[SCSI] zfcp: Remove busid macro
[safe/jmp/linux-2.6] / kernel / sched.c
index ebaf432..748ff92 100644 (file)
  */
 #define RUNTIME_INF    ((u64)~0ULL)
 
+DEFINE_TRACE(sched_wait_task);
+DEFINE_TRACE(sched_wakeup);
+DEFINE_TRACE(sched_wakeup_new);
+DEFINE_TRACE(sched_switch);
+DEFINE_TRACE(sched_migrate_task);
+
 #ifdef CONFIG_SMP
 /*
  * Divide a load by a sched group cpu_power : (load / sg->__cpu_power)
@@ -261,6 +267,10 @@ struct task_group {
        struct cgroup_subsys_state css;
 #endif
 
+#ifdef CONFIG_USER_SCHED
+       uid_t uid;
+#endif
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
        /* schedulable entities of this group on each cpu */
        struct sched_entity **se;
@@ -286,6 +296,12 @@ struct task_group {
 
 #ifdef CONFIG_USER_SCHED
 
+/* Helper function to pass uid information to create_sched_user() */
+void set_tg_uid(struct user_struct *user)
+{
+       user->tg->uid = user->uid;
+}
+
 /*
  * Root task group.
  *     Every UID task group (including init_task_group aka UID-0) will
@@ -345,7 +361,9 @@ static inline struct task_group *task_group(struct task_struct *p)
        struct task_group *tg;
 
 #ifdef CONFIG_USER_SCHED
-       tg = p->user->tg;
+       rcu_read_lock();
+       tg = __task_cred(p)->user->tg;
+       rcu_read_unlock();
 #elif defined(CONFIG_CGROUP_SCHED)
        tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id),
                                struct task_group, css);
@@ -399,7 +417,7 @@ struct cfs_rq {
         */
        struct sched_entity *curr, *next, *last;
 
-       unsigned long nr_spread_over;
+       unsigned int nr_spread_over;
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
        struct rq *rq;  /* cpu runqueue to which this cfs_rq is attached */
@@ -586,6 +604,8 @@ struct rq {
 #ifdef CONFIG_SCHEDSTATS
        /* latency stats */
        struct sched_info rq_sched_info;
+       unsigned long long rq_cpu_time;
+       /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
 
        /* sys_sched_yield() stats */
        unsigned int yld_exp_empty;
@@ -949,6 +969,14 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
        }
 }
 
+void task_rq_unlock_wait(struct task_struct *p)
+{
+       struct rq *rq = task_rq(p);
+
+       smp_mb(); /* spin-unlock-wait is not a full memory barrier */
+       spin_unlock_wait(&rq->lock);
+}
+
 static void __task_rq_unlock(struct rq *rq)
        __releases(rq->lock)
 {
@@ -1425,9 +1453,12 @@ static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
 static unsigned long cpu_avg_load_per_task(int cpu)
 {
        struct rq *rq = cpu_rq(cpu);
+       unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
 
-       if (rq->nr_running)
-               rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+       if (nr_running)
+               rq->avg_load_per_task = rq->load.weight / nr_running;
+       else
+               rq->avg_load_per_task = 0;
 
        return rq->avg_load_per_task;
 }
@@ -1443,27 +1474,13 @@ static void
 update_group_shares_cpu(struct task_group *tg, int cpu,
                        unsigned long sd_shares, unsigned long sd_rq_weight)
 {
-       int boost = 0;
        unsigned long shares;
        unsigned long rq_weight;
 
        if (!tg->se[cpu])
                return;
 
-       rq_weight = tg->cfs_rq[cpu]->load.weight;
-
-       /*
-        * If there are currently no tasks on the cpu pretend there is one of
-        * average load so that when a new task gets to run here it will not
-        * get delayed by group starvation.
-        */
-       if (!rq_weight) {
-               boost = 1;
-               rq_weight = NICE_0_LOAD;
-       }
-
-       if (unlikely(rq_weight > sd_rq_weight))
-               rq_weight = sd_rq_weight;
+       rq_weight = tg->cfs_rq[cpu]->rq_weight;
 
