From 390a36aadf39e241c83035469aae48ed1a144088 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 9 Jul 2014 16:48:54 +0800 Subject: [PATCH] cpuset: refactor cpuset_hotplug_update_tasks() We mix the handling for both default hierarchy and legacy hierarchy in the same function, and it's quite messy, so split into two functions. Signed-off-by: Li Zefan Signed-off-by: Tejun Heo --- kernel/cpuset.c | 121 ++++++++++++++++++++++++++---------------------- 1 file changed, 66 insertions(+), 55 deletions(-) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 4b409d2ecbb9..41822e2027c1 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2080,6 +2080,65 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) } } +static void hotplug_update_tasks_legacy(struct cpuset *cs, + struct cpumask *off_cpus, + nodemask_t *off_mems) +{ + bool is_empty; + + mutex_lock(&callback_mutex); + cpumask_andnot(cs->cpus_allowed, cs->cpus_allowed, off_cpus); + cpumask_andnot(cs->effective_cpus, cs->effective_cpus, off_cpus); + nodes_andnot(cs->mems_allowed, cs->mems_allowed, *off_mems); + nodes_andnot(cs->effective_mems, cs->effective_mems, *off_mems); + mutex_unlock(&callback_mutex); + + /* + * Don't call update_tasks_cpumask() if the cpuset becomes empty, + * as the tasks will be migratecd to an ancestor. + */ + if (!cpumask_empty(off_cpus) && !cpumask_empty(cs->cpus_allowed)) + update_tasks_cpumask(cs); + if (!nodes_empty(*off_mems) && !nodes_empty(cs->mems_allowed)) + update_tasks_nodemask(cs); + + is_empty = cpumask_empty(cs->cpus_allowed) || + nodes_empty(cs->mems_allowed); + + mutex_unlock(&cpuset_mutex); + + /* + * Move tasks to the nearest ancestor with execution resources, + * This is full cgroup operation which will also call back into + * cpuset. Should be done outside any lock. + */ + if (is_empty) + remove_tasks_in_empty_cpuset(cs); + + mutex_lock(&cpuset_mutex); +} + +static void hotplug_update_tasks(struct cpuset *cs, + struct cpumask *off_cpus, + nodemask_t *off_mems) +{ + mutex_lock(&callback_mutex); + cpumask_andnot(cs->effective_cpus, cs->effective_cpus, off_cpus); + if (cpumask_empty(cs->effective_cpus)) + cpumask_copy(cs->effective_cpus, + parent_cs(cs)->effective_cpus); + + nodes_andnot(cs->effective_mems, cs->effective_mems, *off_mems); + if (nodes_empty(cs->effective_mems)) + cs->effective_mems = parent_cs(cs)->effective_mems; + mutex_unlock(&callback_mutex); + + if (!cpumask_empty(off_cpus)) + update_tasks_cpumask(cs); + if (!nodes_empty(*off_mems)) + update_tasks_nodemask(cs); +} + /** * cpuset_hotplug_update_tasks - update tasks in a cpuset for hotunplug * @cs: cpuset in interest @@ -2092,9 +2151,6 @@ static void cpuset_hotplug_update_tasks(struct cpuset *cs) { static cpumask_t off_cpus; static nodemask_t off_mems; - bool is_empty; - bool on_dfl = cgroup_on_dfl(cs->css.cgroup); - retry: wait_event(cpuset_attach_wq, cs->attach_in_progress == 0); @@ -2109,61 +2165,16 @@ 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); - - /* Inherit the effective mask of the parent, if it becomes empty. */ - cpumask_andnot(cs->effective_cpus, cs->effective_cpus, &off_cpus); - if (on_dfl && cpumask_empty(cs->effective_cpus)) - cpumask_copy(cs->effective_cpus, parent_cs(cs)->effective_cpus); - mutex_unlock(&callback_mutex); - - /* - * If on_dfl, we need to update tasks' cpumask for empty cpuset to - * take on ancestor's cpumask. Otherwise, don't call - * update_tasks_cpumask() if the cpuset becomes empty, as the tasks - * in it will be migrated to an ancestor. - */ - if ((on_dfl && cpumask_empty(cs->cpus_allowed)) || - (!cpumask_empty(&off_cpus) && !cpumask_empty(cs->cpus_allowed))) - update_tasks_cpumask(cs); - - mutex_lock(&callback_mutex); - 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); - if (on_dfl && nodes_empty(cs->effective_mems)) - cs->effective_mems = parent_cs(cs)->effective_mems; - mutex_unlock(&callback_mutex); - - /* - * If on_dfl, we need to update tasks' nodemask for empty cpuset to - * take on ancestor's nodemask. Otherwise, don't call - * update_tasks_nodemask() if the cpuset becomes empty, as the - * tasks in it will be migratd to an ancestor. - */ - if ((on_dfl && nodes_empty(cs->mems_allowed)) || - (!nodes_empty(off_mems) && !nodes_empty(cs->mems_allowed))) - update_tasks_nodemask(cs); - - is_empty = cpumask_empty(cs->cpus_allowed) || - nodes_empty(cs->mems_allowed); + if (cgroup_on_dfl(cs->css.cgroup)) + hotplug_update_tasks(cs, &off_cpus, &off_mems); + else + hotplug_update_tasks_legacy(cs, &off_cpus, &off_mems); mutex_unlock(&cpuset_mutex); - - /* - * If on_dfl, we'll keep tasks in empty cpusets. - * - * Otherwise move tasks to the nearest ancestor with execution - * resources. This is full cgroup operation which will - * also call back into cpuset. Should be done outside any lock. - */ - if (!on_dfl && is_empty) - remove_tasks_in_empty_cpuset(cs); } /**