diff options
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 115 |
1 files changed, 28 insertions, 87 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 027a6f65f2ad..12331120767c 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -265,17 +265,6 @@ static DEFINE_MUTEX(cpuset_mutex); static DEFINE_MUTEX(callback_mutex); /* - * cpuset_buffer_lock protects both the cpuset_name and cpuset_nodelist - * buffers. They are statically allocated to prevent using excess stack - * when calling cpuset_print_task_mems_allowed(). - */ -#define CPUSET_NAME_LEN (128) -#define CPUSET_NODELIST_LEN (256) -static char cpuset_name[CPUSET_NAME_LEN]; -static char cpuset_nodelist[CPUSET_NODELIST_LEN]; -static DEFINE_SPINLOCK(cpuset_buffer_lock); - -/* * CPU / memory hotplug is handled asynchronously. */ static struct workqueue_struct *cpuset_propagate_hotplug_wq; @@ -780,25 +769,26 @@ static void rebuild_sched_domains_locked(void) lockdep_assert_held(&cpuset_mutex); get_online_cpus(); + /* + * We have raced with CPU hotplug. Don't do anything to avoid + * 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)) + goto out; + /* Generate domain masks and attrs */ ndoms = generate_sched_domains(&doms, &attr); /* Have scheduler rebuild the domains */ partition_sched_domains(ndoms, doms, attr); - +out: put_online_cpus(); } #else /* !CONFIG_SMP */ static void rebuild_sched_domains_locked(void) { } - -static int generate_sched_domains(cpumask_var_t **domains, - struct sched_domain_attr **attributes) -{ - *domains = NULL; - return 1; -} #endif /* CONFIG_SMP */ void rebuild_sched_domains(void) @@ -2005,50 +1995,6 @@ int __init cpuset_init(void) return 0; } -/** - * cpuset_do_move_task - move a given task to another cpuset - * @tsk: pointer to task_struct the task to move - * @scan: struct cgroup_scanner contained in its struct cpuset_hotplug_scanner - * - * Called by cgroup_scan_tasks() for each task in a cgroup. - * Return nonzero to stop the walk through the tasks. - */ -static void cpuset_do_move_task(struct task_struct *tsk, - struct cgroup_scanner *scan) -{ - struct cgroup *new_cgroup = scan->data; - - cgroup_lock(); - cgroup_attach_task(new_cgroup, tsk); - cgroup_unlock(); -} - -/** - * move_member_tasks_to_cpuset - move tasks from one cpuset to another - * @from: cpuset in which the tasks currently reside - * @to: cpuset to which the tasks will be moved - * - * Called with cpuset_mutex held - * callback_mutex must not be held, as cpuset_attach() will take it. - * - * The cgroup_scan_tasks() function will scan all the tasks in a cgroup, - * calling callback functions for each. - */ -static void move_member_tasks_to_cpuset(struct cpuset *from, struct cpuset *to) -{ - struct cgroup_scanner scan; - - scan.cg = from->css.cgroup; - scan.test_task = NULL; /* select all tasks in cgroup */ - scan.process_task = cpuset_do_move_task; - scan.heap = NULL; - scan.data = to->css.cgroup; - - if (cgroup_scan_tasks(&scan)) - printk(KERN_ERR "move_member_tasks_to_cpuset: " - "cgroup_scan_tasks failed\n"); -} - /* * If CPU and/or memory hotplug handlers, below, unplug any CPUs * or memory nodes, we need to walk over the cpuset hierarchy, @@ -2069,7 +2015,12 @@ static void remove_tasks_in_empty_cpuset(struct cpuset *cs) nodes_empty(parent->mems_allowed)) parent = parent_cs(parent); - move_member_tasks_to_cpuset(cs, parent); + if (cgroup_transfer_tasks(parent->css.cgroup, cs->css.cgroup)) { + rcu_read_lock(); + printk(KERN_ERR "cpuset: failed to transfer tasks out of empty cpuset %s\n", + cgroup_name(cs->css.cgroup)); + rcu_read_unlock(); + } } /** @@ -2222,17 +2173,8 @@ static void cpuset_hotplug_workfn(struct work_struct *work) flush_workqueue(cpuset_propagate_hotplug_wq); /* rebuild sched domains if cpus_allowed has changed */ - if (cpus_updated) { - struct sched_domain_attr *attr; - cpumask_var_t *doms; - int ndoms; - - mutex_lock(&cpuset_mutex); - ndoms = generate_sched_domains(&doms, &attr); - mutex_unlock(&cpuset_mutex); - - partition_sched_domains(ndoms, doms, attr); - } + if (cpus_updated) + rebuild_sched_domains(); } void cpuset_update_active_cpus(bool cpu_online) @@ -2594,6 +2536,8 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, return nodes_intersects(tsk1->mems_allowed, tsk2->mems_allowed); } +#define CPUSET_NODELIST_LEN (256) + /** * cpuset_print_task_mems_allowed - prints task's cpuset and mems_allowed * @task: pointer to task_struct of some task. @@ -2604,25 +2548,22 @@ int cpuset_mems_allowed_intersects(const struct task_struct *tsk1, */ void cpuset_print_task_mems_allowed(struct task_struct *tsk) { - struct dentry *dentry; + /* Statically allocated to prevent using excess stack. */ + static char cpuset_nodelist[CPUSET_NODELIST_LEN]; + static DEFINE_SPINLOCK(cpuset_buffer_lock); - dentry = task_cs(tsk)->css.cgroup->dentry; - spin_lock(&cpuset_buffer_lock); + struct cgroup *cgrp = task_cs(tsk)->css.cgroup; - if (!dentry) { - strcpy(cpuset_name, "/"); - } else { - spin_lock(&dentry->d_lock); - strlcpy(cpuset_name, (const char *)dentry->d_name.name, - CPUSET_NAME_LEN); - spin_unlock(&dentry->d_lock); - } + rcu_read_lock(); + spin_lock(&cpuset_buffer_lock); nodelist_scnprintf(cpuset_nodelist, CPUSET_NODELIST_LEN, tsk->mems_allowed); printk(KERN_INFO "%s cpuset=%s mems_allowed=%s\n", - tsk->comm, cpuset_name, cpuset_nodelist); + tsk->comm, cgroup_name(cgrp), cpuset_nodelist); + spin_unlock(&cpuset_buffer_lock); + rcu_read_unlock(); } /* |