sched/walt: Accounting for number of irqs pending on each core
[firefly-linux-kernel-4.4.55.git] / kernel / cpuset.c
index 10ae73611d80a560977aa554d6cbedee78bec19a..e2e294d997e0c9b8b5f26b5626649c984ffa44db 100644 (file)
@@ -57,7 +57,6 @@
 #include <asm/uaccess.h>
 #include <linux/atomic.h>
 #include <linux/mutex.h>
-#include <linux/workqueue.h>
 #include <linux/cgroup.h>
 #include <linux/wait.h>
 
@@ -99,6 +98,7 @@ struct cpuset {
 
        /* user-configured CPUs and Memory Nodes allow to tasks */
        cpumask_var_t cpus_allowed;
+       cpumask_var_t cpus_requested;
        nodemask_t mems_allowed;
 
        /* effective CPUs and Memory Nodes allow to tasks */
@@ -286,6 +286,8 @@ static struct cpuset top_cpuset = {
 static DEFINE_MUTEX(cpuset_mutex);
 static DEFINE_SPINLOCK(callback_lock);
 
+static struct workqueue_struct *cpuset_migrate_mm_wq;
+
 /*
  * CPU / memory hotplug is handled asynchronously.
  */
@@ -385,7 +387,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
 
 static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
 {
-       return  cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
+       return  cpumask_subset(p->cpus_requested, q->cpus_requested) &&
                nodes_subset(p->mems_allowed, q->mems_allowed) &&
                is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
                is_mem_exclusive(p) <= is_mem_exclusive(q);
@@ -485,7 +487,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
        cpuset_for_each_child(c, css, par) {
                if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
                    c != cur &&
-                   cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
+                   cpumask_intersects(trial->cpus_requested, c->cpus_requested))
                        goto out;
                if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
                    c != cur &&
@@ -944,17 +946,18 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
        if (!*buf) {
                cpumask_clear(trialcs->cpus_allowed);
        } else {
-               retval = cpulist_parse(buf, trialcs->cpus_allowed);
+               retval = cpulist_parse(buf, trialcs->cpus_requested);
                if (retval < 0)
                        return retval;
 
-               if (!cpumask_subset(trialcs->cpus_allowed,
-                                   top_cpuset.cpus_allowed))
+               if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
                        return -EINVAL;
+
+               cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
        }
 
        /* Nothing to do if the cpus didn't change */
-       if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed))
+       if (cpumask_equal(cs->cpus_requested, trialcs->cpus_requested))
                return 0;
 
        retval = validate_change(cs, trialcs);
@@ -963,6 +966,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 
        spin_lock_irq(&callback_lock);
        cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
+       cpumask_copy(cs->cpus_requested, trialcs->cpus_requested);
        spin_unlock_irq(&callback_lock);
 
        /* use trialcs->cpus_allowed as a temp variable */
@@ -971,31 +975,51 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 }
 
 /*
- * cpuset_migrate_mm
- *
- *    Migrate memory region from one set of nodes to another.
- *
- *    Temporarilly set tasks mems_allowed to target nodes of migration,
- *    so that the migration code can allocate pages on these nodes.
- *
- *    While the mm_struct we are migrating is typically from some
- *    other task, the task_struct mems_allowed that we are hacking
- *    is for our current task, which must allocate new pages for that
- *    migrating memory region.
+ * Migrate memory region from one set of nodes to another.  This is
+ * performed asynchronously as it can be called from process migration path
+ * holding locks involved in process management.  All mm migrations are
+ * performed in the queued order and can be waited for by flushing
+ * cpuset_migrate_mm_wq.
  */
 
+struct cpuset_migrate_mm_work {
+       struct work_struct      work;
+       struct mm_struct        *mm;
+       nodemask_t              from;
+       nodemask_t              to;
+};
+
+static void cpuset_migrate_mm_workfn(struct work_struct *work)
+{
+       struct cpuset_migrate_mm_work *mwork =
+               container_of(work, struct cpuset_migrate_mm_work, work);
+
+       /* on a wq worker, no need to worry about %current's mems_allowed */
+       do_migrate_pages(mwork->mm, &mwork->from, &mwork->to, MPOL_MF_MOVE_ALL);
+       mmput(mwork->mm);
+       kfree(mwork);
+}
+
 static void cpuset_migrate_mm(struct mm_struct *mm, const nodemask_t *from,
                                                        const nodemask_t *to)
 {
-       struct task_struct *tsk = current;
-
-       tsk->mems_allowed = *to;
+       struct cpuset_migrate_mm_work *mwork;
 
-       do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL);
+       mwork = kzalloc(sizeof(*mwork), GFP_KERNEL);
+       if (mwork) {
+               mwork->mm = mm;
+               mwork->from = *from;
+               mwork->to = *to;
+               INIT_WORK(&mwork->work, cpuset_migrate_mm_workfn);
+               queue_work(cpuset_migrate_mm_wq, &mwork->work);
+       } else {
+               mmput(mm);
+       }
+}
 
