Merge branch 'sched/urgent' into sched/core

Merge reason: Pick up fixes that did not make it into .32.0

Signed-off-by: Ingo Molnar <mingo@elte.hu>

23 files changed, 373 insertions, 193 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index ca83b73fba19..0249f4be9b5c 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1710,14 +1710,13 @@ static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
                 return -EFAULT;
 
         buffer[nbytes] = 0;     /* nul-terminate */
-        strstrip(buffer);
         if (cft->write_u64) {
-                u64 val = simple_strtoull(buffer, &end, 0);
+                u64 val = simple_strtoull(strstrip(buffer), &end, 0);
                 if (*end)
                         return -EINVAL;
                 retval = cft->write_u64(cgrp, cft, val);
         } else {
-                s64 val = simple_strtoll(buffer, &end, 0);
+                s64 val = simple_strtoll(strstrip(buffer), &end, 0);
                 if (*end)
                         return -EINVAL;
                 retval = cft->write_s64(cgrp, cft, val);
@@ -1753,8 +1752,7 @@ static ssize_t cgroup_write_string(struct cgroup *cgrp, struct cftype *cft,
         }
 
         buffer[nbytes] = 0;     /* nul-terminate */
-        strstrip(buffer);
-        retval = cft->write_string(cgrp, cft, buffer);
+        retval = cft->write_string(cgrp, cft, strstrip(buffer));
         if (!retval)
                 retval = nbytes;
 out:
diff --git a/kernel/exit.c b/kernel/exit.c
index e61891f80123..f7864ac2ecc1 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -359,10 +359,8 @@ void __set_special_pids(struct pid *pid)
 {
         struct task_struct *curr = current->group_leader;
 
-        if (task_session(curr) != pid) {
+        if (task_session(curr) != pid)
                 change_pid(curr, PIDTYPE_SID, pid);
-                proc_sid_connector(curr);
-        }
 
         if (task_pgrp(curr) != pid)
                 change_pid(curr, PIDTYPE_PGID, pid);
diff --git a/kernel/fork.c b/kernel/fork.c
index 4c20fff8c13a..166b8c49257c 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -91,7 +91,7 @@ int nr_processes(void)
         int cpu;
         int total = 0;
 
-        for_each_online_cpu(cpu)
+        for_each_possible_cpu(cpu)
                 total += per_cpu(process_counts, cpu);
 
         return total;
diff --git a/kernel/futex.c b/kernel/futex.c
index 4949d336d88d..fb65e822fc41 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -150,7 +150,8 @@ static struct futex_hash_bucket *hash_futex(union futex_key *key)
  */
 static inline int match_futex(union futex_key *key1, union futex_key *key2)
 {
-        return (key1->both.word == key2->both.word
+        return (key1 && key2
+                && key1->both.word == key2->both.word
                 && key1->both.ptr == key2->both.ptr
                 && key1->both.offset == key2->both.offset);
 }
@@ -1028,7 +1029,6 @@ static inline
 void requeue_pi_wake_futex(struct futex_q *q, union futex_key *key,
                            struct futex_hash_bucket *hb)
 {
-        drop_futex_key_refs(&q->key);
         get_futex_key_refs(key);
         q->key = *key;
 
@@ -1226,6 +1226,7 @@ retry_private:
                  */
                 if (ret == 1) {
                         WARN_ON(pi_state);
+                        drop_count++;
                         task_count++;
                         ret = get_futex_value_locked(&curval2, uaddr2);
                         if (!ret)
@@ -1304,6 +1305,7 @@ retry_private:
                         if (ret == 1) {
                                 /* We got the lock. */
                                 requeue_pi_wake_futex(this, &key2, hb2);
+                                drop_count++;
                                 continue;
                         } else if (ret) {
                                 /* -EDEADLK */
@@ -1791,6 +1793,7 @@ static int futex_wait(u32 __user *uaddr, int fshared,
                                              current->timer_slack_ns);
         }
 
+retry:
         /* Prepare to wait on uaddr. */
         ret = futex_wait_setup(uaddr, val, fshared, &q, &hb);
         if (ret)
@@ -1808,9 +1811,14 @@ static int futex_wait(u32 __user *uaddr, int fshared,
                 goto out_put_key;
 
         /*
-         * We expect signal_pending(current), but another thread may
-         * have handled it for us already.
+         * We expect signal_pending(current), but we might be the
+         * victim of a spurious wakeup as well.
          */
+        if (!signal_pending(current)) {
+                put_futex_key(fshared, &q.key);
+                goto retry;
+        }
+
         ret = -ERESTARTSYS;
         if (!abs_time)
                 goto out_put_key;
@@ -2118,9 +2126,11 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
                  */
                 plist_del(&q->list, &q->list.plist);
 
+                /* Handle spurious wakeups gracefully */
+                ret = -EWOULDBLOCK;
                 if (timeout && !timeout->task)
                         ret = -ETIMEDOUT;
-                else
+                else if (signal_pending(current))
                         ret = -ERESTARTNOINTR;
         }
         return ret;
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 114e704760fe..bd7273e6282e 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -121,7 +121,9 @@ static void poll_all_shared_irqs(void)
                 if (!(status & IRQ_SPURIOUS_DISABLED))
                         continue;
 
+                local_irq_disable();
                 try_one_irq(i, desc);
+                local_irq_enable();
         }
 }
 
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 5fe709982caa..ab7ae57773e1 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -150,29 +150,6 @@ struct task_struct *kthread_create(int (*threadfn)(void *data),
 EXPORT_SYMBOL(kthread_create);
 
