:44:04 -07:00
devinet.c netlink: Rightsize IFLA_AF_SPEC size calculation 2015-10-21 19:15:20 -07:00
esp4.c esp4: Switch to new AEAD interface 2015-05-28 11:23:20 +08:00
fib_frontend.c net: Flush local routes when device changes vrf association 2015-12-13 23:58:44 -05:00
fib_lookup.h ipv4: consider TOS in fib_select_default 2015-07-24 22:46:11 -07:00
fib_rules.c net: ipv6: use common fib_default_rule_pref 2015-09-09 14:19:50 -07:00
fib_semantics.c net: Fix prefsrc lookups 2015-11-04 21:34:37 -05:00
fib_trie.c fib_trie: leaf_walk_rcu should not compute key if key is less than pn->key 2015-10-27 18:14:51 -07:00
fou.c udp: restrict offloads to one namespace 2016-01-10 17:28:24 -05:00
gre_demux.c gre: Remove support for sharing GRE protocol hook. 2015-08-10 14:03:54 -07:00
gre_offload.c ipv6: gre: support SIT encapsulation 2015-10-26 22:01:18 -07:00
icmp.c Revert "ipv4/icmp: redirect messages can use the ingress daddr as source" 2015-10-14 06:01:07 -07:00
igmp.c ipv4: igmp: Allow removing groups from a removed interface 2015-12-03 12:07:05 -05:00
inet_connection_sock.c tcp: ensure proper barriers in lockless contexts 2015-11-15 18:36:38 -05:00
inet_diag.c net: diag: Support SOCK_DESTROY for inet sockets. 2015-12-15 23:26:51 -05:00
inet_fragment.c inet: kill unused skb_free op 2016-01-05 22:25:57 -05:00
inet_hashtables.c tcp/dccp: fix hashdance race for passive sessions 2015-10-23 05:42:21 -07:00
inet_lro.c lro: remove dead code 2013-12-29 16:34:25 -05:00
inet_timewait_sock.c tcp/dccp: fix timewait races in timer handling 2015-09-21 16:32:29 -07:00
inetpeer.c net: Add helper function to compare inetpeer addresses 2015-08-28 13:32:36 -07:00
ip_forward.c net: Pass net into dst_output and remove dst_output_okfn 2015-10-08 04:26:54 -07:00
ip_fragment.c inet: kill unused skb_free op 2016-01-05 22:25:57 -05:00
ip_gre.c ip_tunnel: Move stats update to iptunnel_xmit() 2015-12-25 23:32:23 -05:00
ip_input.c ipv4: Pass struct net into ip_defrag and ip_check_defrag 2015-10-12 19:44:16 -07:00
ip_options.c ipv4: coding style: comparison for inequality with NULL 2015-04-03 12:11:15 -04:00
ip_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
ip_sockglue.c ipv4: fix a potential deadlock in mcast getsockopt() path 2015-11-04 21:29:59 -05:00
ip_tunnel.c ip_tunnel: Move stats update to iptunnel_xmit() 2015-12-25 23:32:23 -05:00
ip_tunnel_core.c ipv4: fix endianness warnings in ip_tunnel_core.c 2016-01-08 21:30:43 -05:00
ip_vti.c ip_tunnel: Move stats update to iptunnel_xmit() 2015-12-25 23:32:23 -05:00
ipcomp.c ipv4: coding style: comparison for equality with NULL 2015-04-03 12:11:15 -04:00
ipconfig.c net/ipv4/ipconfig: Rejoin broken lines in console output 2015-11-24 12:00:09 -05:00
ipip.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-31 18:20:10 -05:00
ipmr.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-03 21:09:12 -05:00
netfilter.c ipv4: Pass struct net into ip_route_me_harder 2015-09-29 20:21:32 +02:00
ping.c ipv4: eliminate lock count warnings in ping.c 2016-01-08 21:30:43 -05:00
proc.c net: track success and failure of TCP PMTU probing 2015-07-21 22:36:33 -07:00
protocol.c net: Export inet_offloads and inet6_offloads 2014-09-19 17:15:31 -04:00
raw.c net: Propagate lookup failure in l3mdev_get_saddr to caller 2016-01-04 22:58:30 -05:00
route.c net: Do not drop to make_route if oif is l3mdev 2015-10-08 05:18:47 -07:00
syncookies.c net: Allow accepted sockets to be bound to l3mdev domain 2015-12-18 14:43:38 -05:00
