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.
*/
/*
* Return in pmask the portion of a cpusets's cpus_allowed that
* are online. If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online cpus. If we get
- * all the way to the top and still haven't found any online cpus,
- * return cpu_online_mask. Or if passed a NULL cs from an exit'ing
- * task, return cpu_online_mask.
+ * until we find one that does have some online cpus. The top
+ * cpuset always has some cpus online.
*
* One way or another, we guarantee to return some non-empty subset
* of cpu_online_mask.
*
* Call with callback_mutex held.
*/
-
static void guarantee_online_cpus(const struct cpuset *cs,
struct cpumask *pmask)
{
- while (cs && !cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
+ while (!cpumask_intersects(cs->cpus_allowed, cpu_online_mask))
cs = parent_cs(cs);
- if (cs)
- cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
- else
- cpumask_copy(pmask, cpu_online_mask);
- BUG_ON(!cpumask_intersects(pmask, cpu_online_mask));
+ cpumask_and(pmask, cs->cpus_allowed, cpu_online_mask);
}
/*
* Return in *pmask the portion of a cpusets's mems_allowed that
* are online, with memory. If none are online with memory, walk
* up the cpuset hierarchy until we find one that does have some
- * online mems. If we get all the way to the top and still haven't
- * found any online mems, return node_states[N_MEMORY].
+ * online mems. The top cpuset always has some mems online.
*
* One way or another, we guarantee to return some non-empty subset
* of node_states[N_MEMORY].
*
* Call with callback_mutex held.
*/
-
static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
{
- while (cs && !nodes_intersects(cs->mems_allowed,
- node_states[N_MEMORY]))
+ while (!nodes_intersects(cs->mems_allowed, node_states[N_MEMORY]))
cs = parent_cs(cs);
- if (cs)
- nodes_and(*pmask, cs->mems_allowed,
- node_states[N_MEMORY]);
- else
- *pmask = node_states[N_MEMORY];
- BUG_ON(!nodes_intersects(*pmask, node_states[N_MEMORY]));
+ nodes_and(*pmask, cs->mems_allowed, node_states[N_MEMORY]);
}
/*
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)
cgroup_taskset_for_each(task, cgrp, tset) {
/*
- * Kthreads bound to specific cpus cannot be moved to a new
- * cpuset; we cannot change their cpu affinity and
- * isolating such threads by their set of allowed nodes is
- * unnecessary. Thus, cpusets are not applicable for such
- * threads. This prevents checking for success of
- * set_cpus_allowed_ptr() on all attached tasks before
- * cpus_allowed may be changed.
+ * Kthreads which disallow setaffinity shouldn't be moved
+ * to a new cpuset; we don't want to change their cpu
+ * affinity and isolating such threads by their set of
+ * allowed nodes is unnecessary. Thus, cpusets are not
+ * applicable for such threads. This prevents checking for
+ * success of set_cpus_allowed_ptr() on all attached tasks
+ * before cpus_allowed may be changed.
*/
ret = -EINVAL;
- if (task->flags & PF_THREAD_BOUND)
+ if (task->flags & PF_NO_SETAFFINITY)
goto out_unlock;
ret = security_task_setscheduler(task);
if (ret)
static void cpuset_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
{
- /* static bufs protected by cpuset_mutex */
- static nodemask_t cpuset_attach_nodemask_from;
+ /* static buf protected by cpuset_mutex */
static nodemask_t cpuset_attach_nodemask_to;
struct mm_struct *mm;
struct task_struct *task;
* Change mm, possibly for multiple threads in a threadgroup. This is
* expensive and may sleep.
*/
- cpuset_attach_nodemask_from = oldcs->mems_allowed;
cpuset_attach_nodemask_to = cs->mems_allowed;
mm = get_task_mm(leader);
if (mm) {
mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
if (is_memory_migrate(cs))
- cpuset_migrate_mm(mm, &cpuset_attach_nodemask_from,
+ cpuset_migrate_mm(mm, &oldcs->mems_allowed,
&cpuset_attach_nodemask_to);
mmput(mm);
}
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,
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();
+ }
}
/**
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)
rcu_read_lock();
cs = task_cs(tsk);
- if (cs)
- do_set_cpus_allowed(tsk, cs->cpus_allowed);
+ do_set_cpus_allowed(tsk, cs->cpus_allowed);
rcu_read_unlock();
/*
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.
*/
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();
}
/*
* and we take cpuset_mutex, keeping cpuset_attach() from changing it
* anyway.
*/
-static int proc_cpuset_show(struct seq_file *m, void *unused_v)
+int proc_cpuset_show(struct seq_file *m, void *unused_v)
{
struct pid *pid;
struct task_struct *tsk;
out:
return retval;
}
-
-static int cpuset_open(struct inode *inode, struct file *file)
-{
- struct pid *pid = PROC_I(inode)->pid;
- return single_open(file, proc_cpuset_show, pid);
-}
-
-const struct file_operations proc_cpuset_operations = {
- .open = cpuset_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
#endif /* CONFIG_PROC_PID_CPUSET */
/* Display task mems_allowed in /proc/<pid>/status file. */
projects / ~andy / linux / blobdiff