 /**
- * kthread_bind - bind a just-created kthread to a cpu.
- * @k: thread created by kthread_create().
- * @cpu: cpu (might not be online, must be possible) for @k to run on.
- *
- * Description: This function is equivalent to set_cpus_allowed(),
- * except that @cpu doesn't need to be online, and the thread must be
- * stopped (i.e., just returned from kthread_create()).
- */
-void kthread_bind(struct task_struct *k, unsigned int cpu)
-{
-        /* Must have done schedule() in kthread() before we set_task_cpu */
-        if (!wait_task_inactive(k, TASK_UNINTERRUPTIBLE)) {
-                WARN_ON(1);
-                return;
-        }
-        set_task_cpu(k, cpu);
-        k->cpus_allowed = cpumask_of_cpu(cpu);
-        k->rt.nr_cpus_allowed = 1;
-        k->flags |= PF_THREAD_BOUND;
-}
-EXPORT_SYMBOL(kthread_bind);
-
-/**
  * kthread_stop - stop a thread created by kthread_create().
  * @k: thread created by kthread_create().
  *
diff --git a/kernel/params.c b/kernel/params.c
index 9da58eabdcb2..d656c276508d 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -218,15 +218,11 @@ int param_set_charp(const char *val, struct kernel_param *kp)
                 return -ENOSPC;
         }
 
-        if (kp->flags & KPARAM_KMALLOCED)
-                kfree(*(char **)kp->arg);
-
         /* This is a hack.  We can't need to strdup in early boot, and we
          * don't need to; this mangled commandline is preserved. */
         if (slab_is_available()) {
-                kp->flags |= KPARAM_KMALLOCED;
                 *(char **)kp->arg = kstrdup(val, GFP_KERNEL);
-                if (!kp->arg)
+                if (!*(char **)kp->arg)
                         return -ENOMEM;
         } else
                 *(const char **)kp->arg = val;
@@ -304,6 +300,7 @@ static int param_array(const char *name,
                        unsigned int min, unsigned int max,
                        void *elem, int elemsize,
                        int (*set)(const char *, struct kernel_param *kp),
+                       u16 flags,
                        unsigned int *num)
 {
         int ret;
@@ -313,6 +310,7 @@ static int param_array(const char *name,
         /* Get the name right for errors. */
         kp.name = name;
         kp.arg = elem;
+        kp.flags = flags;
 
         /* No equals sign? */
         if (!val) {
@@ -358,7 +356,8 @@ int param_array_set(const char *val, struct kernel_param *kp)
         unsigned int temp_num;
 
         return param_array(kp->name, val, 1, arr->max, arr->elem,
-                           arr->elemsize, arr->set, arr->num ?: &temp_num);
+                           arr->elemsize, arr->set, kp->flags,
+                           arr->num ?: &temp_num);
 }
 
 int param_array_get(char *buffer, struct kernel_param *kp)
@@ -605,11 +604,7 @@ void module_param_sysfs_remove(struct module *mod)
 
 void destroy_params(const struct kernel_param *params, unsigned num)
 {
-        unsigned int i;
-
-        for (i = 0; i < num; i++)
-                if (params[i].flags & KPARAM_KMALLOCED)
-                        kfree(*(char **)params[i].arg);
+        /* FIXME: This should free kmalloced charp parameters.  It doesn't. */
 }
 
 static void __init kernel_add_sysfs_param(const char *name,
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 9d0b5c665883..7f29643c8985 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1355,7 +1355,7 @@ static void perf_ctx_adjust_freq(struct perf_event_context *ctx)
         u64 interrupts, freq;
 
         spin_lock(&ctx->lock);
-        list_for_each_entry(event, &ctx->group_list, group_entry) {
+        list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (event->state != PERF_EVENT_STATE_ACTIVE)
                         continue;
 
@@ -3959,8 +3959,9 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
                 regs = task_pt_regs(current);
 
         if (regs) {
-                if (perf_event_overflow(event, 0, &data, regs))
-                        ret = HRTIMER_NORESTART;
+                if (!(event->attr.exclude_idle && current->pid == 0))
+                        if (perf_event_overflow(event, 0, &data, regs))
+                                ret = HRTIMER_NORESTART;
         }
 
         period = max_t(u64, 10000, event->hw.sample_period);
@@ -3969,6 +3970,42 @@ static enum hrtimer_restart perf_swevent_hrtimer(struct hrtimer *hrtimer)
         return ret;
 }
 
+static void perf_swevent_start_hrtimer(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        hwc->hrtimer.function = perf_swevent_hrtimer;
+        if (hwc->sample_period) {
+                u64 period;
+
+                if (hwc->remaining) {
+                        if (hwc->remaining < 0)
+                                period = 10000;
+                        else
+                                period = hwc->remaining;
+                        hwc->remaining = 0;
+                } else {
+                        period = max_t(u64, 10000, hwc->sample_period);
+                }
+                __hrtimer_start_range_ns(&hwc->hrtimer,
+                                ns_to_ktime(period), 0,
+                                HRTIMER_MODE_REL, 0);
+        }
+}
+
+static void perf_swevent_cancel_hrtimer(struct perf_event *event)
+{
+        struct hw_perf_event *hwc = &event->hw;
+
+        if (hwc->sample_period) {
+                ktime_t remaining = hrtimer_get_remaining(&hwc->hrtimer);
+                hwc->remaining = ktime_to_ns(remaining);
+
+                hrtimer_cancel(&hwc->hrtimer);
+        }
+}
+
 /*
  * Software event: cpu wall time clock
  */
@@ -3991,22 +4028,14 @@ static int cpu_clock_perf_event_enable(struct perf_event *event)
         int cpu = raw_smp_processor_id();
 
         atomic64_set(&hwc->prev_count, cpu_clock(cpu));
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swevent_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
+        perf_swevent_start_hrtimer(event);
 
         return 0;
 }
 
 static void cpu_clock_perf_event_disable(struct perf_event *event)
 {
-        if (event->hw.sample_period)
-                hrtimer_cancel(&event->hw.hrtimer);
+        perf_swevent_cancel_hrtimer(event);
         cpu_clock_perf_event_update(event);
 }
 
@@ -4043,22 +4072,15 @@ static int task_clock_perf_event_enable(struct perf_event *event)
         now = event->ctx->time;
 
         atomic64_set(&hwc->prev_count, now);
-        hrtimer_init(&hwc->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-        hwc->hrtimer.function = perf_swevent_hrtimer;
-        if (hwc->sample_period) {
-                u64 period = max_t(u64, 10000, hwc->sample_period);
-                __hrtimer_start_range_ns(&hwc->hrtimer,
-                                ns_to_ktime(period), 0,
-                                HRTIMER_MODE_REL, 0);
-        }
+
+        perf_swevent_start_hrtimer(event);
 
         return 0;
 }
 
 static void task_clock_perf_event_disable(struct perf_event *event)
 {
-        if (event->hw.sample_period)
-                hrtimer_cancel(&event->hw.hrtimer);
+        perf_swevent_cancel_hrtimer(event);
         task_clock_perf_event_update(event, event->ctx->time);
 
