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-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/cgroup.c15
-rw-r--r--kernel/exit.c14
-rw-r--r--kernel/fork.c1
-rw-r--r--kernel/kprobes.c1
-rw-r--r--kernel/lockdep.c18
-rw-r--r--kernel/notifier.c6
-rw-r--r--kernel/padata.c690
-rw-r--r--kernel/pid.c2
-rw-r--r--kernel/power/Kconfig19
-rw-r--r--kernel/power/main.c31
-rw-r--r--kernel/power/snapshot.c4
-rw-r--r--kernel/power/swap.c4
-rw-r--r--kernel/power/swsusp.c58
-rw-r--r--kernel/power/user.c23
-rw-r--r--kernel/rcupdate.c29
-rw-r--r--kernel/rcutorture.c94
-rw-r--r--kernel/rcutree.c268
-rw-r--r--kernel/rcutree.h61
-rw-r--r--kernel/rcutree_plugin.h229
-rw-r--r--kernel/rcutree_trace.c14
-rw-r--r--kernel/resource.c44
-rw-r--r--kernel/sched.c11
-rw-r--r--kernel/smp.c8
-rw-r--r--kernel/srcu.c52
25 files changed, 1394 insertions, 303 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 864ff75d65f2..6aebdeb2aa34 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-work-debugfs.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
+obj-$(CONFIG_PADATA) += padata.o
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index aa3bee566446..4fd90e129772 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -23,6 +23,7 @@
*/
#include <linux/cgroup.h>
+#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/fs.h>
@@ -166,6 +167,20 @@ static DEFINE_SPINLOCK(hierarchy_id_lock);
*/
static int need_forkexit_callback __read_mostly;
+#ifdef CONFIG_PROVE_LOCKING
+int cgroup_lock_is_held(void)
+{
+ return lockdep_is_held(&cgroup_mutex);
+}
+#else /* #ifdef CONFIG_PROVE_LOCKING */
+int cgroup_lock_is_held(void)
+{
+ return mutex_is_locked(&cgroup_mutex);
+}
+#endif /* #else #ifdef CONFIG_PROVE_LOCKING */
+
+EXPORT_SYMBOL_GPL(cgroup_lock_is_held);
+
/* convenient tests for these bits */
inline int cgroup_is_removed(const struct cgroup *cgrp)
{
diff --git a/kernel/exit.c b/kernel/exit.c
index 546774a31a66..45ed043b8bf5 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -85,7 +85,9 @@ static void __exit_signal(struct task_struct *tsk)
BUG_ON(!sig);
BUG_ON(!atomic_read(&sig->count));
- sighand = rcu_dereference(tsk->sighand);
+ sighand = rcu_dereference_check(tsk->sighand,
+ rcu_read_lock_held() ||
+ lockdep_is_held(&tasklist_lock));
spin_lock(&sighand->siglock);
posix_cpu_timers_exit(tsk);
@@ -170,8 +172,10 @@ void release_task(struct task_struct * p)
repeat:
tracehook_prepare_release_task(p);
/* don't need to get the RCU readlock here - the process is dead and
- * can't be modifying its own credentials */
+ * can't be modifying its own credentials. But shut RCU-lockdep up */
+ rcu_read_lock();
atomic_dec(&__task_cred(p)->user->processes);
+ rcu_read_unlock();
proc_flush_task(p);
@@ -473,9 +477,11 @@ static void close_files(struct files_struct * files)
/*
* It is safe to dereference the fd table without RCU or
* ->file_lock because this is the last reference to the
- * files structure.
+ * files structure. But use RCU to shut RCU-lockdep up.
*/
+ rcu_read_lock();
fdt = files_fdtable(files);
+ rcu_read_unlock();
for (;;) {
unsigned long set;
i = j * __NFDBITS;
@@ -521,10 +527,12 @@ void put_files_struct(struct files_struct *files)
* at the end of the RCU grace period. Otherwise,
* you can free files immediately.
*/
+ rcu_read_lock();
fdt = files_fdtable(files);
if (fdt != &files->fdtab)
kmem_cache_free(files_cachep, files);
free_fdtable(fdt);
+ rcu_read_unlock();
}
}
diff --git a/kernel/fork.c b/kernel/fork.c
index f88bd984df35..17bbf093356d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -86,6 +86,7 @@ int max_threads; /* tunable limit on nr_threads */
DEFINE_PER_CPU(unsigned long, process_counts) = 0;
__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+EXPORT_SYMBOL_GPL(tasklist_lock);
int nr_processes(void)
{
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b7df302a0204..c4b43430d393 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -93,6 +93,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
{"native_get_debugreg",},
{"irq_entries_start",},
{"common_interrupt",},
+ {"mcount",}, /* mcount can be called from everywhere */
{NULL} /* Terminator */
};
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c62ec14609b9..0c30d0455de1 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3809,3 +3809,21 @@ void lockdep_sys_exit(void)
lockdep_print_held_locks(curr);
}
}
+
+void lockdep_rcu_dereference(const char *file, const int line)
+{
+ struct task_struct *curr = current;
+
+ if (!debug_locks_off())
+ return;
+ printk("\n===================================================\n");
+ printk( "[ INFO: suspicious rcu_dereference_check() usage. ]\n");
+ printk( "---------------------------------------------------\n");
+ printk("%s:%d invoked rcu_dereference_check() without protection!\n",
+ file, line);
+ printk("\nother info that might help us debug this:\n\n");
+ lockdep_print_held_locks(curr);
+ printk("\nstack backtrace:\n");
+ dump_stack();
+}
+EXPORT_SYMBOL_GPL(lockdep_rcu_dereference);
diff --git a/kernel/notifier.c b/kernel/notifier.c
index acd24e7643eb..2488ba7eb568 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -78,10 +78,10 @@ static int __kprobes notifier_call_chain(struct notifier_block **nl,
int ret = NOTIFY_DONE;
struct notifier_block *nb, *next_nb;
- nb = rcu_dereference(*nl);
+ nb = rcu_dereference_raw(*nl);
while (nb && nr_to_call) {
- next_nb = rcu_dereference(nb->next);
+ next_nb = rcu_dereference_raw(nb->next);
#ifdef CONFIG_DEBUG_NOTIFIERS
if (unlikely(!func_ptr_is_kernel_text(nb->notifier_call))) {
@@ -309,7 +309,7 @@ int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
* racy then it does not matter what the result of the test
* is, we re-check the list after having taken the lock anyway:
*/
- if (rcu_dereference(nh->head)) {
+ if (rcu_dereference_raw(nh->head)) {
down_read(&nh->rwsem);
ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
nr_calls);
diff --git a/kernel/padata.c b/kernel/padata.c
new file mode 100644
index 000000000000..6f9bcb8313d6
--- /dev/null
+++ b/kernel/padata.c
@@ -0,0 +1,690 @@
+/*
+ * padata.c - generic interface to process data streams in parallel
+ *
+ * Copyright (C) 2008, 2009 secunet Security Networks AG
+ * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/module.h>
+#include <linux/cpumask.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/padata.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/rcupdate.h>
+
+#define MAX_SEQ_NR INT_MAX - NR_CPUS
+#define MAX_OBJ_NUM 10000 * NR_CPUS
+
+static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
+{
+ int cpu, target_cpu;
+
+ target_cpu = cpumask_first(pd->cpumask);
+ for (cpu = 0; cpu < cpu_index; cpu++)
+ target_cpu = cpumask_next(target_cpu, pd->cpumask);
+
+ return target_cpu;
+}
+
+static int padata_cpu_hash(struct padata_priv *padata)
+{
+ int cpu_index;
+ struct parallel_data *pd;
+
+ pd = padata->pd;
+
+ /*
+ * Hash the sequence numbers to the cpus by taking
+ * seq_nr mod. number of cpus in use.
+ */
+ cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask);
+
+ return padata_index_to_cpu(pd, cpu_index);
+}
+
+static void padata_parallel_worker(struct work_struct *work)
+{
+ struct padata_queue *queue;
+ struct parallel_data *pd;
+ struct padata_instance *pinst;
+ LIST_HEAD(local_list);
+
+ local_bh_disable();
+ queue = container_of(work, struct padata_queue, pwork);
+ pd = queue->pd;
+ pinst = pd->pinst;
+
+ spin_lock(&queue->parallel.lock);
+ list_replace_init(&queue->parallel.list, &local_list);
+ spin_unlock(&queue->parallel.lock);
+
+ while (!list_empty(&local_list)) {
+ struct padata_priv *padata;
+
+ padata = list_entry(local_list.next,
+ struct padata_priv, list);
+
+ list_del_init(&padata->list);
+
+ padata->parallel(padata);
+ }
+
+ local_bh_enable();
+}
+
+/*
+ * padata_do_parallel - padata parallelization function
+ *
+ * @pinst: padata instance
+ * @padata: object to be parallelized
+ * @cb_cpu: cpu the serialization callback function will run on,
+ * must be in the cpumask of padata.
+ *
+ * The parallelization callback function will run with BHs off.
+ * Note: Every object which is parallelized by padata_do_parallel
+ * must be seen by padata_do_serial.
+ */
+int padata_do_parallel(struct padata_instance *pinst,
+ struct padata_priv *padata, int cb_cpu)
+{
+ int target_cpu, err;
+ struct padata_queue *queue;
+ struct parallel_data *pd;
+
+ rcu_read_lock_bh();
+
+ pd = rcu_dereference(pinst->pd);
+
+ err = 0;
+ if (!(pinst->flags & PADATA_INIT))
+ goto out;
+
+ err = -EBUSY;
+ if ((pinst->flags & PADATA_RESET))
+ goto out;
+
+ if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
+ goto out;
+
+ err = -EINVAL;
+ if (!cpumask_test_cpu(cb_cpu, pd->cpumask))
+ goto out;
+
+ err = -EINPROGRESS;
+ atomic_inc(&pd->refcnt);
+ padata->pd = pd;
+ padata->cb_cpu = cb_cpu;
+
+ if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr))
+ atomic_set(&pd->seq_nr, -1);
+
+ padata->seq_nr = atomic_inc_return(&pd->seq_nr);
+
+ target_cpu = padata_cpu_hash(padata);
+ queue = per_cpu_ptr(pd->queue, target_cpu);
+
+ spin_lock(&queue->parallel.lock);
+ list_add_tail(&padata->list, &queue->parallel.list);
+ spin_unlock(&queue->parallel.lock);
+
+ queue_work_on(target_cpu, pinst->wq, &queue->pwork);
+
+out:
+ rcu_read_unlock_bh();
+
+ return err;
+}
+EXPORT_SYMBOL(padata_do_parallel);
+
+static struct padata_priv *padata_get_next(struct parallel_data *pd)
+{
+ int cpu, num_cpus, empty, calc_seq_nr;
+ int seq_nr, next_nr, overrun, next_overrun;
+ struct padata_queue *queue, *next_queue;
+ struct padata_priv *padata;
+ struct padata_list *reorder;
+
+ empty = 0;
+ next_nr = -1;
+ next_overrun = 0;
+ next_queue = NULL;
+
+ num_cpus = cpumask_weight(pd->cpumask);
+
+ for_each_cpu(cpu, pd->cpumask) {
+ queue = per_cpu_ptr(pd->queue, cpu);
+ reorder = &queue->reorder;
+
+ /*
+ * Calculate the seq_nr of the object that should be
+ * next in this queue.
