On 05/16/2014 11:09 AM, Tejun Heo wrote: > 9395a4500404 ("cgroup: enable refcnting for root csses") enabled > reference counting for root csses (cgroup_subsys_states) so that > cgroup's self csses can be used to manage the lifetime of the > containing cgroups. > > Unfortunately, this change was incorrect. During early init, > cgrp_dfl_root self css refcnt is used. percpu_ref can't initialized > during early init and its initialization is deferred till > cgroup_init() time. This means that cpu was using percpu_ref which > wasn't properly initialized. Due to the way percpu variables are laid > out on x86, this didn't blow up immediately on x86 but ended up > incrementing and decrementing the percpu variable at offset zero, > whatever it may be; however, on other archs, this caused fault and > early boot failure. > > As cgroup self csses for root cgroups of non-dfl hierarchies need > working refcounting, we can't revert 9395a4500404. This patch adds > CSS_NO_REF which explicitly inhibits reference counting on the css and > sets it on all normal (non-self) csses and cgroup_dfl_root self css. > > v2: cgrp_dfl_root.self is the offending one. Set the flag on it. > > Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> > Reported-by: Stephen Warren <swarren@xxxxxxxxxxxxx> > Fixes: 9395a4500404 ("cgroup: enable refcnting for root csses") > --- > Hello, > > Can you try this one instead? Yes, this one works great, thanks. Tested-by: Stephen Warren <swarren@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html