sysctl_net_ipv4.c ipv4: Namespecify the tcp_keepalive_intvl sysctl knob 2016-01-10 17:32:09 -05:00
tcp.c net: tcp: deal with listen sockets properly in tcp_abort. 2015-12-22 16:01:47 -05:00
tcp_bic.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_cdg.c tcp: do not slow start when cwnd equals ssthresh 2015-07-09 14:22:52 -07:00
tcp_cong.c tcp: remove tcp_ecn_make_synack() socket argument 2015-09-25 13:00:38 -07:00
tcp_cubic.c tcp_cubic: do not set epoch_start in the future 2015-09-17 22:35:07 -07:00
tcp_dctcp.c tcp: allow dctcp alpha to drop to zero 2015-10-23 02:46:52 -07:00
tcp_diag.c net: diag: Support destroying TCP sockets. 2015-12-15 23:26:52 -05:00
tcp_fastopen.c tcp/dccp: fix hashdance race for passive sessions 2015-10-23 05:42:21 -07:00
tcp_highspeed.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_htcp.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_hybla.c tcp: do not slow start when cwnd equals ssthresh 2015-07-09 14:22:52 -07:00
tcp_illinois.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-06 22:54:18 -05:00
tcp_ipv4.c ipv4: Namespecify the tcp_keepalive_intvl sysctl knob 2016-01-10 17:32:09 -05:00
tcp_lp.c tcp: remove in_flight parameter from cong_avoid() methods 2014-05-03 19:23:07 -04:00
tcp_memcontrol.c memcg: do not allow to disable tcp accounting after limit is set 2016-01-14 16:00:49 -08:00
tcp_metrics.c net: Add helper function to compare inetpeer addresses 2015-08-28 13:32:36 -07:00
tcp_minisocks.c tcp: honour SO_BINDTODEVICE for TW_RST case too 2015-12-22 17:03:05 -05:00
tcp_offload.c tcp: reserve tcp_skb_mss() to tcp stack 2015-06-11 16:33:10 -07:00
tcp_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-17 22:08:28 -05:00
tcp_probe.c tcp: whitespace fixes 2014-09-01 18:12:45 -07:00
tcp_recovery.c tcp: use RACK to detect losses 2015-10-21 07:00:53 -07:00
tcp_scalable.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_timer.c ipv4: Namespecify the tcp_keepalive_intvl sysctl knob 2016-01-10 17:32:09 -05:00
tcp_vegas.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_vegas.h tcp: prepare CC get_info() access from getsockopt() 2015-04-29 17:10:38 -04:00
tcp_veno.c tcp: add tcp_in_slow_start helper 2015-07-09 14:22:52 -07:00
tcp_westwood.c tcp_westwood: fix tcp_westwood_info() 2015-05-05 19:50:09 -04:00
tcp_yeah.c tcp_yeah: don't set ssthresh below 2 2016-01-11 17:25:16 -05:00
tunnel4.c
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-06 22:54:18 -05:00
udp_diag.c soreuseport: setsockopt SO_ATTACH_REUSEPORT_[CE]BPF 2016-01-04 22:49:59 -05:00
udp_impl.h net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
udp_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
udp_tunnel.c ip_tunnel: Move stats update to iptunnel_xmit() 2015-12-25 23:32:23 -05:00
udplite.c net: Eliminate no_check from protosw 2014-05-23 16:28:53 -04:00
xfrm4_input.c netfilter: Pass net into okfn 2015-09-17 17:18:37 -07:00
xfrm4_mode_beet.c ipv4: ERROR: code indent should use tabs where possible 2013-12-26 13:43:21 -05:00
xfrm4_mode_transport.c
xfrm4_mode_tunnel.c ipv4: hash net ptr into fragmentation bucket selection 2015-03-25 14:07:04 -04:00
xfrm4_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-24 06:54:12 -07:00
xfrm4_policy.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2015-12-22 16:26:31 -05:00
xfrm4_protocol.c xfrm4: Remove duplicate semicolon 2014-06-30 07:49:47 +02:00
xfrm4_state.c inet: make no_pmtu_disc per namespace and kill ipv4_config 2013-12-18 16:58:20 -05:00
xfrm4_tunnel.c sit: add IPv4 over IPv4 support 2013-05-31 17:19:05 -07:00