+ */
+ overrun = 0;
+ calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus)
+ + queue->cpu_index;
+
+ if (unlikely(calc_seq_nr > pd->max_seq_nr)) {
+ calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1;
+ overrun = 1;
+ }
+
+ if (!list_empty(&reorder->list)) {
+ padata = list_entry(reorder->list.next,
+ struct padata_priv, list);
+
+ seq_nr = padata->seq_nr;
+ BUG_ON(calc_seq_nr != seq_nr);
+ } else {
+ seq_nr = calc_seq_nr;
+ empty++;
+ }
+
+ if (next_nr < 0 || seq_nr < next_nr
+ || (next_overrun && !overrun)) {
+ next_nr = seq_nr;
+ next_overrun = overrun;
+ next_queue = queue;
+ }
+ }
+
+ padata = NULL;
+
+ if (empty == num_cpus)
+ goto out;
+
+ reorder = &next_queue->reorder;
+
+ if (!list_empty(&reorder->list)) {
+ padata = list_entry(reorder->list.next,
+ struct padata_priv, list);
+
+ if (unlikely(next_overrun)) {
+ for_each_cpu(cpu, pd->cpumask) {
+ queue = per_cpu_ptr(pd->queue, cpu);
+ atomic_set(&queue->num_obj, 0);
+ }
+ }
+
+ spin_lock(&reorder->lock);
+ list_del_init(&padata->list);
+ atomic_dec(&pd->reorder_objects);
+ spin_unlock(&reorder->lock);
+
+ atomic_inc(&next_queue->num_obj);
+
+ goto out;
+ }
+
+ if (next_nr % num_cpus == next_queue->cpu_index) {
+ padata = ERR_PTR(-ENODATA);
+ goto out;
+ }
+
+ padata = ERR_PTR(-EINPROGRESS);
+out:
+ return padata;
+}
+
+static void padata_reorder(struct parallel_data *pd)
+{
+ struct padata_priv *padata;
+ struct padata_queue *queue;
+ struct padata_instance *pinst = pd->pinst;
+
+try_again:
+ if (!spin_trylock_bh(&pd->lock))
+ goto out;
+
+ while (1) {
+ padata = padata_get_next(pd);
+
+ if (!padata || PTR_ERR(padata) == -EINPROGRESS)
+ break;
+
+ if (PTR_ERR(padata) == -ENODATA) {
+ spin_unlock_bh(&pd->lock);
+ goto out;
+ }
+
+ queue = per_cpu_ptr(pd->queue, padata->cb_cpu);
+
+ spin_lock(&queue->serial.lock);
+ list_add_tail(&padata->list, &queue->serial.list);
+ spin_unlock(&queue->serial.lock);
+
+ queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork);
+ }
+
+ spin_unlock_bh(&pd->lock);
+
+ if (atomic_read(&pd->reorder_objects))
+ goto try_again;
+
+out:
+ return;
+}
+
+static void padata_serial_worker(struct work_struct *work)
+{
+ struct padata_queue *queue;
+ struct parallel_data *pd;
+ LIST_HEAD(local_list);
+
+ local_bh_disable();
+ queue = container_of(work, struct padata_queue, swork);
+ pd = queue->pd;
+
+ spin_lock(&queue->serial.lock);
+ list_replace_init(&queue->serial.list, &local_list);
+ spin_unlock(&queue->serial.lock);
+
+ while (!list_empty(&local_list)) {
+ struct padata_priv *padata;
+
+ padata = list_entry(local_list.next,
+ struct padata_priv, list);
+
+ list_del_init(&padata->list);
+
+ padata->serial(padata);
+ atomic_dec(&pd->refcnt);
+ }
+ local_bh_enable();
+}
+
+/*
+ * padata_do_serial - padata serialization function
+ *
+ * @padata: object to be serialized.
+ *
+ * padata_do_serial must be called for every parallelized object.
+ * The serialization callback function will run with BHs off.
+ */
+void padata_do_serial(struct padata_priv *padata)
+{
+ int cpu;
+ struct padata_queue *queue;
+ struct parallel_data *pd;
+
+ pd = padata->pd;
+
+ cpu = get_cpu();
+ queue = per_cpu_ptr(pd->queue, cpu);
+
+ spin_lock(&queue->reorder.lock);
+ atomic_inc(&pd->reorder_objects);
+ list_add_tail(&padata->list, &queue->reorder.list);
+ spin_unlock(&queue->reorder.lock);
+
+ put_cpu();
+
+ padata_reorder(pd);
+}
+EXPORT_SYMBOL(padata_do_serial);
+
+static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
+ const struct cpumask *cpumask)
+{
+ int cpu, cpu_index, num_cpus;
+ struct padata_queue *queue;
+ struct parallel_data *pd;
+
+ cpu_index = 0;
+
+ pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
+ if (!pd)
+ goto err;
+
+ pd->queue = alloc_percpu(struct padata_queue);
+ if (!pd->queue)
+ goto err_free_pd;
+
+ if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL))
+ goto err_free_queue;
+
+ for_each_possible_cpu(cpu) {
+ queue = per_cpu_ptr(pd->queue, cpu);
+
+ queue->pd = pd;
+
+ if (cpumask_test_cpu(cpu, cpumask)
+ && cpumask_test_cpu(cpu, cpu_active_mask)) {
+ queue->cpu_index = cpu_index;
+ cpu_index++;
+ } else
+ queue->cpu_index = -1;
+
+ INIT_LIST_HEAD(&queue->reorder.list);
+ INIT_LIST_HEAD(&queue->parallel.list);
+ INIT_LIST_HEAD(&queue->serial.list);
+ spin_lock_init(&queue->reorder.lock);
+ spin_lock_init(&queue->parallel.lock);
+ spin_lock_init(&queue->serial.lock);
+
+ INIT_WORK(&queue->pwork, padata_parallel_worker);
+ INIT_WORK(&queue->swork, padata_serial_worker);
+ atomic_set(&queue->num_obj, 0);
+ }
+
+ cpumask_and(pd->cpumask, cpumask, cpu_active_mask);
+
+ num_cpus = cpumask_weight(pd->cpumask);
+ pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
+
+ atomic_set(&pd->seq_nr, -1);
+ atomic_set(&pd->reorder_objects, 0);
+ atomic_set(&pd->refcnt, 0);
+ pd->pinst = pinst;
+ spin_lock_init(&pd->lock);
+
+ return pd;
+
+err_free_queue:
+ free_percpu(pd->queue);
+err_free_pd:
+ kfree(pd);
+err:
+ return NULL;
+}
+
+static void padata_free_pd(struct parallel_data *pd)
+{
+ free_cpumask_var(pd->cpumask);
+ free_percpu(pd->queue);
+ kfree(pd);
+}
+
+static void padata_replace(struct padata_instance *pinst,
+ struct parallel_data *pd_new)
+{
+ struct parallel_data *pd_old = pinst->pd;
+
+ pinst->flags |= PADATA_RESET;
+
+ rcu_assign_pointer(pinst->pd, pd_new);
+
+ synchronize_rcu();
+
+ while (atomic_read(&pd_old->refcnt) != 0)
+ yield();
+
+ flush_workqueue(pinst->wq);
+
+ padata_free_pd(pd_old);
+
+ pinst->flags &= ~PADATA_RESET;
+}
+
+/*
+ * padata_set_cpumask - set the cpumask that padata should use
+ *
+ * @pinst: padata instance
+ * @cpumask: the cpumask to use
+ */
+int padata_set_cpumask(struct padata_instance *pinst,
+ cpumask_var_t cpumask)
+{
+ struct parallel_data *pd;
+ int err = 0;
+
+ might_sleep();
+
+ mutex_lock(&pinst->lock);
+
+ pd = padata_alloc_pd(pinst, cpumask);
+ if (!pd) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ cpumask_copy(pinst->cpumask, cpumask);
+
+ padata_replace(pinst, pd);
+
+out:
+ mutex_unlock(&pinst->lock);
+
+ return err;
+}
+EXPORT_SYMBOL(padata_set_cpumask);
+
+static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
+{
+ struct parallel_data *pd;
+
+ if (cpumask_test_cpu(cpu, cpu_active_mask)) {
+ pd = padata_alloc_pd(pinst, pinst->cpumask);
+ if (!pd)
+ return -ENOMEM;
+
+ padata_replace(pinst, pd);
+ }
+
+ return 0;
+}
+
+/*
+ * padata_add_cpu - add a cpu to the padata cpumask
+ *
+ * @pinst: padata instance
+ * @cpu: cpu to add
+ */
+int padata_add_cpu(struct padata_instance *pinst, int cpu)
+{
+ int err;
+
+ might_sleep();
+
+ mutex_lock(&pinst->lock);
+
+ cpumask_set_cpu(cpu, pinst->cpumask);
+ err = __padata_add_cpu(pinst, cpu);
+
+ mutex_unlock(&pinst->lock);
+
+ return err;
+}
+EXPORT_SYMBOL(padata_add_cpu);
+
+static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
+{
+ struct parallel_data *pd;
+
+ if (cpumask_test_cpu(cpu, cpu_online_mask)) {
+ pd = padata_alloc_pd(pinst, pinst->cpumask);
+ if (!pd)
+ return -ENOMEM;
+
+ padata_replace(pinst, pd);
+ }
+
+ return 0;
+}
+
+/*
+ * padata_remove_cpu - remove a cpu from the padata cpumask
+ *
+ * @pinst: padata instance
+ * @cpu: cpu to remove
+ */
+int padata_remove_cpu(struct padata_instance *pinst, int cpu)
+{
+ int err;
+
+ might_sleep();
+
+ mutex_lock(&pinst->lock);
+
+ cpumask_clear_cpu(cpu, pinst->cpumask);
+ err = __padata_remove_cpu(pinst, cpu);
+
+ mutex_unlock(&pinst->lock);
+
+ return err;
+}
+EXPORT_SYMBOL(padata_remove_cpu);
+
+/*
+ * padata_start - start the parallel processing
+ *
+ * @pinst: padata instance to start
+ */
+void padata_start(struct padata_instance *pinst)
+{
+ might_sleep();
+
+ mutex_lock(&pinst->lock);
+ pinst->flags |= PADATA_INIT;
+ mutex_unlock(&pinst->lock);
+}
+EXPORT_SYMBOL(padata_start);
+
+/*
+ * padata_stop - stop the parallel processing
+ *
+ * @pinst: padata instance to stop
+ */
+void padata_stop(struct padata_instance *pinst)
+{
+ might_sleep();
+
+ mutex_lock(&pinst->lock);
+ pinst->flags &= ~PADATA_INIT;
+ mutex_unlock(&pinst->lock);
+}
+EXPORT_SYMBOL(padata_stop);
+
+static int __cpuinit padata_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ int err;
+ struct padata_instance *pinst;
+ int cpu = (unsigned long)hcpu;
+
+ pinst = container_of(nfb, struct padata_instance, cpu_notifier);
+
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ break;
+ mutex_lock(&pinst->lock);
+ err = __padata_add_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+ if (err)
+ return NOTIFY_BAD;
+ break;
+
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ break;
+ mutex_lock(&pinst->lock);
+ err = __padata_remove_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+ if (err)
+ return NOTIFY_BAD;
+ break;
+
+ case CPU_UP_CANCELED:
+ case CPU_UP_CANCELED_FROZEN:
+ if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ break;
+ mutex_lock(&pinst->lock);
+ __padata_remove_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
+ if (!cpumask_test_cpu(cpu, pinst->cpumask))
+ break;
+ mutex_lock(&pinst->lock);
+ __padata_add_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+ }
+
+ return NOTIFY_OK;
+}
+
+/*
+ * padata_alloc - allocate and initialize a padata instance
+ *
+ * @cpumask: cpumask that padata uses for parallelization
+ * @wq: workqueue to use for the allocated padata instance
+ */
+struct padata_instance *padata_alloc(const struct cpumask *cpumask,
+ struct workqueue_struct *wq)
+{
+ int err;
+ struct padata_instance *pinst;
+ struct parallel_data *pd;
+
+ pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
+ if (!pinst)
+ goto err;
+
+ pd = padata_alloc_pd(pinst, cpumask);
+ if (!pd)
+ goto err_free_inst;
+
+ rcu_assign_pointer(pinst->pd, pd);
+
+ pinst->wq = wq;
+
+ cpumask_copy(pinst->cpumask, cpumask);
+
+ pinst->flags = 0;
+
+ pinst->cpu_notifier.notifier_call = padata_cpu_callback;
+ pinst->cpu_notifier.priority = 0;
+ err = register_hotcpu_notifier(&pinst->cpu_notifier);
+ if (err)
+ goto err_free_pd;
+
+ mutex_init(&pinst->lock);
+
+ return pinst;
+
+err_free_pd:
+ padata_free_pd(pd);
+err_free_inst:
+ kfree(pinst);
+err:
+ return NULL;
+}
+EXPORT_SYMBOL(padata_alloc);
+
+/*
+ * padata_free - free a padata instance
+ *
+ * @ padata_inst: padata instance to free
+ */
+void padata_free(struct padata_instance *pinst)
+{
+ padata_stop(pinst);
+
+ synchronize_rcu();
+
+ while (atomic_read(&pinst->pd->refcnt) != 0)
+ yield();
+
+ unregister_hotcpu_notifier(&pinst->cpu_notifier);
+ padata_free_pd(pinst->pd);
+ kfree(pinst);
+}
+EXPORT_SYMBOL(padata_free);
diff --git a/kernel/pid.c b/kernel/pid.c
index 2e17c9c92cbe..b08e697cd83f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -367,7 +367,7 @@ struct task_struct *pid_task(struct pid *pid, enum pid_type type)
struct task_struct *result = NULL;
if (pid) {
struct hlist_node *first;
- first = rcu_dereference(pid->tasks[type].first);
+ first = rcu_dereference_check(pid->tasks[type].first, rcu_read_lock_held() || lockdep_is_held(&tasklist_lock));
if (first)
result = hlist_entry(first, struct task_struct, pids[(type)].node);
}
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 91e09d3b2eb2..5c36ea9d55d2 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -27,6 +27,15 @@ config PM_DEBUG
code. This is helpful when debugging and reporting PM bugs, like
suspend support.