 }
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 04b3a83d686f..04a9e90d248f 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -693,21 +693,22 @@ static int software_resume(void)
         /* The snapshot device should not be opened while we're running */
         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
                 error = -EBUSY;
+                swsusp_close(FMODE_READ);
                 goto Unlock;
         }
 
         pm_prepare_console();
         error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
         if (error)
-                goto Finish;
+                goto close_finish;
 
         error = usermodehelper_disable();
         if (error)
-                goto Finish;
+                goto close_finish;
 
         error = create_basic_memory_bitmaps();
         if (error)
-                goto Finish;
+                goto close_finish;
 
         pr_debug("PM: Preparing processes for restore.\n");
         error = prepare_processes();
@@ -719,6 +720,7 @@ static int software_resume(void)
         pr_debug("PM: Reading hibernation image.\n");
 
         error = swsusp_read(&flags);
+        swsusp_close(FMODE_READ);
         if (!error)
                 hibernation_restore(flags & SF_PLATFORM_MODE);
 
@@ -737,6 +739,9 @@ static int software_resume(void)
         mutex_unlock(&pm_mutex);
         pr_debug("PM: Resume from disk failed.\n");
         return error;
+close_finish:
+        swsusp_close(FMODE_READ);
+        goto Finish;
 }
 
 late_initcall(software_resume);
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index b101cdc4df3f..890f6b11b1d3 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -314,7 +314,6 @@ static int save_image(struct swap_map_handle *handle,
 {
         unsigned int m;
         int ret;
-        int error = 0;
         int nr_pages;
         int err2;
         struct bio *bio;
@@ -329,26 +328,27 @@ static int save_image(struct swap_map_handle *handle,
         nr_pages = 0;
         bio = NULL;
         do_gettimeofday(&start);
-        do {
+        while (1) {
                 ret = snapshot_read_next(snapshot, PAGE_SIZE);
-                if (ret > 0) {
-                        error = swap_write_page(handle, data_of(*snapshot),
-                                                &bio);
-                        if (error)
-                                break;
-                        if (!(nr_pages % m))
-                                printk("\b\b\b\b%3d%%", nr_pages / m);
-                        nr_pages++;
-                }
-        } while (ret > 0);
+                if (ret <= 0)
+                        break;
+                ret = swap_write_page(handle, data_of(*snapshot), &bio);
+                if (ret)
+                        break;
+                if (!(nr_pages % m))
+                        printk("\b\b\b\b%3d%%", nr_pages / m);
+                nr_pages++;
+        }
         err2 = wait_on_bio_chain(&bio);
         do_gettimeofday(&stop);
-        if (!error)
-                error = err2;
-        if (!error)
+        if (!ret)
+                ret = err2;
+        if (!ret)
                 printk("\b\b\b\bdone\n");
+        else
+                printk("\n");
         swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
-        return error;
+        return ret;
 }
 
 /**
@@ -536,7 +536,8 @@ static int load_image(struct swap_map_handle *handle,
                 snapshot_write_finalize(snapshot);
                 if (!snapshot_image_loaded(snapshot))
                         error = -ENODATA;
-        }
+        } else
+                printk("\n");
         swsusp_show_speed(&start, &stop, nr_to_read, "Read");
         return error;
 }
@@ -572,8 +573,6 @@ int swsusp_read(unsigned int *flags_p)
                 error = load_image(&handle, &snapshot, header->pages - 1);
         release_swap_reader(&handle);
 
-        blkdev_put(resume_bdev, FMODE_READ);
-
         if (!error)
                 pr_debug("PM: Image successfully loaded\n");
         else
@@ -596,7 +595,7 @@ int swsusp_check(void)
                 error = bio_read_page(swsusp_resume_block,
                                         swsusp_header, NULL);
                 if (error)
-                        return error;
+                        goto put;
 
                 if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) {
                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
@@ -604,8 +603,10 @@ int swsusp_check(void)
                         error = bio_write_page(swsusp_resume_block,
                                                 swsusp_header, NULL);
                 } else {
-                        return -EINVAL;
+                        error = -EINVAL;
                 }
+
+put:
                 if (error)
                         blkdev_put(resume_bdev, FMODE_READ);
                 else
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 705f02ac7433..f3077c0ab181 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -59,7 +59,7 @@
                 NUM_RCU_LVL_2, \
                 NUM_RCU_LVL_3, /* == MAX_RCU_LVLS */ \
         }, \
-        .signaled = RCU_SIGNAL_INIT, \
+        .signaled = RCU_GP_IDLE, \
         .gpnum = -300, \
         .completed = -300, \
         .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
@@ -657,14 +657,17 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
          * irqs disabled.
          */
         rcu_for_each_node_breadth_first(rsp, rnp) {
-                spin_lock(&rnp->lock);  /* irqs already disabled. */
+                spin_lock(&rnp->lock);          /* irqs already disabled. */
                 rcu_preempt_check_blocked_tasks(rnp);
                 rnp->qsmask = rnp->qsmaskinit;
                 rnp->gpnum = rsp->gpnum;
-                spin_unlock(&rnp->lock);        /* irqs already disabled. */
+                spin_unlock(&rnp->lock);        /* irqs remain disabled. */
         }
 
+        rnp = rcu_get_root(rsp);
+        spin_lock(&rnp->lock);                  /* irqs already disabled. */
         rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state now OK. */
+        spin_unlock(&rnp->lock);                /* irqs remain disabled. */
         spin_unlock_irqrestore(&rsp->onofflock, flags);
 }
 