        /*
         *           \Sum shares * rq_weight
@@ -1471,7 +1488,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
         *               \Sum rq_weight
         *
         */
-       shares = (sd_shares * rq_weight) / (sd_rq_weight + 1);
+       shares = (sd_shares * rq_weight) / sd_rq_weight;
        shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES);
 
        if (abs(shares - tg->se[cpu]->load.weight) >
@@ -1480,11 +1497,7 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
                unsigned long flags;
 
                spin_lock_irqsave(&rq->lock, flags);
-               /*
-                * record the actual number of shares, not the boosted amount.
-                */
-               tg->cfs_rq[cpu]->shares = boost ? 0 : shares;
-               tg->cfs_rq[cpu]->rq_weight = rq_weight;
+               tg->cfs_rq[cpu]->shares = shares;
 
                __set_se_shares(tg->se[cpu], shares);
                spin_unlock_irqrestore(&rq->lock, flags);
@@ -1498,13 +1511,23 @@ update_group_shares_cpu(struct task_group *tg, int cpu,
  */
 static int tg_shares_up(struct task_group *tg, void *data)
 {
-       unsigned long rq_weight = 0;
+       unsigned long weight, rq_weight = 0;
        unsigned long shares = 0;
        struct sched_domain *sd = data;
        int i;
 
        for_each_cpu_mask(i, sd->span) {
-               rq_weight += tg->cfs_rq[i]->load.weight;
+               /*
+                * If there are currently no tasks on the cpu pretend there
+                * is one of average load so that when a new task gets to
+                * run here it will not get delayed by group starvation.
+                */
+               weight = tg->cfs_rq[i]->load.weight;
+               if (!weight)
+                       weight = NICE_0_LOAD;
+
+               tg->cfs_rq[i]->rq_weight = weight;
+               rq_weight += weight;
                shares += tg->cfs_rq[i]->shares;
        }
 
@@ -1514,9 +1537,6 @@ static int tg_shares_up(struct task_group *tg, void *data)
        if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE))
                shares = tg->shares;
 
-       if (!rq_weight)
-               rq_weight = cpus_weight(sd->span) * NICE_0_LOAD;
-
        for_each_cpu_mask(i, sd->span)
                update_group_shares_cpu(tg, i, shares, rq_weight);
 
@@ -1581,6 +1601,39 @@ static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd)
 
 #endif
 
+/*
+ * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
+ */
+static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
+       __releases(this_rq->lock)
+       __acquires(busiest->lock)
+       __acquires(this_rq->lock)
+{
+       int ret = 0;
+
+       if (unlikely(!irqs_disabled())) {
+               /* printk() doesn't work good under rq->lock */
+               spin_unlock(&this_rq->lock);
+               BUG_ON(1);
+       }
+       if (unlikely(!spin_trylock(&busiest->lock))) {
+               if (busiest < this_rq) {
+                       spin_unlock(&this_rq->lock);
+                       spin_lock(&busiest->lock);
+                       spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
+                       ret = 1;
+               } else
+                       spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
+       }
+       return ret;
+}
+
+static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
+       __releases(busiest->lock)
+{
+       spin_unlock(&busiest->lock);
+       lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
+}
 #endif
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
@@ -1814,6 +1867,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 
        clock_offset = old_rq->clock - new_rq->clock;
 