+config PM_ADVANCED_DEBUG
+ bool "Extra PM attributes in sysfs for low-level debugging/testing"
+ depends on PM_DEBUG
+ default n
+ ---help---
+ Add extra sysfs attributes allowing one to access some Power Management
+ fields of device objects from user space. If you are not a kernel
+ developer interested in debugging/testing Power Management, say "no".
+
config PM_VERBOSE
bool "Verbose Power Management debugging"
depends on PM_DEBUG
@@ -85,6 +94,11 @@ config PM_SLEEP
depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE
default y
+config PM_SLEEP_ADVANCED_DEBUG
+ bool
+ depends on PM_ADVANCED_DEBUG
+ default n
+
config SUSPEND
bool "Suspend to RAM and standby"
depends on PM && ARCH_SUSPEND_POSSIBLE
@@ -222,3 +236,8 @@ config PM_RUNTIME
and the bus type drivers of the buses the devices are on are
responsible for the actual handling of the autosuspend requests and
wake-up events.
+
+config PM_OPS
+ bool
+ depends on PM_SLEEP || PM_RUNTIME
+ default y
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 0998c7139053..b58800b21fc0 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -44,6 +44,32 @@ int pm_notifier_call_chain(unsigned long val)
== NOTIFY_BAD) ? -EINVAL : 0;
}
+/* If set, devices may be suspended and resumed asynchronously. */
+int pm_async_enabled = 1;
+
+static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%d\n", pm_async_enabled);
+}
+
+static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ unsigned long val;
+
+ if (strict_strtoul(buf, 10, &val))
+ return -EINVAL;
+
+ if (val > 1)
+ return -EINVAL;
+
+ pm_async_enabled = val;
+ return n;
+}
+
+power_attr(pm_async);
+
#ifdef CONFIG_PM_DEBUG
int pm_test_level = TEST_NONE;
@@ -208,9 +234,12 @@ static struct attribute * g[] = {
#ifdef CONFIG_PM_TRACE
&pm_trace_attr.attr,
#endif
-#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
+#ifdef CONFIG_PM_SLEEP
+ &pm_async_attr.attr,
+#ifdef CONFIG_PM_DEBUG
&pm_test_attr.attr,
#endif
+#endif
NULL,
};
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 36cb168e4330..830cadecbdfc 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1181,7 +1181,7 @@ static void free_unnecessary_pages(void)
memory_bm_position_reset(&copy_bm);
- while (to_free_normal > 0 && to_free_highmem > 0) {
+ while (to_free_normal > 0 || to_free_highmem > 0) {
unsigned long pfn = memory_bm_next_pfn(&copy_bm);
struct page *page = pfn_to_page(pfn);
@@ -1500,7 +1500,7 @@ asmlinkage int swsusp_save(void)
{
unsigned int nr_pages, nr_highmem;
- printk(KERN_INFO "PM: Creating hibernation image: \n");
+ printk(KERN_INFO "PM: Creating hibernation image:\n");
drain_local_pages(NULL);
nr_pages = count_data_pages();
diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 09b2b0ae9e9d..1d575733d4e1 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -657,10 +657,6 @@ int swsusp_read(unsigned int *flags_p)
struct swsusp_info *header;
*flags_p = swsusp_header->flags;
- if (IS_ERR(resume_bdev)) {
- pr_debug("PM: Image device not initialised\n");
- return PTR_ERR(resume_bdev);
- }
memset(&snapshot, 0, sizeof(struct snapshot_handle));
error = snapshot_write_next(&snapshot, PAGE_SIZE);
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
deleted file mode 100644
index 5b3601bd1893..000000000000
--- a/kernel/power/swsusp.c
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * linux/kernel/power/swsusp.c
- *
- * This file provides code to write suspend image to swap and read it back.
- *
- * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
- * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
- *
- * This file is released under the GPLv2.
- *
- * I'd like to thank the following people for their work:
- *
- * Pavel Machek <pavel@ucw.cz>:
- * Modifications, defectiveness pointing, being with me at the very beginning,
- * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
- *
- * Steve Doddi <dirk@loth.demon.co.uk>:
- * Support the possibility of hardware state restoring.
- *
- * Raph <grey.havens@earthling.net>:
- * Support for preserving states of network devices and virtual console
- * (including X and svgatextmode)
- *
- * Kurt Garloff <garloff@suse.de>:
- * Straightened the critical function in order to prevent compilers from
- * playing tricks with local variables.
- *
- * Andreas Mohr <a.mohr@mailto.de>
- *
- * Alex Badea <vampire@go.ro>:
- * Fixed runaway init
- *
- * Rafael J. Wysocki <rjw@sisk.pl>
- * Reworked the freeing of memory and the handling of swap
- *
- * More state savers are welcome. Especially for the scsi layer...
- *
- * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
- */
-
-#include <linux/mm.h>
-#include <linux/suspend.h>
-#include <linux/spinlock.h>
-#include <linux/kernel.h>
-#include <linux/major.h>
-#include <linux/swap.h>
-#include <linux/pm.h>
-#include <linux/swapops.h>
-#include <linux/bootmem.h>
-#include <linux/syscalls.h>
-#include <linux/highmem.h>
-#include <linux/time.h>
-#include <linux/rbtree.h>
-#include <linux/io.h>
-
-#include "power.h"
-
-int in_suspend __nosavedata = 0;
diff --git a/kernel/power/user.c b/kernel/power/user.c
index bf0014d6a5f0..4d2289626a84 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -195,6 +195,15 @@ static ssize_t snapshot_write(struct file *filp, const char __user *buf,
return res;
}
+static void snapshot_deprecated_ioctl(unsigned int cmd)
+{
+ if (printk_ratelimit())
+ printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
+ "be removed soon, update your suspend-to-disk "
+ "utilities\n",
+ __builtin_return_address(0), cmd);
+}
+
static long snapshot_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
@@ -246,8 +255,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
data->frozen = 0;
break;
- case SNAPSHOT_CREATE_IMAGE:
case SNAPSHOT_ATOMIC_SNAPSHOT:
+ snapshot_deprecated_ioctl(cmd);
+ case SNAPSHOT_CREATE_IMAGE:
if (data->mode != O_RDONLY || !data->frozen || data->ready) {
error = -EPERM;
break;
@@ -275,8 +285,9 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
data->ready = 0;
break;
- case SNAPSHOT_PREF_IMAGE_SIZE:
case SNAPSHOT_SET_IMAGE_SIZE:
+ snapshot_deprecated_ioctl(cmd);
+ case SNAPSHOT_PREF_IMAGE_SIZE:
image_size = arg;
break;
@@ -290,15 +301,17 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
error = put_user(size, (loff_t __user *)arg);
break;
- case SNAPSHOT_AVAIL_SWAP_SIZE:
case SNAPSHOT_AVAIL_SWAP:
+ snapshot_deprecated_ioctl(cmd);
+ case SNAPSHOT_AVAIL_SWAP_SIZE:
size = count_swap_pages(data->swap, 1);
size <<= PAGE_SHIFT;
error = put_user(size, (loff_t __user *)arg);
break;
- case SNAPSHOT_ALLOC_SWAP_PAGE:
case SNAPSHOT_GET_SWAP_PAGE:
+ snapshot_deprecated_ioctl(cmd);
+ case SNAPSHOT_ALLOC_SWAP_PAGE:
if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
error = -ENODEV;
break;
@@ -321,6 +334,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
+ snapshot_deprecated_ioctl(cmd);
if (!swsusp_swap_in_use()) {
/*
* User space encodes device types as two-byte values,
@@ -362,6 +376,7 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
+ snapshot_deprecated_ioctl(cmd);
error = -EINVAL;
switch (arg) {
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 9b7fd4723878..f1125c1a6321 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -44,14 +44,43 @@
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/module.h>
+#include <linux/kernel_stat.h>
#ifdef CONFIG_DEBUG_LOCK_ALLOC
static struct lock_class_key rcu_lock_key;
struct lockdep_map rcu_lock_map =
STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
EXPORT_SYMBOL_GPL(rcu_lock_map);
+
+static struct lock_class_key rcu_bh_lock_key;
+struct lockdep_map rcu_bh_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_bh", &rcu_bh_lock_key);
+EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
+
+static struct lock_class_key rcu_sched_lock_key;
+struct lockdep_map rcu_sched_lock_map =
+ STATIC_LOCKDEP_MAP_INIT("rcu_read_lock_sched", &rcu_sched_lock_key);
+EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
#endif
+int rcu_scheduler_active __read_mostly;
+EXPORT_SYMBOL_GPL(rcu_scheduler_active);
+
+/*
+ * This function is invoked towards the end of the scheduler's initialization
+ * process. Before this is called, the idle task might contain
+ * RCU read-side critical sections (during which time, this idle
+ * task is booting the system). After this function is called, the
+ * idle tasks are prohibited from containing RCU read-side critical
+ * sections.
+ */
+void rcu_scheduler_starting(void)
+{
+ WARN_ON(num_online_cpus() != 1);
+ WARN_ON(nr_context_switches() > 0);
+ rcu_scheduler_active = 1;
+}
+
/*
* Awaken the corresponding synchronize_rcu() instance now that a
* grace period has elapsed.
