linux-stable/net
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
..
6lowpan 6lowpan: fix debugfs interface entry name 2015-12-20 08:21:00 +01:00
9p ... and a couple in net/9p 2016-01-04 10:29:17 -05:00
802
8021q net: Rename NETIF_F_ALL_CSUM to NETIF_F_CSUM_MASK 2015-12-15 16:50:08 -05:00
appletalk
atm net: Generalise wq_has_sleeper helper 2015-11-30 14:47:33 -05:00
ax25 net: add validation for the socket syscall protocol argument 2015-12-14 16:09:30 -05:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
bluetooth Bluetooth: avoid rebuilding hci_sock all the time 2016-01-06 16:36:44 +01:00
bridge bridge: Reflect MDB entries to hardware 2016-01-10 16:50:21 -05:00
caif net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA 2015-12-01 15:45:05 -05:00
can can: avoid using timeval for uapi 2015-10-13 17:42:34 +02:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2015-11-13 09:24:40 -08:00
core net: bpf: reject invalid shifts 2016-01-12 17:06:53 -05:00
dcb net/dcb: make dcbnl.c explicitly non-modular 2015-10-09 07:52:27 -07:00
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-03 21:09:12 -05:00
decnet net: add validation for the socket syscall protocol argument 2015-12-14 16:09:30 -05:00
dns_resolver net: dns_resolver: convert time_t to time64_t 2015-11-18 16:27:46 -05:00
dsa dsa: Register netdev before phy 2016-01-07 14:31:26 -05:00
ethernet net: Add eth_platform_get_mac_address() helper. 2016-01-06 16:31:56 -05:00
hsr net/hsr: fix a warning message 2015-11-23 14:56:15 -05:00
ieee802154 inet: kill unused skb_free op 2016-01-05 22:25:57 -05:00
ipv4 memcg: do not allow to disable tcp accounting after limit is set 2016-01-14 16:00:49 -08:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
ipx
irda net: add validation for the socket syscall protocol argument 2015-12-14 16:09:30 -05:00
iucv iucv: call skb_linearize() when needed 2015-12-14 16:16:44 -05:00
key af_key: fix two typos 2015-10-23 03:05:19 -07:00
l2tp l2tp: rely on ppp layer for skb scrubbing 2016-01-04 16:45:24 -05:00
l3mdev net: Add netif_is_l3_slave 2015-10-07 04:27:43 -07:00
lapb
llc
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-17 22:08:28 -05:00
mac802154 mac802154: constify ieee802154_llsec_ops structure 2016-01-04 20:40:41 +01:00
mpls Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-17 22:08:28 -05:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2016-01-08 20:53:16 -05:00
netlabel
netlink netlink: add a start callback for starting a netlink dump 2015-12-15 23:25:20 -05:00
netrom
nfc NFC 4.5 pull request 2016-01-04 21:48:15 -05:00
openvswitch openvswitch: update kernel doc for struct vport 2016-01-10 23:49:21 -05:00
packet packet: Allow packets with only a header (but no payload) 2015-11-29 22:17:17 -05:00
phonet phonet: properly unshare skbs in phonet_rcv() 2016-01-12 12:05:38 -05:00
rds RDS: don't pretend to use cpu notifiers 2015-12-22 15:23:05 -05:00
rfkill Bluetooth: hci_bcm: move all Broadcom ACPI IDs to BCM HCI driver 2016-01-04 19:22:05 +01:00
rose
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-01-12 18:57:02 -08:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
sunrpc kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
switchdev switchdev: Adding MDB entry offload 2016-01-10 16:50:20 -05:00
tipc ip_tunnel: Move stats update to iptunnel_xmit() 2015-12-25 23:32:23 -05:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
vmw_vsock Revert "Merge branch 'vsock-virtio'" 2015-12-08 21:55:49 -05:00
wimax
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-12-17 22:08:28 -05:00
x25
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2015-12-22 16:26:31 -05:00
compat.c
Kconfig net, sched: add clsact qdisc 2016-01-10 22:13:15 -05:00
Makefile
socket.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
sysctl_net.c net: sysctl: fix a kmemleak warning 2015-10-23 06:22:08 -07:00