@@ -706,6 +709,7 @@ static void cpu_quiet_msk_finish(struct rcu_state *rsp, unsigned long flags)
 {
         WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
         rsp->completed = rsp->gpnum;
+        rsp->signaled = RCU_GP_IDLE;
         rcu_process_gp_end(rsp, rsp->rda[smp_processor_id()]);
         rcu_start_gp(rsp, flags);  /* releases root node's rnp->lock. */
 }
@@ -913,7 +917,20 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
                         spin_unlock(&rnp->lock); /* irqs remain disabled. */
                         break;
                 }
-                rcu_preempt_offline_tasks(rsp, rnp, rdp);
+
+                /*
+                 * If there was a task blocking the current grace period,
+                 * and if all CPUs have checked in, we need to propagate
+                 * the quiescent state up the rcu_node hierarchy.  But that
+                 * is inconvenient at the moment due to deadlock issues if
+                 * this should end the current grace period.  So set the
+                 * offlined CPU's bit in ->qsmask in order to force the
+                 * next force_quiescent_state() invocation to clean up this
+                 * mess in a deadlock-free manner.
+                 */
+                if (rcu_preempt_offline_tasks(rsp, rnp, rdp) && !rnp->qsmask)
+                        rnp->qsmask |= mask;
+
                 mask = rnp->grpmask;
                 spin_unlock(&rnp->lock);        /* irqs remain disabled. */
                 rnp = rnp->parent;
@@ -958,7 +975,7 @@ static void rcu_offline_cpu(int cpu)
  * Invoke any RCU callbacks that have made it to the end of their grace
  * period.  Thottle as specified by rdp->blimit.
  */
-static void rcu_do_batch(struct rcu_data *rdp)
+static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
 {
         unsigned long flags;
         struct rcu_head *next, *list, **tail;
@@ -1011,6 +1028,13 @@ static void rcu_do_batch(struct rcu_data *rdp)
         if (rdp->blimit == LONG_MAX && rdp->qlen <= qlowmark)
                 rdp->blimit = blimit;
 
+        /* Reset ->qlen_last_fqs_check trigger if enough CBs have drained. */
+        if (rdp->qlen == 0 && rdp->qlen_last_fqs_check != 0) {
+                rdp->qlen_last_fqs_check = 0;
+                rdp->n_force_qs_snap = rsp->n_force_qs;
+        } else if (rdp->qlen < rdp->qlen_last_fqs_check - qhimark)
+                rdp->qlen_last_fqs_check = rdp->qlen;
+
         local_irq_restore(flags);
 
         /* Re-raise the RCU softirq if there are callbacks remaining. */
@@ -1142,9 +1166,10 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
         }
         spin_unlock(&rnp->lock);
         switch (signaled) {
+        case RCU_GP_IDLE:
         case RCU_GP_INIT:
 
-                break; /* grace period still initializing, ignore. */
+                break; /* grace period idle or initializing, ignore. */
 
         case RCU_SAVE_DYNTICK:
 
@@ -1158,7 +1183,8 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
 
                 /* Update state, record completion counter. */
                 spin_lock(&rnp->lock);
-                if (lastcomp == rsp->completed) {
+                if (lastcomp == rsp->completed &&
+                    rsp->signaled == RCU_SAVE_DYNTICK) {
                         rsp->signaled = RCU_FORCE_QS;
                         dyntick_record_completed(rsp, lastcomp);
                 }
@@ -1224,7 +1250,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
         }
 
         /* If there are callbacks ready, invoke them. */
-        rcu_do_batch(rdp);
+        rcu_do_batch(rsp, rdp);
 }
 
 /*
@@ -1288,10 +1314,20 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
                 rcu_start_gp(rsp, nestflag);  /* releases rnp_root->lock. */
         }
 
-        /* Force the grace period if too many callbacks or too long waiting. */
-        if (unlikely(++rdp->qlen > qhimark)) {
+        /*
+         * Force the grace period if too many callbacks or too long waiting.
+         * Enforce hysteresis, and don't invoke force_quiescent_state()
+         * if some other CPU has recently done so.  Also, don't bother
+         * invoking force_quiescent_state() if the newly enqueued callback
+         * is the only one waiting for a grace period to complete.
+         */
+        if (unlikely(++rdp->qlen > rdp->qlen_last_fqs_check + qhimark)) {
                 rdp->blimit = LONG_MAX;
-                force_quiescent_state(rsp, 0);
+                if (rsp->n_force_qs == rdp->n_force_qs_snap &&
+                    *rdp->nxttail[RCU_DONE_TAIL] != head)
+                        force_quiescent_state(rsp, 0);
+                rdp->n_force_qs_snap = rsp->n_force_qs;
+                rdp->qlen_last_fqs_check = rdp->qlen;
         } else if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)
                 force_quiescent_state(rsp, 1);
         local_irq_restore(flags);
@@ -1523,6 +1559,8 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
         rdp->beenonline = 1;     /* We have now been online. */
         rdp->preemptable = preemptable;
         rdp->passed_quiesc_completed = lastcomp - 1;
+        rdp->qlen_last_fqs_check = 0;
+        rdp->n_force_qs_snap = rsp->n_force_qs;
         rdp->blimit = blimit;
         spin_unlock(&rnp->lock);                /* irqs remain disabled. */
 
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index b40ac5706040..1899023b0962 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -167,6 +167,10 @@ struct rcu_data {
         struct rcu_head *nxtlist;
         struct rcu_head **nxttail[RCU_NEXT_SIZE];
         long            qlen;           /* # of queued callbacks */
+        long            qlen_last_fqs_check;
+                                        /* qlen at last check for QS forcing */
+        unsigned long   n_force_qs_snap;
+                                        /* did other CPU force QS recently? */
         long            blimit;         /* Upper limit on a processed batch */
 
 #ifdef CONFIG_NO_HZ
@@ -197,9 +201,10 @@ struct rcu_data {
 };
 