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 9bb52177af02..258cdf0a91eb 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -61,6 +61,9 @@ static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
static int stutter = 5; /* Start/stop testing interval (in sec) */
static int irqreader = 1; /* RCU readers from irq (timers). */
+static int fqs_duration = 0; /* Duration of bursts (us), 0 to disable. */
+static int fqs_holdoff = 0; /* Hold time within burst (us). */
+static int fqs_stutter = 3; /* Wait time between bursts (s). */
static char *torture_type = "rcu"; /* What RCU implementation to torture. */
module_param(nreaders, int, 0444);
@@ -79,6 +82,12 @@ module_param(stutter, int, 0444);
MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test");
module_param(irqreader, int, 0444);
MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers");
+module_param(fqs_duration, int, 0444);
+MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)");
+module_param(fqs_holdoff, int, 0444);
+MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
+module_param(fqs_stutter, int, 0444);
+MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
module_param(torture_type, charp, 0444);
MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
@@ -99,6 +108,7 @@ static struct task_struct **reader_tasks;
static struct task_struct *stats_task;
static struct task_struct *shuffler_task;
static struct task_struct *stutter_task;
+static struct task_struct *fqs_task;
#define RCU_TORTURE_PIPE_LEN 10
@@ -263,6 +273,7 @@ struct rcu_torture_ops {
void (*deferred_free)(struct rcu_torture *p);
void (*sync)(void);
void (*cb_barrier)(void);
+ void (*fqs)(void);
int (*stats)(char *page);
int irq_capable;
char *name;
@@ -347,6 +358,7 @@ static struct rcu_torture_ops rcu_ops = {
.deferred_free = rcu_torture_deferred_free,
.sync = synchronize_rcu,
.cb_barrier = rcu_barrier,
+ .fqs = rcu_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "rcu"
@@ -388,6 +400,7 @@ static struct rcu_torture_ops rcu_sync_ops = {
.deferred_free = rcu_sync_torture_deferred_free,
.sync = synchronize_rcu,
.cb_barrier = NULL,
+ .fqs = rcu_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "rcu_sync"
@@ -403,6 +416,7 @@ static struct rcu_torture_ops rcu_expedited_ops = {
.deferred_free = rcu_sync_torture_deferred_free,
.sync = synchronize_rcu_expedited,
.cb_barrier = NULL,
+ .fqs = rcu_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "rcu_expedited"
@@ -465,6 +479,7 @@ static struct rcu_torture_ops rcu_bh_ops = {
.deferred_free = rcu_bh_torture_deferred_free,
.sync = rcu_bh_torture_synchronize,
.cb_barrier = rcu_barrier_bh,
+ .fqs = rcu_bh_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "rcu_bh"
@@ -480,6 +495,7 @@ static struct rcu_torture_ops rcu_bh_sync_ops = {
.deferred_free = rcu_sync_torture_deferred_free,
.sync = rcu_bh_torture_synchronize,
.cb_barrier = NULL,
+ .fqs = rcu_bh_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "rcu_bh_sync"
@@ -621,6 +637,7 @@ static struct rcu_torture_ops sched_ops = {
.deferred_free = rcu_sched_torture_deferred_free,
.sync = sched_torture_synchronize,
.cb_barrier = rcu_barrier_sched,
+ .fqs = rcu_sched_force_quiescent_state,
.stats = NULL,
.irq_capable = 1,
.name = "sched"
@@ -636,6 +653,7 @@ static struct rcu_torture_ops sched_sync_ops = {
.deferred_free = rcu_sync_torture_deferred_free,
.sync = sched_torture_synchronize,
.cb_barrier = NULL,
+ .fqs = rcu_sched_force_quiescent_state,
.stats = NULL,
.name = "sched_sync"
};
@@ -650,12 +668,45 @@ static struct rcu_torture_ops sched_expedited_ops = {
.deferred_free = rcu_sync_torture_deferred_free,
.sync = synchronize_sched_expedited,
.cb_barrier = NULL,
+ .fqs = rcu_sched_force_quiescent_state,
.stats = rcu_expedited_torture_stats,
.irq_capable = 1,
.name = "sched_expedited"
};
/*
+ * RCU torture force-quiescent-state kthread. Repeatedly induces
+ * bursts of calls to force_quiescent_state(), increasing the probability
+ * of occurrence of some important types of race conditions.
+ */
+static int
+rcu_torture_fqs(void *arg)
+{
+ unsigned long fqs_resume_time;
+ int fqs_burst_remaining;
+
+ VERBOSE_PRINTK_STRING("rcu_torture_fqs task started");
+ do {
+ fqs_resume_time = jiffies + fqs_stutter * HZ;
+ while (jiffies - fqs_resume_time > LONG_MAX) {
+ schedule_timeout_interruptible(1);
+ }
+ fqs_burst_remaining = fqs_duration;
+ while (fqs_burst_remaining > 0) {
+ cur_ops->fqs();
+ udelay(fqs_holdoff);
+ fqs_burst_remaining -= fqs_holdoff;
+ }
+ rcu_stutter_wait("rcu_torture_fqs");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
+ VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping");
+ rcutorture_shutdown_absorb("rcu_torture_fqs");
+ while (!kthread_should_stop())
+ schedule_timeout_uninterruptible(1);
+ return 0;
+}
+
+/*
* RCU torture writer kthread. Repeatedly substitutes a new structure
* for that pointed to by rcu_torture_current, freeing the old structure
* after a series of grace periods (the "pipeline").
@@ -745,7 +796,11 @@ static void rcu_torture_timer(unsigned long unused)
idx = cur_ops->readlock();
completed = cur_ops->completed();
- p = rcu_dereference(rcu_torture_current);
+ p = rcu_dereference_check(rcu_torture_current,
+ rcu_read_lock_held() ||
+ rcu_read_lock_bh_held() ||
+ rcu_read_lock_sched_held() ||
+ srcu_read_lock_held(&srcu_ctl));
if (p == NULL) {
/* Leave because rcu_torture_writer is not yet underway */
cur_ops->readunlock(idx);
@@ -798,11 +853,15 @@ rcu_torture_reader(void *arg)
do {
if (irqreader && cur_ops->irq_capable) {
if (!timer_pending(&t))
- mod_timer(&t, 1);
+ mod_timer(&t, jiffies + 1);
}
idx = cur_ops->readlock();
completed = cur_ops->completed();
- p = rcu_dereference(rcu_torture_current);
+ p = rcu_dereference_check(rcu_torture_current,
+ rcu_read_lock_held() ||
+ rcu_read_lock_bh_held() ||
+ rcu_read_lock_sched_held() ||
+ srcu_read_lock_held(&srcu_ctl));
if (p == NULL) {
/* Wait for rcu_torture_writer to get underway */
cur_ops->readunlock(idx);
@@ -1030,10 +1089,11 @@ rcu_torture_print_module_parms(char *tag)
printk(KERN_ALERT "%s" TORTURE_FLAG
"--- %s: nreaders=%d nfakewriters=%d "
"stat_interval=%d verbose=%d test_no_idle_hz=%d "
- "shuffle_interval=%d stutter=%d irqreader=%d\n",
+ "shuffle_interval=%d stutter=%d irqreader=%d "
+ "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d\n",
torture_type, tag, nrealreaders, nfakewriters,
stat_interval, verbose, test_no_idle_hz, shuffle_interval,
- stutter, irqreader);
+ stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter);
}
static struct notifier_block rcutorture_nb = {
@@ -1109,6 +1169,12 @@ rcu_torture_cleanup(void)
}
stats_task = NULL;
+ if (fqs_task) {
+ VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task");
+ kthread_stop(fqs_task);
+ }
+ fqs_task = NULL;
+
/* Wait for all RCU callbacks to fire. */
if (cur_ops->cb_barrier != NULL)
@@ -1154,6 +1220,11 @@ rcu_torture_init(void)
mutex_unlock(&fullstop_mutex);
return -EINVAL;
}
+ if (cur_ops->fqs == NULL && fqs_duration != 0) {
+ printk(KERN_ALERT "rcu-torture: ->fqs NULL and non-zero "
+ "fqs_duration, fqs disabled.\n");
+ fqs_duration = 0;
+ }
if (cur_ops->init)
cur_ops->init(); /* no "goto unwind" prior to this point!!! */
@@ -1282,6 +1353,19 @@ rcu_torture_init(void)
goto unwind;
}
}
+ if (fqs_duration < 0)
+ fqs_duration = 0;
+ if (fqs_duration) {
+ /* Create the stutter thread */
+ fqs_task = kthread_run(rcu_torture_fqs, NULL,
+ "rcu_torture_fqs");
+ if (IS_ERR(fqs_task)) {
+ firsterr = PTR_ERR(fqs_task);
+ VERBOSE_PRINTK_ERRSTRING("Failed to create fqs");
+ fqs_task = NULL;
+ goto unwind;
+ }
+ }
register_reboot_notifier(&rcutorture_nb);
mutex_unlock(&fullstop_mutex);
return 0;
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 53ae9598f798..3ec8160fc75f 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -46,7 +46,6 @@
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/time.h>
-#include <linux/kernel_stat.h>
#include "rcutree.h"
@@ -66,11 +65,11 @@ static struct lock_class_key rcu_node_class[NUM_RCU_LVLS];
.signaled = RCU_GP_IDLE, \
.gpnum = -300, \
.completed = -300, \
- .onofflock = __SPIN_LOCK_UNLOCKED(&name.onofflock), \
+ .onofflock = __RAW_SPIN_LOCK_UNLOCKED(&name.onofflock), \
.orphan_cbs_list = NULL, \
.orphan_cbs_tail = &name.orphan_cbs_list, \
.orphan_qlen = 0, \
- .fqslock = __SPIN_LOCK_UNLOCKED(&name.fqslock), \
+ .fqslock = __RAW_SPIN_LOCK_UNLOCKED(&name.fqslock), \
.n_force_qs = 0, \
.n_force_qs_ngp = 0, \
}
@@ -81,9 +80,6 @@ DEFINE_PER_CPU(struct rcu_data, rcu_sched_data);
struct rcu_state rcu_bh_state = RCU_STATE_INITIALIZER(rcu_bh_state);
DEFINE_PER_CPU(struct rcu_data, rcu_bh_data);
-static int rcu_scheduler_active __read_mostly;
-
-
/*
* Return true if an RCU grace period is in progress. The ACCESS_ONCE()s
* permit this function to be invoked without holding the root rcu_node
@@ -157,6 +153,24 @@ long rcu_batches_completed_bh(void)
EXPORT_SYMBOL_GPL(rcu_batches_completed_bh);
/*
+ * Force a quiescent state for RCU BH.
+ */
+void rcu_bh_force_quiescent_state(void)
+{
+ force_quiescent_state(&rcu_bh_state, 0);
+}
+EXPORT_SYMBOL_GPL(rcu_bh_force_quiescent_state);
+
+/*
+ * Force a quiescent state for RCU-sched.
+ */
+void rcu_sched_force_quiescent_state(void)
+{
+ force_quiescent_state(&rcu_sched_state, 0);
+}
+EXPORT_SYMBOL_GPL(rcu_sched_force_quiescent_state);
+
+/*
* Does the CPU have callbacks ready to be invoked?
*/
static int
@@ -439,10 +453,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
/* Only let one CPU complain about others per time interval. */
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
delta = jiffies - rsp->jiffies_stall;
if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) {
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
rsp->jiffies_stall = jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
@@ -452,13 +466,15 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
* due to CPU offlining.
*/
rcu_print_task_stall(rnp);
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
/* OK, time to rat on our buddy... */
printk(KERN_ERR "INFO: RCU detected CPU stalls:");
rcu_for_each_leaf_node(rsp, rnp) {
+ raw_spin_lock_irqsave(&rnp->lock, flags);
rcu_print_task_stall(rnp);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
if (rnp->qsmask == 0)
continue;
for (cpu = 0; cpu <= rnp->grphi - rnp->grplo; cpu++)
@@ -469,6 +485,10 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
smp_processor_id(), (long)(jiffies - rsp->gp_start));
trigger_all_cpu_backtrace();
+ /* If so configured, complain about tasks blocking the grace period. */
+
+ rcu_print_detail_task_stall(rsp);
+
force_quiescent_state(rsp, 0); /* Kick them all. */
}
@@ -481,11 +501,11 @@ static void print_cpu_stall(struct rcu_state *rsp)
smp_processor_id(), jiffies - rsp->gp_start);
trigger_all_cpu_backtrace();
- spin_lock_irqsave(&rnp->lock, flags);
- if ((long)(jiffies - rsp->jiffies_stall) >= 0)
+ raw_spin_lock_irqsave(&rnp->lock, flags);
+ if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall))
rsp->jiffies_stall =
jiffies + RCU_SECONDS_TILL_STALL_RECHECK;
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
set_need_resched(); /* kick ourselves to get things going. */
}
@@ -545,12 +565,12 @@ static void note_new_gpnum(struct rcu_state *rsp, struct rcu_data *rdp)
local_irq_save(flags);
rnp = rdp->mynode;
if (rdp->gpnum == ACCESS_ONCE(rnp->gpnum) || /* outside lock. */
- !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */
+ !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */
local_irq_restore(flags);
return;
}
__note_new_gpnum(rsp, rnp, rdp);
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
@@ -609,12 +629,12 @@ rcu_process_gp_end(struct rcu_state *rsp, struct rcu_data *rdp)
local_irq_save(flags);
rnp = rdp->mynode;
if (rdp->completed == ACCESS_ONCE(rnp->completed) || /* outside lock. */
- !spin_trylock(&rnp->lock)) { /* irqs already off, retry later. */
+ !raw_spin_trylock(&rnp->lock)) { /* irqs already off, so later. */
local_irq_restore(flags);
return;
}
__rcu_process_gp_end(rsp, rnp, rdp);
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
@@ -659,12 +679,14 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
struct rcu_data *rdp = rsp->rda[smp_processor_id()];
struct rcu_node *rnp = rcu_get_root(rsp);
- if (!cpu_needs_another_gp(rsp, rdp)) {
+ if (!cpu_needs_another_gp(rsp, rdp) || rsp->fqs_active) {
+ if (cpu_needs_another_gp(rsp, rdp))
+ rsp->fqs_need_gp = 1;
if (rnp->completed == rsp->completed) {
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
/*
* Propagate new ->completed value to rcu_node structures
@@ -672,9 +694,9 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
* of the next grace period to process their callbacks.
