Now we've used effective cpumasks to enforce hierarchical manner,
we can use cs->{cpus,mems}_allowed as configured masks.Configured masks can be changed by writing cpuset.cpus and cpuset.mems only. The new behaviors are: - They won't be changed by hotplug anymore. - They won't be limited by its parent's masks. This ia a behavior change, but won't take effect unless mount with sane_behavior. v2: - Add comments to explain the differences between configured masks and effective masks. Signed-off-by: Li Zefan <[email protected]> --- kernel/cpuset.c | 51 ++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 11 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 040ec59..e47115e 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -82,6 +82,26 @@ struct cpuset { unsigned long flags; /* "unsigned long" so bitops work */ + /* + * If sane_behavior is set: + * + * The user-configured masks can only be changed by writing to + * cpuset.cpus and cpuset.mems, and won't be limited by the + * parent masks. + * + * The effective masks is the real masks that apply to the tasks + * in the cpuset. They may be changed if the configured masks are + * changed or hotplug happens. + * + * effective_mask == configured_mask & parent's effective_mask, + * and if it ends up empty, it will inherit the parent's mask. + * + * + * If sane_behavior is not set: + * + * The user-configured masks are always the same with effective masks. + */ + /* user-configured CPUs and Memory Nodes allow to tasks */ cpumask_var_t cpus_allowed; nodemask_t mems_allowed; @@ -455,9 +475,13 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial) par = parent_cs(cur); - /* We must be a subset of our parent cpuset */ + /* + * We must be a subset of our parent cpuset, unless sane_behavior + * flag is set. + */ ret = -EACCES; - if (!is_cpuset_subset(trial, par)) + if (!cgroup_sane_behavior(cur->css.cgroup) && + !is_cpuset_subset(trial, par)) goto out; /* @@ -779,7 +803,7 @@ static void rebuild_sched_domains_locked(void) * passing doms with offlined cpu to partition_sched_domains(). * Anyways, hotplug work item will rebuild sched domains. */ - if (!cpumask_equal(top_cpuset.cpus_allowed, cpu_active_mask)) + if (!cpumask_equal(top_cpuset.effective_cpus, cpu_active_mask)) goto out; /* Generate domain masks and attrs */ @@ -2191,11 +2215,12 @@ retry: goto retry; } - cpumask_andnot(&off_cpus, cs->cpus_allowed, top_cpuset.cpus_allowed); - nodes_andnot(off_mems, cs->mems_allowed, top_cpuset.mems_allowed); + cpumask_andnot(&off_cpus, cs->effective_cpus, top_cpuset.effective_cpus); + nodes_andnot(off_mems, cs->effective_mems, top_cpuset.effective_mems); mutex_lock(&callback_mutex); - cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); + if (!sane) + cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, &off_cpus); /* Inherit the effective mask of the parent, if it becomes empty. */ cpumask_andnot(cs->effective_cpus, cs->effective_cpus, &off_cpus); @@ -2214,7 +2239,8 @@ retry: update_tasks_cpumask(cs, NULL); mutex_lock(&callback_mutex); - nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); + if (!sane) + nodes_andnot(cs->mems_allowed, cs->mems_allowed, off_mems); /* Inherit the effective mask of the parent, if it becomes empty */ nodes_andnot(cs->effective_mems, cs->effective_mems, off_mems); @@ -2269,6 +2295,7 @@ static void cpuset_hotplug_workfn(struct work_struct *work) static cpumask_t new_cpus; static nodemask_t new_mems; bool cpus_updated, mems_updated; + bool sane = cgroup_sane_behavior(top_cpuset.css.cgroup); mutex_lock(&cpuset_mutex); @@ -2276,13 +2303,14 @@ static void cpuset_hotplug_workfn(struct work_struct *work) cpumask_copy(&new_cpus, cpu_active_mask); new_mems = node_states[N_MEMORY]; - cpus_updated = !cpumask_equal(top_cpuset.cpus_allowed, &new_cpus); - mems_updated = !nodes_equal(top_cpuset.mems_allowed, new_mems); + cpus_updated = !cpumask_equal(top_cpuset.effective_cpus, &new_cpus); + mems_updated = !nodes_equal(top_cpuset.effective_mems, new_mems); /* synchronize cpus_allowed to cpu_active_mask */ if (cpus_updated) { mutex_lock(&callback_mutex); - cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); + if (!sane) + cpumask_copy(top_cpuset.cpus_allowed, &new_cpus); cpumask_copy(top_cpuset.effective_cpus, &new_cpus); mutex_unlock(&callback_mutex); /* we don't mess with cpumasks of tasks in top_cpuset */ @@ -2291,7 +2319,8 @@ static void cpuset_hotplug_workfn(struct work_struct *work) /* synchronize mems_allowed to N_MEMORY */ if (mems_updated) { mutex_lock(&callback_mutex); - top_cpuset.mems_allowed = new_mems; + if (!sane) + top_cpuset.mems_allowed = new_mems; top_cpuset.effective_mems = new_mems; mutex_unlock(&callback_mutex); update_tasks_nodemask(&top_cpuset, NULL); -- 1.8.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