 /* Values for signaled field in struct rcu_state. */
-#define RCU_GP_INIT             0       /* Grace period being initialized. */
-#define RCU_SAVE_DYNTICK        1       /* Need to scan dyntick state. */
-#define RCU_FORCE_QS            2       /* Need to force quiescent state. */
+#define RCU_GP_IDLE             0       /* No grace period in progress. */
+#define RCU_GP_INIT             1       /* Grace period being initialized. */
+#define RCU_SAVE_DYNTICK        2       /* Need to scan dyntick state. */
+#define RCU_FORCE_QS            3       /* Need to force quiescent state. */
 #ifdef CONFIG_NO_HZ
 #define RCU_SIGNAL_INIT         RCU_SAVE_DYNTICK
 #else /* #ifdef CONFIG_NO_HZ */
@@ -302,9 +307,9 @@ static void rcu_print_task_stall(struct rcu_node *rnp);
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
 #ifdef CONFIG_HOTPLUG_CPU
-static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-                                      struct rcu_node *rnp,
-                                      struct rcu_data *rdp);
+static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
+                                     struct rcu_node *rnp,
+                                     struct rcu_data *rdp);
 static void rcu_preempt_offline_cpu(int cpu);
 #endif /* #ifdef CONFIG_HOTPLUG_CPU */
 static void rcu_preempt_check_callbacks(int cpu);
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index c0cb783aa16a..ef2a58c2b9d5 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -304,21 +304,25 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
  * parent is to remove the need for rcu_read_unlock_special() to
  * make more than two attempts to acquire the target rcu_node's lock.
  *
+ * Returns 1 if there was previously a task blocking the current grace
+ * period on the specified rcu_node structure.
+ *
  * The caller must hold rnp->lock with irqs disabled.
  */
-static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-                                      struct rcu_node *rnp,
-                                      struct rcu_data *rdp)
+static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
+                                     struct rcu_node *rnp,
+                                     struct rcu_data *rdp)
 {
         int i;
         struct list_head *lp;
         struct list_head *lp_root;
+        int retval = rcu_preempted_readers(rnp);
         struct rcu_node *rnp_root = rcu_get_root(rsp);
         struct task_struct *tp;
 
         if (rnp == rnp_root) {
                 WARN_ONCE(1, "Last CPU thought to be offlined?");
-                return;  /* Shouldn't happen: at least one CPU online. */
+                return 0;  /* Shouldn't happen: at least one CPU online. */
         }
         WARN_ON_ONCE(rnp != rdp->mynode &&
                      (!list_empty(&rnp->blocked_tasks[0]) ||
@@ -342,6 +346,8 @@ static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
                         spin_unlock(&rnp_root->lock); /* irqs remain disabled */
                 }
         }
+
+        return retval;
 }
 
 /*
@@ -393,6 +399,17 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 EXPORT_SYMBOL_GPL(call_rcu);
 
 /*
+ * Wait for an rcu-preempt grace period.  We are supposed to expedite the
+ * grace period, but this is the crude slow compatability hack, so just
+ * invoke synchronize_rcu().
+ */
+void synchronize_rcu_expedited(void)
+{
+        synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
+
+/*
  * Check to see if there is any immediate preemptable-RCU-related work
  * to be done.
  */
@@ -521,12 +538,15 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 
 /*
  * Because preemptable RCU does not exist, it never needs to migrate
- * tasks that were blocked within RCU read-side critical sections.
+ * tasks that were blocked within RCU read-side critical sections, and
+ * such non-existent tasks cannot possibly have been blocking the current
+ * grace period.
  */
-static void rcu_preempt_offline_tasks(struct rcu_state *rsp,
-                                      struct rcu_node *rnp,
-                                      struct rcu_data *rdp)
+static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
+                                     struct rcu_node *rnp,
+                                     struct rcu_data *rdp)
 {
+        return 0;
 }
 
 /*
@@ -565,6 +585,16 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 EXPORT_SYMBOL_GPL(call_rcu);
 
 /*
+ * Wait for an rcu-preempt grace period, but make it happen quickly.
+ * But because preemptable RCU does not exist, map to rcu-sched.
+ */
+void synchronize_rcu_expedited(void)
+{
+        synchronize_sched_expedited();
+}
+EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);
+
+/*
  * Because preemptable RCU does not exist, it never has any work to do.
  */
 static int rcu_preempt_pending(int cpu)
diff --git a/kernel/sched.c b/kernel/sched.c
index 48ff66a6892d..315ba4059f93 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -309,6 +309,8 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq);
  */
 static DEFINE_SPINLOCK(task_group_lock);
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
 #ifdef CONFIG_SMP
 static int root_task_group_empty(void)
 {
@@ -316,7 +318,6 @@ static int root_task_group_empty(void)
 }
 #endif
 
-#ifdef CONFIG_FAIR_GROUP_SCHED
 #ifdef CONFIG_USER_SCHED
 # define INIT_TASK_GROUP_LOAD   (2*NICE_0_LOAD)
 #else /* !CONFIG_USER_SCHED */
@@ -1564,11 +1565,7 @@ static unsigned long cpu_avg_load_per_task(int cpu)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
-struct update_shares_data {
-        unsigned long rq_weight[NR_CPUS];
-};
-
-static DEFINE_PER_CPU(struct update_shares_data, update_shares_data);
+static __read_mostly unsigned long *update_shares_data;
 
 static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 
@@ -1578,12 +1575,12 @@ static void __set_se_shares(struct sched_entity *se, unsigned long shares);
 static void update_group_shares_cpu(struct task_group *tg, int cpu,
                                     unsigned long sd_shares,
                                     unsigned long sd_rq_weight,
-                                    struct update_shares_data *usd)
+                                    unsigned long *usd_rq_weight)
 {
         unsigned long shares, rq_weight;
         int boost = 0;
 
-        rq_weight = usd->rq_weight[cpu];
+        rq_weight = usd_rq_weight[cpu];
         if (!rq_weight) {
                 boost = 1;
                 rq_weight = NICE_0_LOAD;
@@ -1618,7 +1615,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
 static int tg_shares_up(struct task_group *tg, void *data)
 {
         unsigned long weight, rq_weight = 0, shares = 0;
-        struct update_shares_data *usd;
+        unsigned long *usd_rq_weight;
         struct sched_domain *sd = data;
         unsigned long flags;
         int i;
@@ -1627,11 +1624,11 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 return 0;
 
         local_irq_save(flags);
-        usd = &__get_cpu_var(update_shares_data);
+        usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id());
 
         for_each_cpu(i, sched_domain_span(sd)) {
                 weight = tg->cfs_rq[i]->load.weight;
-                usd->rq_weight[i] = weight;
+                usd_rq_weight[i] = weight;
 