*/
rcu_for_each_node_breadth_first(rsp, rnp) {
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
rnp->completed = rsp->completed;
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
local_irq_restore(flags);
return;
@@ -695,15 +717,15 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
rnp->completed = rsp->completed;
rsp->signaled = RCU_SIGNAL_INIT; /* force_quiescent_state OK. */
rcu_start_gp_per_cpu(rsp, rnp, rdp);
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
- spin_unlock(&rnp->lock); /* leave irqs disabled. */
+ raw_spin_unlock(&rnp->lock); /* leave irqs disabled. */
/* Exclude any concurrent CPU-hotplug operations. */
- spin_lock(&rsp->onofflock); /* irqs already disabled. */
+ raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */
/*
* Set the quiescent-state-needed bits in all the rcu_node
@@ -723,21 +745,21 @@ 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. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
rcu_preempt_check_blocked_tasks(rnp);
rnp->qsmask = rnp->qsmaskinit;
rnp->gpnum = rsp->gpnum;
rnp->completed = rsp->completed;
if (rnp == rdp->mynode)
rcu_start_gp_per_cpu(rsp, rnp, rdp);
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
rnp = rcu_get_root(rsp);
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_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);
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
}
/*
@@ -776,14 +798,14 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
if (!(rnp->qsmask & mask)) {
/* Our bit has already been cleared, so done. */
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
rnp->qsmask &= ~mask;
if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {
/* Other bits still set at this level, so done. */
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
mask = rnp->grpmask;
@@ -793,10 +815,10 @@ rcu_report_qs_rnp(unsigned long mask, struct rcu_state *rsp,
break;
}
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
rnp_c = rnp;
rnp = rnp->parent;
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
WARN_ON_ONCE(rnp_c->qsmask);
}
@@ -825,7 +847,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las
struct rcu_node *rnp;
rnp = rdp->mynode;
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
if (lastcomp != rnp->completed) {
/*
@@ -837,12 +859,12 @@ rcu_report_qs_rdp(int cpu, struct rcu_state *rsp, struct rcu_data *rdp, long las
* race occurred.
*/
rdp->passed_quiesc = 0; /* try again later! */
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return;
}
mask = rdp->grpmask;
if ((rnp->qsmask & mask) == 0) {
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
} else {
rdp->qs_pending = 0;
@@ -906,7 +928,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
if (rdp->nxtlist == NULL)
return; /* irqs disabled, so comparison is stable. */
- spin_lock(&rsp->onofflock); /* irqs already disabled. */
+ raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */
*rsp->orphan_cbs_tail = rdp->nxtlist;
rsp->orphan_cbs_tail = rdp->nxttail[RCU_NEXT_TAIL];
rdp->nxtlist = NULL;
@@ -914,7 +936,7 @@ static void rcu_send_cbs_to_orphanage(struct rcu_state *rsp)
rdp->nxttail[i] = &rdp->nxtlist;
rsp->orphan_qlen += rdp->qlen;
rdp->qlen = 0;
- spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
+ raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
}
/*
@@ -925,10 +947,10 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
unsigned long flags;
struct rcu_data *rdp;
- spin_lock_irqsave(&rsp->onofflock, flags);
+ raw_spin_lock_irqsave(&rsp->onofflock, flags);
rdp = rsp->rda[smp_processor_id()];
if (rsp->orphan_cbs_list == NULL) {
- spin_unlock_irqrestore(&rsp->onofflock, flags);
+ raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
return;
}
*rdp->nxttail[RCU_NEXT_TAIL] = rsp->orphan_cbs_list;
@@ -937,7 +959,7 @@ static void rcu_adopt_orphan_cbs(struct rcu_state *rsp)
rsp->orphan_cbs_list = NULL;
rsp->orphan_cbs_tail = &rsp->orphan_cbs_list;
rsp->orphan_qlen = 0;
- spin_unlock_irqrestore(&rsp->onofflock, flags);
+ raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
}
/*
@@ -953,23 +975,23 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
struct rcu_node *rnp;
/* Exclude any attempts to start a new grace period. */
- spin_lock_irqsave(&rsp->onofflock, flags);
+ raw_spin_lock_irqsave(&rsp->onofflock, flags);
/* Remove the outgoing CPU from the masks in the rcu_node hierarchy. */
rnp = rdp->mynode; /* this is the outgoing CPU's rnp. */
mask = rdp->grpmask; /* rnp->grplo is constant. */
do {
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
rnp->qsmaskinit &= ~mask;
if (rnp->qsmaskinit != 0) {
if (rnp != rdp->mynode)
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
break;
}
if (rnp == rdp->mynode)
need_report = rcu_preempt_offline_tasks(rsp, rnp, rdp);
else
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
mask = rnp->grpmask;
rnp = rnp->parent;
} while (rnp != NULL);
@@ -980,12 +1002,12 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
* because invoking rcu_report_unblock_qs_rnp() with ->onofflock
* held leads to deadlock.
*/
- spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
+ raw_spin_unlock(&rsp->onofflock); /* irqs remain disabled. */
rnp = rdp->mynode;
if (need_report & RCU_OFL_TASKS_NORM_GP)
rcu_report_unblock_qs_rnp(rnp, flags);
else
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
if (need_report & RCU_OFL_TASKS_EXP_GP)
rcu_report_exp_rnp(rsp, rnp);
@@ -1144,11 +1166,9 @@ void rcu_check_callbacks(int cpu, int user)
/*
* Scan the leaf rcu_node structures, processing dyntick state for any that
* have not yet encountered a quiescent state, using the function specified.
- * Returns 1 if the current grace period ends while scanning (possibly
- * because we made it end).
+ * The caller must have suppressed start of new grace periods.
*/
-static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
- int (*f)(struct rcu_data *))
+static void force_qs_rnp(struct rcu_state *rsp, int (*f)(struct rcu_data *))
{
unsigned long bit;
int cpu;
@@ -1158,13 +1178,13 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
rcu_for_each_leaf_node(rsp, rnp) {
mask = 0;
- spin_lock_irqsave(&rnp->lock, flags);
- if (rnp->completed != lastcomp) {
- spin_unlock_irqrestore(&rnp->lock, flags);
- return 1;
+ raw_spin_lock_irqsave(&rnp->lock, flags);
+ if (!rcu_gp_in_progress(rsp)) {
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ return;
}
if (rnp->qsmask == 0) {
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
continue;
}
cpu = rnp->grplo;
@@ -1173,15 +1193,14 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
if ((rnp->qsmask & bit) != 0 && f(rsp->rda[cpu]))
mask |= bit;
}
- if (mask != 0 && rnp->completed == lastcomp) {
+ if (mask != 0) {
/* rcu_report_qs_rnp() releases rnp->lock. */
rcu_report_qs_rnp(mask, rsp, rnp, flags);
continue;
}
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
- return 0;
}
/*
@@ -1191,32 +1210,26 @@ static int rcu_process_dyntick(struct rcu_state *rsp, long lastcomp,
static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
{
unsigned long flags;
- long lastcomp;
struct rcu_node *rnp = rcu_get_root(rsp);
- u8 signaled;
- u8 forcenow;
if (!rcu_gp_in_progress(rsp))
return; /* No grace period in progress, nothing to force. */
- if (!spin_trylock_irqsave(&rsp->fqslock, flags)) {
+ if (!raw_spin_trylock_irqsave(&rsp->fqslock, flags)) {
rsp->n_force_qs_lh++; /* Inexact, can lose counts. Tough! */
return; /* Someone else is already on the job. */
}
- if (relaxed &&
- (long)(rsp->jiffies_force_qs - jiffies) >= 0)
- goto unlock_ret; /* no emergency and done recently. */
+ if (relaxed && ULONG_CMP_GE(rsp->jiffies_force_qs, jiffies))
+ goto unlock_fqs_ret; /* no emergency and done recently. */
rsp->n_force_qs++;
- spin_lock(&rnp->lock);
- lastcomp = rsp->gpnum - 1;
- signaled = rsp->signaled;
+ raw_spin_lock(&rnp->lock); /* irqs already disabled */
rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
if(!rcu_gp_in_progress(rsp)) {
rsp->n_force_qs_ngp++;
- spin_unlock(&rnp->lock);
- goto unlock_ret; /* no GP in progress, time updated. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
+ goto unlock_fqs_ret; /* no GP in progress, time updated. */
}
- spin_unlock(&rnp->lock);
- switch (signaled) {
+ rsp->fqs_active = 1;
+ switch (rsp->signaled) {
case RCU_GP_IDLE:
case RCU_GP_INIT:
@@ -1224,45 +1237,38 @@ static void force_quiescent_state(struct rcu_state *rsp, int relaxed)
case RCU_SAVE_DYNTICK:
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
if (RCU_SIGNAL_INIT != RCU_SAVE_DYNTICK)
break; /* So gcc recognizes the dead code. */
/* Record dyntick-idle state. */
- if (rcu_process_dyntick(rsp, lastcomp,
- dyntick_save_progress_counter))
- goto unlock_ret;
- /* fall into next case. */
-
- case RCU_SAVE_COMPLETED:
-
- /* Update state, record completion counter. */
- forcenow = 0;
- spin_lock(&rnp->lock);
- if (lastcomp + 1 == rsp->gpnum &&
- lastcomp == rsp->completed &&
- rsp->signaled == signaled) {
+ force_qs_rnp(rsp, dyntick_save_progress_counter);
+ raw_spin_lock(&rnp->lock); /* irqs already disabled */
+ if (rcu_gp_in_progress(rsp))
rsp->signaled = RCU_FORCE_QS;
- rsp->completed_fqs = lastcomp;
- forcenow = signaled == RCU_SAVE_COMPLETED;
- }
- spin_unlock(&rnp->lock);
- if (!forcenow)
- break;
- /* fall into next case. */
+ break;
case RCU_FORCE_QS:
/* Check dyntick-idle state, send IPI to laggarts. */
- if (rcu_process_dyntick(rsp, rsp->completed_fqs,
- rcu_implicit_dynticks_qs))
- goto unlock_ret;
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
+ force_qs_rnp(rsp, rcu_implicit_dynticks_qs);
/* Leave state in case more forcing is required. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled */
break;
}
-unlock_ret:
- spin_unlock_irqrestore(&rsp->fqslock, flags);
+ rsp->fqs_active = 0;
+ if (rsp->fqs_need_gp) {
+ raw_spin_unlock(&rsp->fqslock); /* irqs remain disabled */
+ rsp->fqs_need_gp = 0;
+ rcu_start_gp(rsp, flags); /* releases rnp->lock */
+ return;
+ }
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
+unlock_fqs_ret:
+ raw_spin_unlock_irqrestore(&rsp->fqslock, flags);
}
#else /* #ifdef CONFIG_SMP */
@@ -1290,7 +1296,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
* If an RCU GP has gone long enough, go check for dyntick
* idle CPUs and, if needed, send resched IPIs.
*/
- if ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)
+ if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies))
force_quiescent_state(rsp, 1);
/*
@@ -1304,7 +1310,7 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
/* Does this CPU require a not-yet-started grace period? */
if (cpu_needs_another_gp(rsp, rdp)) {
- spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
+ raw_spin_lock_irqsave(&rcu_get_root(rsp)->lock, flags);
rcu_start_gp(rsp, flags); /* releases above lock */
}
@@ -1335,6 +1341,9 @@ static void rcu_process_callbacks(struct softirq_action *unused)
* grace-period manipulations above.
