linux/net/sched
Tejun Heo 8c7f6edbda cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them
Currently, cgroup hierarchy support is a mess.  cpu related subsystems
behave correctly - configuration, accounting and control on a parent
properly cover its children.  blkio and freezer completely ignore
hierarchy and treat all cgroups as if they're directly under the root
cgroup.  Others show yet different behaviors.

These differing interpretations of cgroup hierarchy make using cgroup
confusing and it impossible to co-mount controllers into the same
hierarchy and obtain sane behavior.

Eventually, we want full hierarchy support from all subsystems and
probably a unified hierarchy.  Users using separate hierarchies
expecting completely different behaviors depending on the mounted
subsystem is deterimental to making any progress on this front.

This patch adds cgroup_subsys.broken_hierarchy and sets it to %true
for controllers which are lacking in hierarchy support.  The goal of
this patch is two-fold.

* Move users away from using hierarchy on currently non-hierarchical
  subsystems, so that implementing proper hierarchy support on those
  doesn't surprise them.

* Keep track of which controllers are broken how and nudge the
  subsystems to implement proper hierarchy support.

For now, start with a single warning message.  We can whine louder
later on.

v2: Fixed a typo spotted by Michal. Warning message updated.

v3: Updated memcg part so that it doesn't generate warning in the
    cases where .use_hierarchy=false doesn't make the behavior
    different from root.use_hierarchy=true.  Fixed a typo spotted by
    Glauber.

v4: Check ->broken_hierarchy after cgroup creation is complete so that
    ->create() can affect the result per Michal.  Dropped unnecessary
    memcg root handling per Michal.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2012-09-14 12:01:16 -07:00
..
act_api.c pkt_sched: act_api: Move away from NLMSG_PUT(). 2012-06-26 21:39:32 -07:00
act_csum.c ipv6: correct the ipv6 option name - Pad0 to Pad1 2012-05-17 15:49:51 -04:00
act_gact.c net_sched: gact: Fix potential panic in tcf_gact(). 2012-08-03 16:47:24 -07:00
act_ipt.c net_sched: act: Delete estimator in error path. 2012-08-06 13:30:01 -07:00
act_mirred.c act_mirred: do not drop packets when fails to mirror it 2012-08-16 14:54:44 -07:00
act_nat.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
act_pedit.c net_sched: act: Delete estimator in error path. 2012-08-06 13:30:01 -07:00
act_police.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
act_simple.c net_sched: act: Delete estimator in error path. 2012-08-06 13:30:01 -07:00
act_skbedit.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_api.c pkt_sched: cls_api: Move away from NLMSG_NEW(). 2012-06-26 21:54:15 -07:00
cls_basic.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_cgroup.c cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them 2012-09-14 12:01:16 -07:00
cls_flow.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_fw.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_route.c ipv4: Prepare for change of rt->rt_iif encoding. 2012-07-23 16:36:26 -07:00
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_tcindex.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
cls_u32.c net: Convert net_ratelimit uses to net_<level>_ratelimited 2012-05-15 13:45:03 -04:00
em_canid.c net: em_canid: Ematch rule to match CAN frames according to their identifiers 2012-07-04 13:07:05 +02:00
em_cmp.c net_sched: cleanups 2011-01-19 23:31:12 -08:00
em_ipset.c net: sched: add ipset ematch 2012-07-12 07:54:46 -07:00
em_meta.c ipv4: Prepare for change of rt->rt_iif encoding. 2012-07-23 16:36:26 -07:00
em_nbyte.c net_sched: cleanups 2011-01-19 23:31:12 -08:00
em_text.c net_sched: cleanups 2011-01-19 23:31:12 -08:00
em_u32.c net_sched: cleanups 2011-01-19 23:31:12 -08:00
ematch.c net: Convert net_ratelimit uses to net_<level>_ratelimited 2012-05-15 13:45:03 -04:00
Kconfig net: sched: add ipset ematch 2012-07-12 07:54:46 -07:00
Makefile net: sched: add ipset ematch 2012-07-12 07:54:46 -07:00
sch_api.c pkt_sched: sch_api: Move away from NLMSG_NEW(). 2012-06-26 21:54:15 -07:00
sch_atm.c sch_atm.c: get rid of poinless extern 2012-06-01 10:37:18 -04:00
sch_blackhole.c
sch_cbq.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_choke.c net: sched: factorize code (qdisc_drop()) 2012-05-04 11:50:05 -04:00
sch_codel.c fq_codel: should use qdisc backlog as threshold 2012-05-16 15:30:26 -04:00
sch_drr.c net_sched: update bstats in dequeue() 2012-05-10 23:33:01 -04:00
sch_dsmark.c net: sched: factorize code (qdisc_drop()) 2012-05-04 11:50:05 -04:00
sch_fifo.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_fq_codel.c fq_codel: should use qdisc backlog as threshold 2012-05-16 15:30:26 -04:00
sch_generic.c net: Convert net_ratelimit uses to net_<level>_ratelimited 2012-05-15 13:45:03 -04:00
sch_gred.c net: Convert net_ratelimit uses to net_<level>_ratelimited 2012-05-15 13:45:03 -04:00
sch_hfsc.c net_sched: update bstats in dequeue() 2012-05-10 23:33:01 -04:00
sch_htb.c net_sched: update bstats in dequeue() 2012-05-10 23:33:01 -04:00
sch_ingress.c net_sched: factorize qdisc stats handling 2011-01-10 16:07:54 -08:00
sch_mq.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
sch_mqprio.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_multiq.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_netem.c netem: refine early skb orphaning 2012-07-16 23:08:33 -07:00
sch_plug.c net_sched: sch_plug: plug_qdisc_ops is static 2012-02-13 16:04:40 -05:00
sch_prio.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_qfq.c sched: add missing group change to qfq_change_class 2012-08-08 16:02:05 -07:00
sch_red.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_sfb.c sch_sfb: Fix missing NULL check 2012-07-12 08:33:18 -07:00
sch_sfq.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_tbf.c pkt_sched: Stop using NLA_PUT*(). 2012-04-01 18:11:37 -04:00
sch_teql.c sch_teql: Convert over to dev_neigh_lookup_skb(). 2012-07-05 01:09:06 -07:00