+       trace_sched_migrate_task(p, task_cpu(p), new_cpu);
+
 #ifdef CONFIG_SCHEDSTATS
        if (p->se.wait_start)
                p->se.wait_start -= clock_offset;
@@ -2223,6 +2278,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 
        smp_wmb();
        rq = task_rq_lock(p, &flags);
+       update_rq_clock(rq);
        old_state = p->state;
        if (!(old_state & state))
                goto out;
@@ -2280,12 +2336,11 @@ out_activate:
                schedstat_inc(p, se.nr_wakeups_local);
        else
                schedstat_inc(p, se.nr_wakeups_remote);
-       update_rq_clock(rq);
        activate_task(rq, p, 1);
        success = 1;
 
 out_running:
-       trace_sched_wakeup(rq, p);
+       trace_sched_wakeup(rq, p, success);
        check_preempt_curr(rq, p, sync);
 
        p->state = TASK_RUNNING;
@@ -2418,7 +2473,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
                p->sched_class->task_new(rq, p);
                inc_nr_running(rq);
        }
-       trace_sched_wakeup_new(rq, p);
+       trace_sched_wakeup_new(rq, p, 1);
        check_preempt_curr(rq, p, 0);
 #ifdef CONFIG_SMP
        if (p->sched_class->task_wake_up)
@@ -2781,40 +2836,6 @@ static void double_rq_unlock(struct rq *rq1, struct rq *rq2)
 }
 
 /*
- * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
- */
-static int double_lock_balance(struct rq *this_rq, struct rq *busiest)
-       __releases(this_rq->lock)
-       __acquires(busiest->lock)
-       __acquires(this_rq->lock)
-{
-       int ret = 0;
-
-       if (unlikely(!irqs_disabled())) {
-               /* printk() doesn't work good under rq->lock */
-               spin_unlock(&this_rq->lock);
-               BUG_ON(1);
-       }
-       if (unlikely(!spin_trylock(&busiest->lock))) {
-               if (busiest < this_rq) {
-                       spin_unlock(&this_rq->lock);
-                       spin_lock(&busiest->lock);
-                       spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING);
-                       ret = 1;
-               } else
-                       spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING);
-       }
-       return ret;
-}
-
-static void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
-       __releases(busiest->lock)
-{
-       spin_unlock(&busiest->lock);
-       lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
-}
-
-/*
  * If dest_cpu is allowed for this process, migrate the task to it.
  * This is accomplished by forcing the cpu_allowed mask to only
  * allow dest_cpu, which will force the cpu onto dest_cpu. Then
@@ -2831,7 +2852,6 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu)
            || unlikely(!cpu_active(dest_cpu)))
                goto out;
 
-       trace_sched_migrate_task(rq, p, dest_cpu);
        /* force the process onto the specified CPU */
        if (migrate_task(p, dest_cpu, &req)) {
                /* Need to wait for migration thread (might exit: take ref). */
@@ -3676,7 +3696,7 @@ out_balanced:
 static void idle_balance(int this_cpu, struct rq *this_rq)
 {
        struct sched_domain *sd;
-       int pulled_task = -1;
+       int pulled_task = 0;
        unsigned long next_balance = jiffies + HZ;
        cpumask_t tmpmask;
 
@@ -5103,6 +5123,22 @@ __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio)
        set_load_weight(p);
 }
 
+/*
+ * check the target process has a UID that matches the current process's
+ */
+static bool check_same_owner(struct task_struct *p)
+{
+       const struct cred *cred = current_cred(), *pcred;
+       bool match;
+
+       rcu_read_lock();
+       pcred = __task_cred(p);
+       match = (cred->euid == pcred->euid ||
+                cred->euid == pcred->uid);
+       rcu_read_unlock();
+       return match;
+}
+
 static int __sched_setscheduler(struct task_struct *p, int policy,
                                struct sched_param *param, bool user)
 {
@@ -5162,8 +5198,7 @@ recheck:
                        return -EPERM;
 
                /* can't change other user's priorities */
-               if ((current->euid != p->euid) &&
-                   (current->euid != p->uid))
+               if (!check_same_owner(p))
                        return -EPERM;
        }
 