*/
smp_mb(); /* See above block comment. */
+
+ /* If we are last CPU on way to dyntick-idle mode, accelerate it. */
+ rcu_needs_cpu_flush();
}
static void
@@ -1369,7 +1378,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
unsigned long nestflag;
struct rcu_node *rnp_root = rcu_get_root(rsp);
- spin_lock_irqsave(&rnp_root->lock, nestflag);
+ raw_spin_lock_irqsave(&rnp_root->lock, nestflag);
rcu_start_gp(rsp, nestflag); /* releases rnp_root->lock. */
}
@@ -1387,7 +1396,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
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)
+ } else if (ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies))
force_quiescent_state(rsp, 1);
local_irq_restore(flags);
}
@@ -1520,7 +1529,7 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp)
/* Has an RCU GP gone long enough to send resched IPIs &c? */
if (rcu_gp_in_progress(rsp) &&
- ((long)(ACCESS_ONCE(rsp->jiffies_force_qs) - jiffies) < 0)) {
+ ULONG_CMP_LT(ACCESS_ONCE(rsp->jiffies_force_qs), jiffies)) {
rdp->n_rp_need_fqs++;
return 1;
}
@@ -1545,10 +1554,9 @@ static int rcu_pending(int cpu)
/*
* Check to see if any future RCU-related work will need to be done
* by the current CPU, even if none need be done immediately, returning
- * 1 if so. This function is part of the RCU implementation; it is -not-
- * an exported member of the RCU API.
+ * 1 if so.
*/
-int rcu_needs_cpu(int cpu)
+static int rcu_needs_cpu_quick_check(int cpu)
{
/* RCU callbacks either ready or pending? */
return per_cpu(rcu_sched_data, cpu).nxtlist ||
@@ -1556,21 +1564,6 @@ int rcu_needs_cpu(int cpu)
rcu_preempt_needs_cpu(cpu);
}
-/*
- * This function is invoked towards the end of the scheduler's initialization
- * process. Before this is called, the idle task might contain
- * RCU read-side critical sections (during which time, this idle
- * task is booting the system). After this function is called, the
- * idle tasks are prohibited from containing RCU read-side critical
- * sections.
- */
-void rcu_scheduler_starting(void)
-{
- WARN_ON(num_online_cpus() != 1);
- WARN_ON(nr_context_switches() > 0);
- rcu_scheduler_active = 1;
-}
-
static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
static atomic_t rcu_barrier_cpu_count;
static DEFINE_MUTEX(rcu_barrier_mutex);
@@ -1659,7 +1652,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
struct rcu_node *rnp = rcu_get_root(rsp);
/* Set up local state, ensuring consistent view of global state. */
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
rdp->grpmask = 1UL << (cpu - rdp->mynode->grplo);
rdp->nxtlist = NULL;
for (i = 0; i < RCU_NEXT_SIZE; i++)
@@ -1669,7 +1662,7 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
#endif /* #ifdef CONFIG_NO_HZ */
rdp->cpu = cpu;
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
@@ -1687,7 +1680,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
struct rcu_node *rnp = rcu_get_root(rsp);
/* Set up local state, ensuring consistent view of global state. */
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
rdp->passed_quiesc = 0; /* We could be racing with new GP, */
rdp->qs_pending = 1; /* so set up to respond to current GP. */
rdp->beenonline = 1; /* We have now been online. */
@@ -1695,7 +1688,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
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. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
/*
* A new grace period might start here. If so, we won't be part
@@ -1703,14 +1696,14 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
*/
/* Exclude any attempts to start a new GP on large systems. */
- spin_lock(&rsp->onofflock); /* irqs already disabled. */
+ raw_spin_lock(&rsp->onofflock); /* irqs already disabled. */
/* Add CPU to rcu_node bitmasks. */
rnp = rdp->mynode;
mask = rdp->grpmask;
do {
/* Exclude any attempts to start a new GP on small systems. */
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
rnp->qsmaskinit |= mask;
mask = rnp->grpmask;
if (rnp == rdp->mynode) {
@@ -1718,11 +1711,11 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptable)
rdp->completed = rnp->completed;
rdp->passed_quiesc_completed = rnp->completed - 1;
}
- spin_unlock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs already disabled. */
rnp = rnp->parent;
} while (rnp != NULL && !(rnp->qsmaskinit & mask));
- spin_unlock_irqrestore(&rsp->onofflock, flags);
+ raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
}
static void __cpuinit rcu_online_cpu(int cpu)
@@ -1806,11 +1799,17 @@ static void __init rcu_init_levelspread(struct rcu_state *rsp)
*/
static void __init rcu_init_one(struct rcu_state *rsp)
{
+ static char *buf[] = { "rcu_node_level_0",
+ "rcu_node_level_1",
+ "rcu_node_level_2",
+ "rcu_node_level_3" }; /* Match MAX_RCU_LVLS */
int cpustride = 1;
int i;
int j;
struct rcu_node *rnp;
+ BUILD_BUG_ON(MAX_RCU_LVLS > ARRAY_SIZE(buf)); /* Fix buf[] init! */
+
/* Initialize the level-tracking arrays. */
for (i = 1; i < NUM_RCU_LVLS; i++)
@@ -1823,8 +1822,9 @@ static void __init rcu_init_one(struct rcu_state *rsp)
cpustride *= rsp->levelspread[i];
rnp = rsp->level[i];
for (j = 0; j < rsp->levelcnt[i]; j++, rnp++) {
- spin_lock_init(&rnp->lock);
- lockdep_set_class(&rnp->lock, &rcu_node_class[i]);
+ raw_spin_lock_init(&rnp->lock);
+ lockdep_set_class_and_name(&rnp->lock,
+ &rcu_node_class[i], buf[i]);
rnp->gpnum = 0;
rnp->qsmask = 0;
rnp->qsmaskinit = 0;
@@ -1876,7 +1876,7 @@ do { \
void __init rcu_init(void)
{
- int i;
+ int cpu;
rcu_bootup_announce();
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
@@ -1896,8 +1896,8 @@ void __init rcu_init(void)
* or the scheduler are operational.
*/
cpu_notifier(rcu_cpu_notify, 0);
- for_each_online_cpu(i)
- rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)i);
+ for_each_online_cpu(cpu)
+ rcu_cpu_notify(NULL, CPU_UP_PREPARE, (void *)(long)cpu);
}
#include "rcutree_plugin.h"
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index d2a0046f63b2..1439eb504c22 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -90,12 +90,12 @@ struct rcu_dynticks {
* Definition for node within the RCU grace-period-detection hierarchy.
*/
struct rcu_node {
- spinlock_t lock; /* Root rcu_node's lock protects some */
+ raw_spinlock_t lock; /* Root rcu_node's lock protects some */
/* rcu_state fields as well as following. */
- long gpnum; /* Current grace period for this node. */
+ unsigned long gpnum; /* Current grace period for this node. */
/* This will either be equal to or one */
/* behind the root rcu_node's gpnum. */
- long completed; /* Last grace period completed for this node. */
+ unsigned long completed; /* Last GP completed for this node. */
/* This will either be equal to or one */
/* behind the root rcu_node's gpnum. */
unsigned long qsmask; /* CPUs or groups that need to switch in */
@@ -161,11 +161,11 @@ struct rcu_node {
/* Per-CPU data for read-copy update. */
struct rcu_data {
/* 1) quiescent-state and grace-period handling : */
- long completed; /* Track rsp->completed gp number */
+ unsigned long completed; /* Track rsp->completed gp number */
/* in order to detect GP end. */
- long gpnum; /* Highest gp number that this CPU */
+ unsigned long gpnum; /* Highest gp number that this CPU */
/* is aware of having started. */
- long passed_quiesc_completed;
+ unsigned long passed_quiesc_completed;
/* Value of completed at time of qs. */
bool passed_quiesc; /* User-mode/idle loop etc. */
bool qs_pending; /* Core waits for quiesc state. */
@@ -221,14 +221,14 @@ struct rcu_data {
unsigned long resched_ipi; /* Sent a resched IPI. */
/* 5) __rcu_pending() statistics. */
- long n_rcu_pending; /* rcu_pending() calls since boot. */
- long n_rp_qs_pending;
- long n_rp_cb_ready;
- long n_rp_cpu_needs_gp;
- long n_rp_gp_completed;
- long n_rp_gp_started;
- long n_rp_need_fqs;
- long n_rp_need_nothing;
+ unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */
+ unsigned long n_rp_qs_pending;
+ unsigned long n_rp_cb_ready;
+ unsigned long n_rp_cpu_needs_gp;
+ unsigned long n_rp_gp_completed;
+ unsigned long n_rp_gp_started;
+ unsigned long n_rp_need_fqs;
+ unsigned long n_rp_need_nothing;
int cpu;
};
@@ -237,12 +237,11 @@ struct rcu_data {
#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_SAVE_COMPLETED 3 /* Need to save rsp->completed. */
-#define RCU_FORCE_QS 4 /* Need to force quiescent 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 */
-#define RCU_SIGNAL_INIT RCU_SAVE_COMPLETED
+#define RCU_SIGNAL_INIT RCU_FORCE_QS
#endif /* #else #ifdef CONFIG_NO_HZ */
#define RCU_JIFFIES_TILL_FORCE_QS 3 /* for rsp->jiffies_force_qs */
@@ -256,6 +255,9 @@ struct rcu_data {
#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+#define ULONG_CMP_GE(a, b) (ULONG_MAX / 2 >= (a) - (b))
+#define ULONG_CMP_LT(a, b) (ULONG_MAX / 2 < (a) - (b))
+
/*
* RCU global state, including node hierarchy. This hierarchy is
* represented in "heap" form in a dense array. The root (first level)
@@ -277,12 +279,19 @@ struct rcu_state {
u8 signaled ____cacheline_internodealigned_in_smp;
/* Force QS state. */
- long gpnum; /* Current gp number. */
- long completed; /* # of last completed gp. */
+ u8 fqs_active; /* force_quiescent_state() */
+ /* is running. */
+ u8 fqs_need_gp; /* A CPU was prevented from */
+ /* starting a new grace */
+ /* period because */
+ /* force_quiescent_state() */
+ /* was running. */
+ unsigned long gpnum; /* Current gp number. */
+ unsigned long completed; /* # of last completed gp. */
/* End of fields guarded by root rcu_node's lock. */
- spinlock_t onofflock; /* exclude on/offline and */
+ raw_spinlock_t onofflock; /* exclude on/offline and */
/* starting new GP. Also */
/* protects the following */
/* orphan_cbs fields. */
@@ -292,10 +301,8 @@ struct rcu_state {
/* going offline. */
struct rcu_head **orphan_cbs_tail; /* And tail pointer. */
long orphan_qlen; /* Number of orphaned cbs. */
- spinlock_t fqslock; /* Only one task forcing */
+ raw_spinlock_t fqslock; /* Only one task forcing */
/* quiescent states. */
- long completed_fqs; /* Value of completed @ snap. */
- /* Protected by fqslock. */
unsigned long jiffies_force_qs; /* Time at which to invoke */
/* force_quiescent_state(). */
unsigned long n_force_qs; /* Number of calls to */
@@ -319,8 +326,6 @@ struct rcu_state {
#define RCU_OFL_TASKS_EXP_GP 0x2 /* Tasks blocking expedited */
/* GP were moved to root. */
-#ifdef RCU_TREE_NONCORE
-
/*
* RCU implementation internal declarations:
*/
@@ -335,7 +340,7 @@ extern struct rcu_state rcu_preempt_state;
DECLARE_PER_CPU(struct rcu_data, rcu_preempt_data);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
-#else /* #ifdef RCU_TREE_NONCORE */
+#ifndef RCU_TREE_NONCORE
/* Forward declarations for rcutree_plugin.h */
static void rcu_bootup_announce(void);
@@ -347,6 +352,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
unsigned long flags);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+static void rcu_print_detail_task_stall(struct rcu_state *rsp);
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);
@@ -367,5 +373,6 @@ static int rcu_preempt_needs_cpu(int cpu);
static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
static void rcu_preempt_send_cbs_to_orphanage(void);
static void __init __rcu_init_preempt(void);
+static void rcu_needs_cpu_flush(void);
-#endif /* #else #ifdef RCU_TREE_NONCORE */
+#endif /* #ifndef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 37fbccdf41d5..464ad2cdee00 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -62,6 +62,15 @@ long rcu_batches_completed(void)
EXPORT_SYMBOL_GPL(rcu_batches_completed);
/*
+ * Force a quiescent state for preemptible RCU.