-       rcu_read_lock();
-       guarantee_online_mems(task_cs(tsk), &tsk->mems_allowed);
-       rcu_read_unlock();
+static void cpuset_post_attach(void)
+{
+       flush_workqueue(cpuset_migrate_mm_wq);
 }
 
 /*
@@ -1096,7 +1120,8 @@ static void update_tasks_nodemask(struct cpuset *cs)
                mpol_rebind_mm(mm, &cs->mems_allowed);
                if (migrate)
                        cpuset_migrate_mm(mm, &cs->old_mems_allowed, &newmems);
-               mmput(mm);
+               else
+                       mmput(mm);
        }
        css_task_iter_end(&it);
 
@@ -1429,15 +1454,16 @@ static int fmeter_getrate(struct fmeter *fmp)
 static struct cpuset *cpuset_attach_old_cs;
 
 /* Called by cgroups to determine if a cpuset is usable; cpuset_mutex held */
-static int cpuset_can_attach(struct cgroup_subsys_state *css,
-                            struct cgroup_taskset *tset)
+static int cpuset_can_attach(struct cgroup_taskset *tset)
 {
-       struct cpuset *cs = css_cs(css);
+       struct cgroup_subsys_state *css;
+       struct cpuset *cs;
        struct task_struct *task;
        int ret;
 
        /* used later by cpuset_attach() */
-       cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset));
+       cpuset_attach_old_cs = task_cs(cgroup_taskset_first(tset, &css));
+       cs = css_cs(css);
 
        mutex_lock(&cpuset_mutex);
 
@@ -1447,7 +1473,7 @@ static int cpuset_can_attach(struct cgroup_subsys_state *css,
            (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)))
                goto out_unlock;
 
-       cgroup_taskset_for_each(task, tset) {
+       cgroup_taskset_for_each(task, css, tset) {
                ret = task_can_attach(task, cs->cpus_allowed);
                if (ret)
                        goto out_unlock;
@@ -1467,9 +1493,14 @@ out_unlock:
        return ret;
 }
 
-static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
-                                struct cgroup_taskset *tset)
+static void cpuset_cancel_attach(struct cgroup_taskset *tset)
 {
+       struct cgroup_subsys_state *css;
+       struct cpuset *cs;
+
+       cgroup_taskset_first(tset, &css);
+       cs = css_cs(css);
+
        mutex_lock(&cpuset_mutex);
        css_cs(css)->attach_in_progress--;
        mutex_unlock(&cpuset_mutex);
@@ -1482,16 +1513,19 @@ static void cpuset_cancel_attach(struct cgroup_subsys_state *css,
  */
 static cpumask_var_t cpus_attach;
 
-static void cpuset_attach(struct cgroup_subsys_state *css,
-                         struct cgroup_taskset *tset)
+static void cpuset_attach(struct cgroup_taskset *tset)
 {
        /* static buf protected by cpuset_mutex */
        static nodemask_t cpuset_attach_nodemask_to;
        struct task_struct *task;
        struct task_struct *leader;
-       struct cpuset *cs = css_cs(css);
+       struct cgroup_subsys_state *css;
+       struct cpuset *cs;
        struct cpuset *oldcs = cpuset_attach_old_cs;
 
+       cgroup_taskset_first(tset, &css);
+       cs = css_cs(css);
+
        mutex_lock(&cpuset_mutex);
 
        /* prepare for attach */
@@ -1502,7 +1536,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
 
        guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
 
-       cgroup_taskset_for_each(task, tset) {
+       cgroup_taskset_for_each(task, css, tset) {
                /*
                 * can_attach beforehand should guarantee that this doesn't
                 * fail.  TODO: have a better way to handle failure here
@@ -1518,7 +1552,7 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
         * sleep and should be moved outside migration path proper.
         */
        cpuset_attach_nodemask_to = cs->effective_mems;
-       cgroup_taskset_for_each_leader(leader, tset) {
+       cgroup_taskset_for_each_leader(leader, css, tset) {
                struct mm_struct *mm = get_task_mm(leader);
 
                if (mm) {
@@ -1532,11 +1566,11 @@ static void cpuset_attach(struct cgroup_subsys_state *css,
                         * @old_mems_allowed is the right nodesets that we
                         * migrate mm from.
                         */
-                       if (is_memory_migrate(cs)) {
+                       if (is_memory_migrate(cs))
                                cpuset_migrate_mm(mm, &oldcs->old_mems_allowed,
                                                  &cpuset_attach_nodemask_to);
-                       }
-                       mmput(mm);
+                       else
+                               mmput(mm);
                }
        }
 