@@ -5395,8 +5430,7 @@ long sched_setaffinity(pid_t pid, const cpumask_t *in_mask)
        read_unlock(&tasklist_lock);
 
        retval = -EPERM;
-       if ((current->euid != p->euid) && (current->euid != p->uid) &&
-                       !capable(CAP_SYS_NICE))
+       if (!check_same_owner(p) && !capable(CAP_SYS_NICE))
                goto out_unlock;
 
        retval = security_task_setscheduler(p, 0, NULL);
@@ -5840,6 +5874,8 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
        struct rq *rq = cpu_rq(cpu);
        unsigned long flags;
 
+       spin_lock_irqsave(&rq->lock, flags);
+
        __sched_fork(idle);
        idle->se.exec_start = sched_clock();
 
@@ -5847,7 +5883,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
        idle->cpus_allowed = cpumask_of_cpu(cpu);
        __set_task_cpu(idle, cpu);
 
-       spin_lock_irqsave(&rq->lock, flags);
        rq->curr = rq->idle = idle;
 #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)
        idle->oncpu = 1;
@@ -5864,6 +5899,7 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
         * The idle tasks have their own, simple scheduling class:
         */
        idle->sched_class = &idle_sched_class;
+       ftrace_graph_init_task(idle);
 }
 
 /*
@@ -6094,7 +6130,6 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu)
 
 /*
  * Figure out where task on dead CPU should go, use force if necessary.
- * NOTE: interrupts should be disabled by the caller
  */
 static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
 {
@@ -6555,7 +6590,9 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                        req = list_entry(rq->migration_queue.next,
                                         struct migration_req, list);
                        list_del_init(&req->list);
+                       spin_unlock_irq(&rq->lock);
                        complete(&req->done);
+                       spin_lock_irq(&rq->lock);
                }
                spin_unlock_irq(&rq->lock);
                break;
@@ -6759,6 +6796,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
                                SD_BALANCE_EXEC |
                                SD_SHARE_CPUPOWER |
                                SD_SHARE_PKG_RESOURCES);
+               if (nr_node_ids == 1)
+                       pflags &= ~SD_SERIALIZE;
        }
        if (~cflags & pflags)
                return 0;
@@ -7662,8 +7701,14 @@ static struct sched_domain_attr *dattr_cur;
  */
 static cpumask_t fallback_doms;
 
-void __attribute__((weak)) arch_update_cpu_topology(void)
+/*
+ * arch_update_cpu_topology lets virtualized architectures update the
+ * cpu core maps. It is supposed to return 1 if the topology changed
+ * or 0 if it stayed the same.
+ */
+int __attribute__((weak)) arch_update_cpu_topology(void)
 {
+       return 0;
 }
 
 /*
@@ -7740,13 +7785,14 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur,
  *
  * The passed in 'doms_new' should be kmalloc'd. This routine takes
  * ownership of it and will kfree it when done with it. If the caller
- * failed the kmalloc call, then it can pass in doms_new == NULL,
- * and partition_sched_domains() will fallback to the single partition
- * 'fallback_doms', it also forces the domains to be rebuilt.
+ * failed the kmalloc call, then it can pass in doms_new == NULL &&
+ * ndoms_new == 1, and partition_sched_domains() will fallback to
+ * the single partition 'fallback_doms', it also forces the domains
+ * to be rebuilt.
  *
- * If doms_new==NULL it will be replaced with cpu_online_map.
- * ndoms_new==0 is a special case for destroying existing domains.
- * It will not create the default domain.
+ * If doms_new == NULL it will be replaced with cpu_online_map.
+ * ndoms_new == 0 is a special case for destroying existing domains,
+ * and it will not create the default domain.
  *
  * Call with hotplug lock held
  */
@@ -7754,17 +7800,21 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
                             struct sched_domain_attr *dattr_new)
 {
        int i, j, n;
+       int new_topology;
 
        mutex_lock(&sched_domains_mutex);
 