+ */
+void rcu_force_quiescent_state(void)
+{
+ force_quiescent_state(&rcu_preempt_state, 0);
+}
+EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
+
+/*
* Record a preemptable-RCU quiescent state for the specified CPU. Note
* that this just means that the task currently running on the CPU is
* not in a quiescent state. There might be any number of tasks blocked
@@ -102,7 +111,7 @@ static void rcu_preempt_note_context_switch(int cpu)
/* Possibly blocking in an RCU read-side critical section. */
rdp = rcu_preempt_state.rda[cpu];
rnp = rdp->mynode;
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
t->rcu_read_unlock_special |= RCU_READ_UNLOCK_BLOCKED;
t->rcu_blocked_node = rnp;
@@ -123,7 +132,7 @@ static void rcu_preempt_note_context_switch(int cpu)
WARN_ON_ONCE(!list_empty(&t->rcu_node_entry));
phase = (rnp->gpnum + !(rnp->qsmask & rdp->grpmask)) & 0x1;
list_add(&t->rcu_node_entry, &rnp->blocked_tasks[phase]);
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
@@ -180,7 +189,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
struct rcu_node *rnp_p;
if (rnp->qsmask != 0 || rcu_preempted_readers(rnp)) {
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
return; /* Still need more quiescent states! */
}
@@ -197,8 +206,8 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
/* Report up the rest of the hierarchy. */
mask = rnp->grpmask;
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
- spin_lock(&rnp_p->lock); /* irqs already disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_lock(&rnp_p->lock); /* irqs already disabled. */
rcu_report_qs_rnp(mask, &rcu_preempt_state, rnp_p, flags);
}
@@ -248,10 +257,10 @@ static void rcu_read_unlock_special(struct task_struct *t)
*/
for (;;) {
rnp = t->rcu_blocked_node;
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
if (rnp == t->rcu_blocked_node)
break;
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
empty = !rcu_preempted_readers(rnp);
empty_exp = !rcu_preempted_readers_exp(rnp);
@@ -265,7 +274,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
* Note that rcu_report_unblock_qs_rnp() releases rnp->lock.
*/
if (empty)
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
else
rcu_report_unblock_qs_rnp(rnp, flags);
@@ -295,29 +304,73 @@ void __rcu_read_unlock(void)
if (--ACCESS_ONCE(t->rcu_read_lock_nesting) == 0 &&
unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
rcu_read_unlock_special(t);
+#ifdef CONFIG_PROVE_LOCKING
+ WARN_ON_ONCE(ACCESS_ONCE(t->rcu_read_lock_nesting) < 0);
+#endif /* #ifdef CONFIG_PROVE_LOCKING */
}
EXPORT_SYMBOL_GPL(__rcu_read_unlock);
#ifdef CONFIG_RCU_CPU_STALL_DETECTOR
+#ifdef CONFIG_RCU_CPU_STALL_VERBOSE
+
+/*
+ * Dump detailed information for all tasks blocking the current RCU
+ * grace period on the specified rcu_node structure.
+ */
+static void rcu_print_detail_task_stall_rnp(struct rcu_node *rnp)
+{
+ unsigned long flags;
+ struct list_head *lp;
+ int phase;
+ struct task_struct *t;
+
+ if (rcu_preempted_readers(rnp)) {
+ raw_spin_lock_irqsave(&rnp->lock, flags);
+ phase = rnp->gpnum & 0x1;
+ lp = &rnp->blocked_tasks[phase];
+ list_for_each_entry(t, lp, rcu_node_entry)
+ sched_show_task(t);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ }
+}
+
+/*
+ * Dump detailed information for all tasks blocking the current RCU
+ * grace period.
+ */
+static void rcu_print_detail_task_stall(struct rcu_state *rsp)
+{
+ struct rcu_node *rnp = rcu_get_root(rsp);
+
+ rcu_print_detail_task_stall_rnp(rnp);
+ rcu_for_each_leaf_node(rsp, rnp)
+ rcu_print_detail_task_stall_rnp(rnp);
+}
+
+#else /* #ifdef CONFIG_RCU_CPU_STALL_VERBOSE */
+
+static void rcu_print_detail_task_stall(struct rcu_state *rsp)
+{
+}
+
+#endif /* #else #ifdef CONFIG_RCU_CPU_STALL_VERBOSE */
+
/*
* Scan the current list of tasks blocked within RCU read-side critical
* sections, printing out the tid of each.
*/
static void rcu_print_task_stall(struct rcu_node *rnp)
{
- unsigned long flags;
struct list_head *lp;
int phase;
struct task_struct *t;
if (rcu_preempted_readers(rnp)) {
- spin_lock_irqsave(&rnp->lock, flags);
phase = rnp->gpnum & 0x1;
lp = &rnp->blocked_tasks[phase];
list_for_each_entry(t, lp, rcu_node_entry)
printk(" P%d", t->pid);
- spin_unlock_irqrestore(&rnp->lock, flags);
}
}
@@ -388,11 +441,11 @@ static int rcu_preempt_offline_tasks(struct rcu_state *rsp,
lp_root = &rnp_root->blocked_tasks[i];
while (!list_empty(lp)) {
tp = list_entry(lp->next, typeof(*tp), rcu_node_entry);
- spin_lock(&rnp_root->lock); /* irqs already disabled */
+ raw_spin_lock(&rnp_root->lock); /* irqs already disabled */
list_del(&tp->rcu_node_entry);
tp->rcu_blocked_node = rnp_root;
list_add(&tp->rcu_node_entry, lp_root);
- spin_unlock(&rnp_root->lock); /* irqs remain disabled */
+ raw_spin_unlock(&rnp_root->lock); /* irqs remain disabled */
}
}
return retval;
@@ -516,7 +569,7 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp)
unsigned long flags;
unsigned long mask;
- spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
for (;;) {
if (!sync_rcu_preempt_exp_done(rnp))
break;
@@ -525,12 +578,12 @@ static void rcu_report_exp_rnp(struct rcu_state *rsp, struct rcu_node *rnp)
break;
}
mask = rnp->grpmask;
- spin_unlock(&rnp->lock); /* irqs remain disabled */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
rnp = rnp->parent;
- spin_lock(&rnp->lock); /* irqs already disabled */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled */
rnp->expmask &= ~mask;
}
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
@@ -545,11 +598,11 @@ sync_rcu_preempt_exp_init(struct rcu_state *rsp, struct rcu_node *rnp)
{
int must_wait;
- spin_lock(&rnp->lock); /* irqs already disabled */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled */
list_splice_init(&rnp->blocked_tasks[0], &rnp->blocked_tasks[2]);
list_splice_init(&rnp->blocked_tasks[1], &rnp->blocked_tasks[3]);
must_wait = rcu_preempted_readers_exp(rnp);
- spin_unlock(&rnp->lock); /* irqs remain disabled */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled */
if (!must_wait)
rcu_report_exp_rnp(rsp, rnp);
}
@@ -594,13 +647,13 @@ void synchronize_rcu_expedited(void)
/* force all RCU readers onto blocked_tasks[]. */
synchronize_sched_expedited();
- spin_lock_irqsave(&rsp->onofflock, flags);
+ raw_spin_lock_irqsave(&rsp->onofflock, flags);
/* Initialize ->expmask for all non-leaf rcu_node structures. */
rcu_for_each_nonleaf_node_breadth_first(rsp, rnp) {
- spin_lock(&rnp->lock); /* irqs already disabled. */
+ raw_spin_lock(&rnp->lock); /* irqs already disabled. */
rnp->expmask = rnp->qsmaskinit;
- spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
}
/* Snapshot current state of ->blocked_tasks[] lists. */
@@ -609,7 +662,7 @@ void synchronize_rcu_expedited(void)
if (NUM_RCU_NODES > 1)
sync_rcu_preempt_exp_init(rsp, rcu_get_root(rsp));
- spin_unlock_irqrestore(&rsp->onofflock, flags);
+ raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
/* Wait for snapshotted ->blocked_tasks[] lists to drain. */
rnp = rcu_get_root(rsp);
@@ -713,6 +766,16 @@ long rcu_batches_completed(void)
EXPORT_SYMBOL_GPL(rcu_batches_completed);
/*
+ * Force a quiescent state for RCU, which, because there is no preemptible
+ * RCU, becomes the same as rcu-sched.
+ */
+void rcu_force_quiescent_state(void)
+{
+ rcu_sched_force_quiescent_state();
+}
+EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
+
+/*
* Because preemptable RCU does not exist, we never have to check for
* CPUs being in quiescent states.
*/
@@ -734,7 +797,7 @@ static int rcu_preempted_readers(struct rcu_node *rnp)
/* Because preemptible RCU does not exist, no quieting of tasks. */
static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
{
- spin_unlock_irqrestore(&rnp->lock, flags);
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
@@ -745,6 +808,14 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags)
* Because preemptable RCU does not exist, we never have to check for
* tasks blocked within RCU read-side critical sections.
*/
+static void rcu_print_detail_task_stall(struct rcu_state *rsp)
+{
+}
+
+/*
+ * Because preemptable RCU does not exist, we never have to check for
+ * tasks blocked within RCU read-side critical sections.
+ */
static void rcu_print_task_stall(struct rcu_node *rnp)
{
}
@@ -884,3 +955,113 @@ static void __init __rcu_init_preempt(void)
}
#endif /* #else #ifdef CONFIG_TREE_PREEMPT_RCU */
+
+#if !defined(CONFIG_RCU_FAST_NO_HZ)
+
+/*
+ * Check to see if any future RCU-related work will need to be done
+ * by the current CPU, even if none need be done immediately, returning
+ * 1 if so. This function is part of the RCU implementation; it is -not-
+ * an exported member of the RCU API.
+ *
+ * Because we have preemptible RCU, just check whether this CPU needs
+ * any flavor of RCU. Do not chew up lots of CPU cycles with preemption
+ * disabled in a most-likely vain attempt to cause RCU not to need this CPU.
+ */
+int rcu_needs_cpu(int cpu)
+{
+ return rcu_needs_cpu_quick_check(cpu);
+}
+
+/*
+ * Check to see if we need to continue a callback-flush operations to
+ * allow the last CPU to enter dyntick-idle mode. But fast dyntick-idle
+ * entry is not configured, so we never do need to.
+ */
+static void rcu_needs_cpu_flush(void)
+{
+}
+
+#else /* #if !defined(CONFIG_RCU_FAST_NO_HZ) */
+
+#define RCU_NEEDS_CPU_FLUSHES 5
+static DEFINE_PER_CPU(int, rcu_dyntick_drain);
+static DEFINE_PER_CPU(unsigned long, rcu_dyntick_holdoff);
+
+/*
+ * Check to see if any future RCU-related work will need to be done
+ * by the current CPU, even if none need be done immediately, returning
+ * 1 if so. This function is part of the RCU implementation; it is -not-
+ * an exported member of the RCU API.
+ *
+ * Because we are not supporting preemptible RCU, attempt to accelerate
+ * any current grace periods so that RCU no longer needs this CPU, but
+ * only if all other CPUs are already in dynticks-idle mode. This will
+ * allow the CPU cores to be powered down immediately, as opposed to after
+ * waiting many milliseconds for grace periods to elapse.
+ *
+ * Because it is not legal to invoke rcu_process_callbacks() with irqs
+ * disabled, we do one pass of force_quiescent_state(), then do a
+ * raise_softirq() to cause rcu_process_callbacks() to be invoked later.
+ * The per-cpu rcu_dyntick_drain variable controls the sequencing.
+ */
+int rcu_needs_cpu(int cpu)
+{
+ int c = 0;
+ int thatcpu;
+
+ /* Don't bother unless we are the last non-dyntick-idle CPU. */
+ for_each_cpu_not(thatcpu, nohz_cpu_mask)
+ if (thatcpu != cpu) {
+ per_cpu(rcu_dyntick_drain, cpu) = 0;
+ per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
+ return rcu_needs_cpu_quick_check(cpu);
+ }
+
+ /* Check and update the rcu_dyntick_drain sequencing. */
+ if (per_cpu(rcu_dyntick_drain, cpu) <= 0) {
+ /* First time through, initialize the counter. */
+ per_cpu(rcu_dyntick_drain, cpu) = RCU_NEEDS_CPU_FLUSHES;
+ } else if (--per_cpu(rcu_dyntick_drain, cpu) <= 0) {
+ /* We have hit the limit, so time to give up. */
+ per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
+ return rcu_needs_cpu_quick_check(cpu);
+ }
+
+ /* Do one step pushing remaining RCU callbacks through. */
+ if (per_cpu(rcu_sched_data, cpu).nxtlist) {
+ rcu_sched_qs(cpu);
+ force_quiescent_state(&rcu_sched_state, 0);
+ c = c || per_cpu(rcu_sched_data, cpu).nxtlist;
+ }
+ if (per_cpu(rcu_bh_data, cpu).nxtlist) {
+ rcu_bh_qs(cpu);
+ force_quiescent_state(&rcu_bh_state, 0);
+ c = c || per_cpu(rcu_bh_data, cpu).nxtlist;
+ }
+
+ /* If RCU callbacks are still pending, RCU still needs this CPU. */
+ if (c) {
+ raise_softirq(RCU_SOFTIRQ);
+ per_cpu(rcu_dyntick_holdoff, cpu) = jiffies;
+ }
+ return c;
+}
+
+/*
+ * Check to see if we need to continue a callback-flush operations to
+ * allow the last CPU to enter dyntick-idle mode.