                 /*
                  * If there are currently no tasks on the cpu pretend there
@@ -1652,7 +1649,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
                 shares = tg->shares;
 
         for_each_cpu(i, sched_domain_span(sd))
-                update_group_shares_cpu(tg, i, shares, rq_weight, usd);
+                update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight);
 
         local_irq_restore(flags);
 
@@ -1996,6 +1993,39 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p,
                 p->sched_class->prio_changed(rq, p, oldprio, running);
 }
 
+/**
+ * kthread_bind - bind a just-created kthread to a cpu.
+ * @p: thread created by kthread_create().
+ * @cpu: cpu (might not be online, must be possible) for @k to run on.
+ *
+ * Description: This function is equivalent to set_cpus_allowed(),
+ * except that @cpu doesn't need to be online, and the thread must be
+ * stopped (i.e., just returned from kthread_create()).
+ *
+ * Function lives here instead of kthread.c because it messes with
+ * scheduler internals which require locking.
+ */
+void kthread_bind(struct task_struct *p, unsigned int cpu)
+{
+        struct rq *rq = cpu_rq(cpu);
+        unsigned long flags;
+
+        /* Must have done schedule() in kthread() before we set_task_cpu */
+        if (!wait_task_inactive(p, TASK_UNINTERRUPTIBLE)) {
+                WARN_ON(1);
+                return;
+        }
+
+        spin_lock_irqsave(&rq->lock, flags);
+        update_rq_clock(rq);
+        set_task_cpu(p, cpu);
+        p->cpus_allowed = cpumask_of_cpu(cpu);
+        p->rt.nr_cpus_allowed = 1;
+        p->flags |= PF_THREAD_BOUND;
+        spin_unlock_irqrestore(&rq->lock, flags);
+}
+EXPORT_SYMBOL(kthread_bind);
+
 #ifdef CONFIG_SMP
 /*
  * Is this task likely cache-hot:
@@ -2008,7 +2038,7 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
         /*
          * Buddy candidates are cache hot:
          */
-        if (sched_feat(CACHE_HOT_BUDDY) &&
+        if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
                         (&p->se == cfs_rq_of(&p->se)->next ||
                          &p->se == cfs_rq_of(&p->se)->last))
                 return 1;
@@ -2085,6 +2115,7 @@ migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req)
          * it is sufficient to simply update the task's cpu field.
          */
         if (!p->se.on_rq && !task_running(rq, p)) {
+                update_rq_clock(rq);
                 set_task_cpu(p, dest_cpu);
                 return 0;
         }
@@ -2346,14 +2377,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
         task_rq_unlock(rq, &flags);
 
         cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
-        if (cpu != orig_cpu)
+        if (cpu != orig_cpu) {
+                local_irq_save(flags);
+                rq = cpu_rq(cpu);
+                update_rq_clock(rq);
                 set_task_cpu(p, cpu);
-
+                local_irq_restore(flags);
+        }
         rq = task_rq_lock(p, &flags);
 
-        if (rq != orig_rq)
-                update_rq_clock(rq);
-
         WARN_ON(p->state != TASK_WAKING);
         cpu = task_cpu(p);
 
@@ -2526,6 +2558,7 @@ static void __sched_fork(struct task_struct *p)
 void sched_fork(struct task_struct *p, int clone_flags)
 {
         int cpu = get_cpu();
+        unsigned long flags;
 
         __sched_fork(p);
 
@@ -2562,7 +2595,10 @@ void sched_fork(struct task_struct *p, int clone_flags)
 #ifdef CONFIG_SMP
         cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0);
 #endif
+        local_irq_save(flags);
+        update_rq_clock(cpu_rq(cpu));
         set_task_cpu(p, cpu);
+        local_irq_restore(flags);
 
 #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
         if (likely(sched_info_on()))
@@ -2732,9 +2768,9 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
         prev_state = prev->state;
         finish_arch_switch(prev);
         perf_event_task_sched_in(current, cpu_of(rq));
+        fire_sched_in_preempt_notifiers(current);
         finish_lock_switch(rq, prev);
 
-        fire_sched_in_preempt_notifiers(current);
         if (mm)
                 mmdrop(mm);
         if (unlikely(prev_state == TASK_DEAD)) {
@@ -7898,6 +7934,8 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
 
 static void free_rootdomain(struct root_domain *rd)
 {
+        synchronize_sched();
+
         cpupri_cleanup(&rd->cpupri);
 
         free_cpumask_var(rd->rto_mask);
@@ -9449,6 +9487,10 @@ void __init sched_init(void)
 #endif /* CONFIG_USER_SCHED */
 #endif /* CONFIG_GROUP_SCHED */
 
+#if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP
+        update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long),
+                                            __alignof__(unsigned long));
+#endif
         for_each_possible_cpu(i) {
                 struct rq *rq;
 
@@ -9576,13 +9618,13 @@ void __init sched_init(void)
         current->sched_class = &fair_sched_class;
 
         /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */
-        alloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT);
 #ifdef CONFIG_SMP
 #ifdef CONFIG_NO_HZ
-        alloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
+        zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT);
         alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT);
 #endif
-        alloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
+        zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
 #endif /* SMP */
 
         perf_event_init();
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 24086e7e7593..f61837ad336d 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -822,6 +822,26 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
                  * re-elected due to buddy favours.
                  */
                 clear_buddies(cfs_rq, curr);
+                return;
+        }
+
+        /*
+         * Ensure that a task that missed wakeup preemption by a
+         * narrow margin doesn't have to wait for a full slice.
+         * This also mitigates buddy induced latencies under load.
+         */
+        if (!sched_feat(WAKEUP_PREEMPT))
+                return;
+
+        if (delta_exec < sysctl_sched_min_granularity)
+                return;
+
+        if (cfs_rq->nr_running > 1) {
+                struct sched_entity *se = __pick_next_entity(cfs_rq);
+                s64 delta = curr->vruntime - se->vruntime;
+
+                if (delta > ideal_runtime)
+                        resched_task(rq_of(cfs_rq)->curr);
         }
 }
 
