On 2012/9/14 3:20, Tejun Heo wrote: > 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@xxxxxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxx> > Cc: Li Zefan <lizefan@xxxxxxxxxx> > Cc: Glauber Costa <glommer@xxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Paul Turner <pjt@xxxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Thomas Graf <tgraf@xxxxxxx> > Cc: Serge E. Hallyn <serue@xxxxxxxxxx> > Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> > Cc: Paul Mackerras <paulus@xxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx> > Cc: Neil Horman <nhorman@xxxxxxxxxxxxx> > Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Acked-by: Li Zefan <lizefan@xxxxxxxxxx> _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