        /* always unregister in case we don't destroy any domains */
        unregister_sched_domain_sysctl();
 
+       /* Let architecture update cpu core mappings. */
+       new_topology = arch_update_cpu_topology();
+
        n = doms_new ? ndoms_new : 0;
 
        /* Destroy deleted domains */
        for (i = 0; i < ndoms_cur; i++) {
-               for (j = 0; j < n; j++) {
+               for (j = 0; j < n && !new_topology; j++) {
                        if (cpus_equal(doms_cur[i], doms_new[j])
                            && dattrs_equal(dattr_cur, i, dattr_new, j))
                                goto match1;
@@ -7784,7 +7834,7 @@ match1:
 
        /* Build new domains */
        for (i = 0; i < ndoms_new; i++) {
-               for (j = 0; j < ndoms_cur; j++) {
+               for (j = 0; j < ndoms_cur && !new_topology; j++) {
                        if (cpus_equal(doms_new[i], doms_cur[j])
                            && dattrs_equal(dattr_new, i, dattr_cur, j))
                                goto match2;
@@ -9251,6 +9301,41 @@ cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp)
        kfree(ca);
 }
 
+static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu)
+{
+       u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+       u64 data;
+
+#ifndef CONFIG_64BIT
+       /*
+        * Take rq->lock to make 64-bit read safe on 32-bit platforms.
+        */
+       spin_lock_irq(&cpu_rq(cpu)->lock);
+       data = *cpuusage;
+       spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+       data = *cpuusage;
+#endif
+
+       return data;
+}
+
+static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val)
+{
+       u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu);
+
+#ifndef CONFIG_64BIT
+       /*
+        * Take rq->lock to make 64-bit write safe on 32-bit platforms.
+        */
+       spin_lock_irq(&cpu_rq(cpu)->lock);
+       *cpuusage = val;
+       spin_unlock_irq(&cpu_rq(cpu)->lock);
+#else
+       *cpuusage = val;
+#endif
+}
+
 /* return total cpu usage (in nanoseconds) of a group */
 static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
 {
@@ -9258,17 +9343,8 @@ static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft)
        u64 totalcpuusage = 0;
        int i;
 
-       for_each_possible_cpu(i) {
-               u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
-
-               /*
-                * Take rq->lock to make 64-bit addition safe on 32-bit
-                * platforms.
-                */
-               spin_lock_irq(&cpu_rq(i)->lock);
-               totalcpuusage += *cpuusage;
-               spin_unlock_irq(&cpu_rq(i)->lock);
-       }
+       for_each_present_cpu(i)
+               totalcpuusage += cpuacct_cpuusage_read(ca, i);
 
        return totalcpuusage;
 }
@@ -9285,23 +9361,39 @@ static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
                goto out;
        }
 
-       for_each_possible_cpu(i) {
-               u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
+       for_each_present_cpu(i)
+               cpuacct_cpuusage_write(ca, i, 0);
 
-               spin_lock_irq(&cpu_rq(i)->lock);
-               *cpuusage = 0;
-               spin_unlock_irq(&cpu_rq(i)->lock);
-       }
 out:
        return err;
 }
 
+static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
+                                  struct seq_file *m)
+{
+       struct cpuacct *ca = cgroup_ca(cgroup);
+       u64 percpu;
+       int i;
+
+       for_each_present_cpu(i) {
+               percpu = cpuacct_cpuusage_read(ca, i);
+               seq_printf(m, "%llu ", (unsigned long long) percpu);
+       }
+       seq_printf(m, "\n");
+       return 0;
+}
+
 static struct cftype files[] = {
        {
                .name = "usage",
                .read_u64 = cpuusage_read,
                .write_u64 = cpuusage_write,
        },
+       {
+               .name = "usage_percpu",
+               .read_seq_string = cpuacct_percpu_seq_read,
+       },
+
 };
 
 static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)