@@ -861,12 +881,18 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
 static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
 {
         struct sched_entity *se = __pick_next_entity(cfs_rq);
+        struct sched_entity *left = se;
 
-        if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, se) < 1)
-                return cfs_rq->next;
+        if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
+                se = cfs_rq->next;
 
-        if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, se) < 1)
-                return cfs_rq->last;
+        /*
+         * Prefer last buddy, try to return the CPU to a preempted task.
+         */
+        if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
+                se = cfs_rq->last;
+
+        clear_buddies(cfs_rq, se);
 
         return se;
 }
@@ -1623,6 +1649,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
         struct sched_entity *se = &curr->se, *pse = &p->se;
         struct cfs_rq *cfs_rq = task_cfs_rq(curr);
         int sync = wake_flags & WF_SYNC;
+        int scale = cfs_rq->nr_running >= sched_nr_latency;
 
         update_curr(cfs_rq);
 
@@ -1637,18 +1664,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
         if (unlikely(se == pse))
                 return;
 
-        /*
-         * Only set the backward buddy when the current task is still on the
-         * rq. This can happen when a wakeup gets interleaved with schedule on
-         * the ->pre_schedule() or idle_balance() point, either of which can
-         * drop the rq lock.
-         *
-         * Also, during early boot the idle thread is in the fair class, for
-         * obvious reasons its a bad idea to schedule back to the idle thread.
-         */
-        if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle))
-                set_last_buddy(se);
-        if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK))
+        if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK))
                 set_next_buddy(pse);
 
         /*
@@ -1694,8 +1710,22 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 
         BUG_ON(!pse);
 
-        if (wakeup_preempt_entity(se, pse) == 1)
+        if (wakeup_preempt_entity(se, pse) == 1) {
                 resched_task(curr);
+                /*
+                 * Only set the backward buddy when the current task is still
+                 * on the rq. This can happen when a wakeup gets interleaved
+                 * with schedule on the ->pre_schedule() or idle_balance()
+                 * point, either of which can * drop the rq lock.
+                 *
+                 * Also, during early boot the idle thread is in the fair class,
+                 * for obvious reasons its a bad idea to schedule back to it.
+                 */
+                if (unlikely(!se->on_rq || curr == rq->idle))
+                        return;
+                if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
+                        set_last_buddy(se);
+        }
 }
 
 static struct task_struct *pick_next_task_fair(struct rq *rq)
@@ -1709,16 +1739,6 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
 
         do {
                 se = pick_next_entity(cfs_rq);
-                /*
-                 * If se was a buddy, clear it so that it will have to earn
-                 * the favour again.
-                 *
-                 * If se was not a buddy, clear the buddies because neither
-                 * was elegible to run, let them earn it again.
-                 *
-                 * IOW. unconditionally clear buddies.
-                 */
-                __clear_buddies(cfs_rq, NULL);
                 set_next_entity(cfs_rq, se);
                 cfs_rq = group_cfs_rq(se);
         } while (cfs_rq);
diff --git a/kernel/sys.c b/kernel/sys.c
index 255475d163e0..ce17760d9c51 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1110,6 +1110,8 @@ SYSCALL_DEFINE0(setsid)
         err = session;
 out:
         write_unlock_irq(&tasklist_lock);
+        if (err > 0)
+                proc_sid_connector(group_leader);
         return err;
 }
 
@@ -1546,24 +1548,37 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
                         if (arg4 | arg5)
                                 return -EINVAL;
                         switch (arg2) {
-                        case 0:
+                        case PR_MCE_KILL_CLEAR:
                                 if (arg3 != 0)
                                         return -EINVAL;
                                 current->flags &= ~PF_MCE_PROCESS;
                                 break;
-                        case 1:
+                        case PR_MCE_KILL_SET:
                                 current->flags |= PF_MCE_PROCESS;
-                                if (arg3 != 0)
+                                if (arg3 == PR_MCE_KILL_EARLY)
                                         current->flags |= PF_MCE_EARLY;
-                                else
+                                else if (arg3 == PR_MCE_KILL_LATE)
                                         current->flags &= ~PF_MCE_EARLY;
+                                else if (arg3 == PR_MCE_KILL_DEFAULT)
+                                        current->flags &=
+                                                ~(PF_MCE_EARLY|PF_MCE_PROCESS);
+                                else
+                                        return -EINVAL;
                                 break;
                         default:
                                 return -EINVAL;
                         }
                         error = 0;
                         break;
-
+                case PR_MCE_KILL_GET:
+                        if (arg2 | arg3 | arg4 | arg5)
+                                return -EINVAL;
+                        if (current->flags & PF_MCE_PROCESS)
+                                error = (current->flags & PF_MCE_EARLY) ?
+                                        PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
+                        else
+                                error = PR_MCE_KILL_DEFAULT;
+                        break;
                 default:
                         error = -EINVAL;
                         break;
diff --git a/kernel/sysctl_check.c b/kernel/sysctl_check.c
index b38423ca711a..b6e7aaea4604 100644
--- a/kernel/sysctl_check.c
+++ b/kernel/sysctl_check.c
@@ -1521,7 +1521,7 @@ int sysctl_check_table(struct nsproxy *namespaces, struct ctl_table *table)
                         if (!table->ctl_name && table->strategy)
                                 set_fail(&fail, table, "Strategy without ctl_name");
 #endif
-#ifdef CONFIG_PROC_FS
+#ifdef CONFIG_PROC_SYSCTL
                         if (table->procname && !table->proc_handler)
                                 set_fail(&fail, table, "No proc_handler");
 #endif
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 37ba67e33265..6dc4e5ef7a01 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -740,7 +740,7 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
  out:
         mutex_unlock(&ftrace_profile_lock);
 
-        filp->f_pos += cnt;
+        *ppos += cnt;
 
         return cnt;
 }
@@ -2222,15 +2222,15 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
                 ret = ftrace_process_regex(parser->buffer,
                                            parser->idx, enable);
                 if (ret)
-                        goto out;
+                        goto out_unlock;
 
                 trace_parser_clear(parser);
         }
 
         ret = read;
-
+out_unlock:
         mutex_unlock(&ftrace_regex_lock);
-out:
+
         return ret;
 }
 