+ */
+static void rcu_needs_cpu_flush(void)
+{
+ int cpu = smp_processor_id();
+ unsigned long flags;
+
+ if (per_cpu(rcu_dyntick_drain, cpu) <= 0)
+ return;
+ local_irq_save(flags);
+ (void)rcu_needs_cpu(cpu);
+ local_irq_restore(flags);
+}
+
+#endif /* #else #if !defined(CONFIG_RCU_FAST_NO_HZ) */
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 9d2c88423b31..d45db2e35d27 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -50,7 +50,7 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
{
if (!rdp->beenonline)
return;
- seq_printf(m, "%3d%cc=%ld g=%ld pq=%d pqc=%ld qp=%d",
+ seq_printf(m, "%3d%cc=%lu g=%lu pq=%d pqc=%lu qp=%d",
rdp->cpu,
cpu_is_offline(rdp->cpu) ? '!' : ' ',
rdp->completed, rdp->gpnum,
@@ -105,7 +105,7 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
{
if (!rdp->beenonline)
return;
- seq_printf(m, "%d,%s,%ld,%ld,%d,%ld,%d",
+ seq_printf(m, "%d,%s,%lu,%lu,%d,%lu,%d",
rdp->cpu,
cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
rdp->completed, rdp->gpnum,
@@ -155,13 +155,13 @@ static const struct file_operations rcudata_csv_fops = {
static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
{
- long gpnum;
+ unsigned long gpnum;
int level = 0;
int phase;
struct rcu_node *rnp;
gpnum = rsp->gpnum;
- seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x "
+ seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
"nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld\n",
rsp->completed, gpnum, rsp->signaled,
(long)(rsp->jiffies_force_qs - jiffies),
@@ -215,12 +215,12 @@ static const struct file_operations rcuhier_fops = {
static int show_rcugp(struct seq_file *m, void *unused)
{
#ifdef CONFIG_TREE_PREEMPT_RCU
- seq_printf(m, "rcu_preempt: completed=%ld gpnum=%ld\n",
+ seq_printf(m, "rcu_preempt: completed=%ld gpnum=%lu\n",
rcu_preempt_state.completed, rcu_preempt_state.gpnum);
#endif /* #ifdef CONFIG_TREE_PREEMPT_RCU */
- seq_printf(m, "rcu_sched: completed=%ld gpnum=%ld\n",
+ seq_printf(m, "rcu_sched: completed=%ld gpnum=%lu\n",
rcu_sched_state.completed, rcu_sched_state.gpnum);
- seq_printf(m, "rcu_bh: completed=%ld gpnum=%ld\n",
+ seq_printf(m, "rcu_bh: completed=%ld gpnum=%lu\n",
rcu_bh_state.completed, rcu_bh_state.gpnum);
return 0;
}
diff --git a/kernel/resource.c b/kernel/resource.c
index af96c1e4b54b..24e9e60c1459 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -188,6 +188,36 @@ static int __release_resource(struct resource *old)
return -EINVAL;
}
+static void __release_child_resources(struct resource *r)
+{
+ struct resource *tmp, *p;
+ resource_size_t size;
+
+ p = r->child;
+ r->child = NULL;
+ while (p) {
+ tmp = p;
+ p = p->sibling;
+
+ tmp->parent = NULL;
+ tmp->sibling = NULL;
+ __release_child_resources(tmp);
+
+ printk(KERN_DEBUG "release child resource %pR\n", tmp);
+ /* need to restore size, and keep flags */
+ size = resource_size(tmp);
+ tmp->start = 0;
+ tmp->end = size - 1;
+ }
+}
+
+void release_child_resources(struct resource *r)
+{
+ write_lock(&resource_lock);
+ __release_child_resources(r);
+ write_unlock(&resource_lock);
+}
+
/**
* request_resource - request and reserve an I/O or memory resource
* @root: root resource descriptor
@@ -303,8 +333,10 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
static int find_resource(struct resource *root, struct resource *new,
resource_size_t size, resource_size_t min,
resource_size_t max, resource_size_t align,
- void (*alignf)(void *, struct resource *,
- resource_size_t, resource_size_t),
+ resource_size_t (*alignf)(void *,
+ const struct resource *,
+ resource_size_t,
+ resource_size_t),
void *alignf_data)
{
struct resource *this = root->child;
@@ -330,7 +362,7 @@ static int find_resource(struct resource *root, struct resource *new,
tmp.end = max;
tmp.start = ALIGN(tmp.start, align);
if (alignf)
- alignf(alignf_data, &tmp, size, align);
+ tmp.start = alignf(alignf_data, &tmp, size, align);
if (tmp.start < tmp.end && tmp.end - tmp.start >= size - 1) {
new->start = tmp.start;
new->end = tmp.start + size - 1;
@@ -358,8 +390,10 @@ static int find_resource(struct resource *root, struct resource *new,
int allocate_resource(struct resource *root, struct resource *new,
resource_size_t size, resource_size_t min,
resource_size_t max, resource_size_t align,
- void (*alignf)(void *, struct resource *,
- resource_size_t, resource_size_t),
+ resource_size_t (*alignf)(void *,
+ const struct resource *,
+ resource_size_t,
+ resource_size_t),
void *alignf_data)
{
int err;
diff --git a/kernel/sched.c b/kernel/sched.c
index 3a8fb30a91b1..3218f5213717 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -645,6 +645,11 @@ static inline int cpu_of(struct rq *rq)
#endif
}
+#define rcu_dereference_check_sched_domain(p) \
+ rcu_dereference_check((p), \
+ rcu_read_lock_sched_held() || \
+ lockdep_is_held(&sched_domains_mutex))
+
/*
* The domain tree (rq->sd) is protected by RCU's quiescent state transition.
* See detach_destroy_domains: synchronize_sched for details.
@@ -653,7 +658,7 @@ static inline int cpu_of(struct rq *rq)
* preempt-disabled sections.
*/
#define for_each_domain(cpu, __sd) \
- for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
+ for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent)
#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
#define this_rq() (&__get_cpu_var(runqueues))
@@ -1531,7 +1536,7 @@ static unsigned long target_load(int cpu, int type)
static struct sched_group *group_of(int cpu)
{
- struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd);
+ struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd);
if (!sd)
return NULL;
@@ -4888,7 +4893,7 @@ static void run_rebalance_domains(struct softirq_action *h)
static inline int on_null_domain(int cpu)
{
- return !rcu_dereference(cpu_rq(cpu)->sd);
+ return !rcu_dereference_sched(cpu_rq(cpu)->sd);
}
/*
diff --git a/kernel/smp.c b/kernel/smp.c
index f10408422444..9867b6bfefce 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -12,8 +12,6 @@
#include <linux/smp.h>
#include <linux/cpu.h>
-static DEFINE_PER_CPU(struct call_single_queue, call_single_queue);
-
static struct {
struct list_head queue;
raw_spinlock_t lock;
@@ -33,12 +31,14 @@ struct call_function_data {
cpumask_var_t cpumask;
};
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_function_data, cfd_data);
+
struct call_single_queue {
struct list_head list;
raw_spinlock_t lock;
};
-static DEFINE_PER_CPU(struct call_function_data, cfd_data);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_queue, call_single_queue);
static int
hotplug_cfd(struct notifier_block *nfb, unsigned long action, void *hcpu)
@@ -256,7 +256,7 @@ void generic_smp_call_function_single_interrupt(void)
}
}
-static DEFINE_PER_CPU(struct call_single_data, csd_data);
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct call_single_data, csd_data);
/*
* smp_call_function_single - Run a function on a specific CPU
diff --git a/kernel/srcu.c b/kernel/srcu.c
index 818d7d9aa03c..bde4295774c8 100644
--- a/kernel/srcu.c
+++ b/kernel/srcu.c
@@ -34,6 +34,30 @@
#include <linux/smp.h>
#include <linux/srcu.h>
+static int init_srcu_struct_fields(struct srcu_struct *sp)
+{
+ sp->completed = 0;
+ mutex_init(&sp->mutex);
+ sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
+ return sp->per_cpu_ref ? 0 : -ENOMEM;
+}
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+
+int __init_srcu_struct(struct srcu_struct *sp, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /* Don't re-initialize a lock while it is held. */
+ debug_check_no_locks_freed((void *)sp, sizeof(*sp));
+ lockdep_init_map(&sp->dep_map, name, key, 0);
+#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+ return init_srcu_struct_fields(sp);
+}
+EXPORT_SYMBOL_GPL(__init_srcu_struct);
+
+#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
/**
* init_srcu_struct - initialize a sleep-RCU structure
* @sp: structure to initialize.
@@ -44,13 +68,12 @@
*/
int init_srcu_struct(struct srcu_struct *sp)
{
- sp->completed = 0;
- mutex_init(&sp->mutex);
- sp->per_cpu_ref = alloc_percpu(struct srcu_struct_array);
- return (sp->per_cpu_ref ? 0 : -ENOMEM);
+ return init_srcu_struct_fields(sp);
}
EXPORT_SYMBOL_GPL(init_srcu_struct);
+#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+
/*
* srcu_readers_active_idx -- returns approximate number of readers
* active on the specified rank of per-CPU counters.
@@ -100,15 +123,12 @@ void cleanup_srcu_struct(struct srcu_struct *sp)
}
EXPORT_SYMBOL_GPL(cleanup_srcu_struct);
-/**
- * srcu_read_lock - register a new reader for an SRCU-protected structure.
- * @sp: srcu_struct in which to register the new reader.
- *
+/*
* Counts the new reader in the appropriate per-CPU element of the
* srcu_struct. Must be called from process context.
* Returns an index that must be passed to the matching srcu_read_unlock().
*/
-int srcu_read_lock(struct srcu_struct *sp)
+int __srcu_read_lock(struct srcu_struct *sp)
{
int idx;
@@ -120,31 +140,27 @@ int srcu_read_lock(struct srcu_struct *sp)
preempt_enable();
return idx;
}
-EXPORT_SYMBOL_GPL(srcu_read_lock);
+EXPORT_SYMBOL_GPL(__srcu_read_lock);
-/**
- * srcu_read_unlock - unregister a old reader from an SRCU-protected structure.
- * @sp: srcu_struct in which to unregister the old reader.
- * @idx: return value from corresponding srcu_read_lock().
- *
+/*
* Removes the count for the old reader from the appropriate per-CPU
* element of the srcu_struct. Note that this may well be a different
* CPU than that which was incremented by the corresponding srcu_read_lock().
* Must be called from process context.
*/
-void srcu_read_unlock(struct srcu_struct *sp, int idx)
+void __srcu_read_unlock(struct srcu_struct *sp, int idx)
{
preempt_disable();
srcu_barrier(); /* ensure compiler won't misorder critical section. */
per_cpu_ptr(sp->per_cpu_ref, smp_processor_id())->c[idx]--;
preempt_enable();
}
-EXPORT_SYMBOL_GPL(srcu_read_unlock);
+EXPORT_SYMBOL_GPL(__srcu_read_unlock);
/*
* Helper function for synchronize_srcu() and synchronize_srcu_expedited().
*/
-void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
+static void __synchronize_srcu(struct srcu_struct *sp, void (*sync_func)(void))
{
int idx;
generated by cgit v1.2.3 (git 2.0.4) at 2024-09-24 18:30:01 +0000