@@ -1701,6 +1735,7 @@ out_unlock:
        mutex_unlock(&cpuset_mutex);
        kernfs_unbreak_active_protection(of->kn);
        css_put(&cs->css);
+       flush_workqueue(cpuset_migrate_mm_wq);
        return retval ?: nbytes;
 }
 
@@ -1722,7 +1757,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
 
        switch (type) {
        case FILE_CPULIST:
-               seq_printf(sf, "%*pbl\n", cpumask_pr_args(cs->cpus_allowed));
+               seq_printf(sf, "%*pbl\n", cpumask_pr_args(cs->cpus_requested));
                break;
        case FILE_MEMLIST:
                seq_printf(sf, "%*pbl\n", nodemask_pr_args(&cs->mems_allowed));
@@ -1911,11 +1946,14 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
                return ERR_PTR(-ENOMEM);
        if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL))
                goto free_cs;
+       if (!alloc_cpumask_var(&cs->cpus_requested, GFP_KERNEL))
+               goto free_allowed;
        if (!alloc_cpumask_var(&cs->effective_cpus, GFP_KERNEL))
-               goto free_cpus;
+               goto free_requested;
 
        set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
        cpumask_clear(cs->cpus_allowed);
+       cpumask_clear(cs->cpus_requested);
        nodes_clear(cs->mems_allowed);
        cpumask_clear(cs->effective_cpus);
        nodes_clear(cs->effective_mems);
@@ -1924,7 +1962,9 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 
        return &cs->css;
 
-free_cpus:
+free_requested:
+       free_cpumask_var(cs->cpus_requested);
+free_allowed:
        free_cpumask_var(cs->cpus_allowed);
 free_cs:
        kfree(cs);
@@ -1987,6 +2027,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
        cs->mems_allowed = parent->mems_allowed;
        cs->effective_mems = parent->mems_allowed;
        cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
+       cpumask_copy(cs->cpus_requested, parent->cpus_requested);
        cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
        spin_unlock_irq(&callback_lock);
 out_unlock:
@@ -2021,6 +2062,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
 
        free_cpumask_var(cs->effective_cpus);
        free_cpumask_var(cs->cpus_allowed);
+       free_cpumask_var(cs->cpus_requested);
        kfree(cs);
 }
 
@@ -2042,14 +2084,33 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
        mutex_unlock(&cpuset_mutex);
 }
 
+static int cpuset_allow_attach(struct cgroup_taskset *tset)
+{
+       const struct cred *cred = current_cred(), *tcred;
+       struct task_struct *task;
+       struct cgroup_subsys_state *css;
+
+       cgroup_taskset_for_each(task, css, tset) {
+               tcred = __task_cred(task);
+
+               if ((current != task) && !capable(CAP_SYS_ADMIN) &&
+                    cred->euid.val != tcred->uid.val && cred->euid.val != tcred->suid.val)
+                       return -EACCES;
+       }
+
+       return 0;
+}
+
 struct cgroup_subsys cpuset_cgrp_subsys = {
        .css_alloc      = cpuset_css_alloc,
        .css_online     = cpuset_css_online,
        .css_offline    = cpuset_css_offline,
        .css_free       = cpuset_css_free,
        .can_attach     = cpuset_can_attach,
+       .allow_attach   = cpuset_allow_attach,
        .cancel_attach  = cpuset_cancel_attach,
        .attach         = cpuset_attach,
+       .post_attach    = cpuset_post_attach,
        .bind           = cpuset_bind,
        .legacy_cftypes = files,
        .early_init     = 1,
@@ -2069,8 +2130,11 @@ int __init cpuset_init(void)
                BUG();
        if (!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL))
                BUG();
+       if (!alloc_cpumask_var(&top_cpuset.cpus_requested, GFP_KERNEL))
+               BUG();
 
        cpumask_setall(top_cpuset.cpus_allowed);
+       cpumask_setall(top_cpuset.cpus_requested);
        nodes_setall(top_cpuset.mems_allowed);
        cpumask_setall(top_cpuset.effective_cpus);
        nodes_setall(top_cpuset.effective_mems);
@@ -2204,7 +2268,7 @@ retry:
                goto retry;
        }
 
-       cpumask_and(&new_cpus, cs->cpus_allowed, parent_cs(cs)->effective_cpus);
+       cpumask_and(&new_cpus, cs->cpus_requested, parent_cs(cs)->effective_cpus);
        nodes_and(new_mems, cs->mems_allowed, parent_cs(cs)->effective_mems);
 
        cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus);
@@ -2346,6 +2410,9 @@ void __init cpuset_init_smp(void)
        top_cpuset.effective_mems = node_states[N_MEMORY];
 
        register_hotmemory_notifier(&cpuset_track_online_nodes_nb);
+
+       cpuset_migrate_mm_wq = alloc_ordered_workqueue("cpuset_migrate_mm", 0);
+       BUG_ON(!cpuset_migrate_mm_wq);
 }
 
 /**