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d4ff01970547..5dd017fea6f5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -483,7 +483,7 @@ struct ring_buffer_iter {
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
-static inline u64 rb_time_stamp(struct ring_buffer *buffer, int cpu)
+static inline u64 rb_time_stamp(struct ring_buffer *buffer)
 {
         /* shift to debug/test normalization and TIME_EXTENTS */
         return buffer->clock() << DEBUG_SHIFT;
@@ -494,7 +494,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
         u64 time;
 
         preempt_disable_notrace();
-        time = rb_time_stamp(buffer, cpu);
+        time = rb_time_stamp(buffer);
         preempt_enable_no_resched_notrace();
 
         return time;
@@ -599,7 +599,7 @@ static struct list_head *rb_list_head(struct list_head *list)
 }
 
 /*
- * rb_is_head_page - test if the give page is the head page
+ * rb_is_head_page - test if the given page is the head page
  *
  * Because the reader may move the head_page pointer, we can
  * not trust what the head page is (it may be pointing to
@@ -1193,6 +1193,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
         atomic_inc(&cpu_buffer->record_disabled);
         synchronize_sched();
 
+        spin_lock_irq(&cpu_buffer->reader_lock);
         rb_head_page_deactivate(cpu_buffer);
 
         for (i = 0; i < nr_pages; i++) {
@@ -1207,6 +1208,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
                 return;
 
         rb_reset_cpu(cpu_buffer);
+        spin_unlock_irq(&cpu_buffer->reader_lock);
 
         rb_check_pages(cpu_buffer);
 
@@ -1868,7 +1870,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
                  * Nested commits always have zero deltas, so
                  * just reread the time stamp
                  */
-                *ts = rb_time_stamp(buffer, cpu_buffer->cpu);
+                *ts = rb_time_stamp(buffer);
                 next_page->page->time_stamp = *ts;
         }
 
@@ -2111,7 +2113,7 @@ rb_reserve_next_event(struct ring_buffer *buffer,
         if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
                 goto out_fail;
 
-        ts = rb_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu);
+        ts = rb_time_stamp(cpu_buffer->buffer);
 
         /*
          * Only the first commit can update the timestamp.
@@ -2681,7 +2683,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer)
 EXPORT_SYMBOL_GPL(ring_buffer_entries);
 
 /**
- * ring_buffer_overrun_cpu - get the number of overruns in buffer
+ * ring_buffer_overruns - get the number of overruns in buffer
  * @buffer: The ring buffer
  *
  * Returns the total number of overruns in the ring buffer
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c820b0310a12..b20d3ec75de9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2440,7 +2440,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf,
                         return ret;
         }
 
-        filp->f_pos += cnt;
+        *ppos += cnt;
 
         return cnt;
 }
@@ -2582,7 +2582,7 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
         }
         mutex_unlock(&trace_types_lock);
 
-        filp->f_pos += cnt;
+        *ppos += cnt;
 
         return cnt;
 }
@@ -2764,7 +2764,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
         if (err)
                 return err;
 
-        filp->f_pos += ret;
+        *ppos += ret;
 
         return ret;
 }
@@ -3299,7 +3299,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
                 }
         }
 
-        filp->f_pos += cnt;
+        *ppos += cnt;
 
         /* If check pages failed, return ENOMEM */
         if (tracing_disabled)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index ed17565826b0..b6c12c6a1bcd 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -69,6 +69,9 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
  * @s: trace sequence descriptor
  * @fmt: printf format string
  *
+ * It returns 0 if the trace oversizes the buffer's free
+ * space, 1 otherwise.
+ *
  * The tracer may use either sequence operations or its own
  * copy to user routines. To simplify formating of a trace
  * trace_seq_printf is used to store strings into a special
@@ -95,7 +98,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
 
         s->len += ret;
 
-        return len;
+        return 1;
 }
 EXPORT_SYMBOL_GPL(trace_seq_printf);
 
diff --git a/kernel/user.c b/kernel/user.c
index 2c000e7132ac..46d0165ca70c 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -330,9 +330,9 @@ done:
  */
 static void free_user(struct user_struct *up, unsigned long flags)
 {
-        spin_unlock_irqrestore(&uidhash_lock, flags);
         INIT_DELAYED_WORK(&up->work, cleanup_user_struct);
         schedule_delayed_work(&up->work, msecs_to_jiffies(1000));
+        spin_unlock_irqrestore(&uidhash_lock, flags);
 }
 
 #else   /* CONFIG_USER_SCHED && CONFIG_SYSFS */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 47cdd7e76f2b..12328147132c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -685,21 +685,38 @@ EXPORT_SYMBOL(schedule_delayed_work_on);
 int schedule_on_each_cpu(work_func_t func)
 {
         int cpu;
+        int orig = -1;
         struct work_struct *works;
 
         works = alloc_percpu(struct work_struct);
         if (!works)
                 return -ENOMEM;
 
+        /*
+         * when running in keventd don't schedule a work item on itself.
+         * Can just call directly because the work queue is already bound.
+         * This also is faster.
+         * Make this a generic parameter for other workqueues?
+         */
+        if (current_is_keventd()) {
+                orig = raw_smp_processor_id();
+                INIT_WORK(per_cpu_ptr(works, orig), func);
+                func(per_cpu_ptr(works, orig));
+        }
+
         get_online_cpus();
         for_each_online_cpu(cpu) {
                 struct work_struct *work = per_cpu_ptr(works, cpu);
 
+                if (cpu == orig)
+                        continue;
                 INIT_WORK(work, func);
                 schedule_work_on(cpu, work);
         }
-        for_each_online_cpu(cpu)
-                flush_work(per_cpu_ptr(works, cpu));
+        for_each_online_cpu(cpu) {
+                if (cpu != orig)
+                        flush_work(per_cpu_ptr(works, cpu));
+        }
         put_online_cpus();
         free_percpu(works);
         return 0;