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authorIngo Molnar <mingo@elte.hu>2011-07-01 10:34:09 +0200
committerIngo Molnar <mingo@elte.hu>2011-07-01 10:34:24 +0200
commit36b2e922b5acd291051fab25bc7535274ce49532 (patch)
treeef4cdd6894075bb419cc31625b037f2b9212962f /kernel
parente197f094b7da7d94812492cfcd706d143f1020e5 (diff)
parentb0af8dfdd67699e25083478c63eedef2e72ebd85 (diff)
downloadlinux-stable-36b2e922b5acd291051fab25bc7535274ce49532.tar.gz
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Merge commit 'v3.0-rc5' into sched/core
Merge reason: Move to a (much) newer base. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cred.c2
-rw-r--r--kernel/events/core.c30
-rw-r--r--kernel/exit.c31
-rw-r--r--kernel/fork.c42
-rw-r--r--kernel/gcov/Kconfig3
-rw-r--r--kernel/irq/handle.c6
-rw-r--r--kernel/irq/irqdesc.c14
-rw-r--r--kernel/irq/manage.c27
-rw-r--r--kernel/irq/spurious.c31
-rw-r--r--kernel/jump_label.c18
-rw-r--r--kernel/kmod.c16
-rw-r--r--kernel/lockdep.c2
-rw-r--r--kernel/pm_qos_params.c70
-rw-r--r--kernel/power/hibernate.c220
-rw-r--r--kernel/power/user.c4
-rw-r--r--kernel/rcutree.c510
-rw-r--r--kernel/rcutree.h42
-rw-r--r--kernel/rcutree_plugin.h438
-rw-r--r--kernel/rcutree_trace.c44
-rw-r--r--kernel/sched.c21
-rw-r--r--kernel/sched_rt.c6
-rw-r--r--kernel/signal.c2
-rw-r--r--kernel/smp.c5
-rw-r--r--kernel/softirq.c2
-rw-r--r--kernel/sysctl.c6
-rw-r--r--kernel/taskstats.c15
-rw-r--r--kernel/time/alarmtimer.c158
-rw-r--r--kernel/time/clockevents.c5
-rw-r--r--kernel/time/clocksource.c24
-rw-r--r--kernel/timer.c15
-rw-r--r--kernel/trace/ftrace.c40
-rw-r--r--kernel/trace/ring_buffer.c10
-rw-r--r--kernel/trace/trace.h15
-rw-r--r--kernel/trace/trace_events.c7
-rw-r--r--kernel/trace/trace_kprobe.c8
-rw-r--r--kernel/trace/trace_output.c27
-rw-r--r--kernel/trace/trace_printk.c5
-rw-r--r--kernel/watchdog.c9
38 files changed, 1076 insertions, 854 deletions
diff --git a/kernel/cred.c b/kernel/cred.c
index e12c8af793f8..174fa84eca30 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -1,4 +1,4 @@
-/* Task credentials management - see Documentation/credentials.txt
+/* Task credentials management - see Documentation/security/credentials.txt
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index c09767f7db3e..9efe7108ccaf 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5028,6 +5028,14 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
else
perf_event_output(event, nmi, data, regs);
+ if (event->fasync && event->pending_kill) {
+ if (nmi) {
+ event->pending_wakeup = 1;
+ irq_work_queue(&event->pending);
+ } else
+ perf_event_wakeup(event);
+ }
+
return ret;
}
@@ -7394,26 +7402,12 @@ static int __perf_cgroup_move(void *info)
return 0;
}
-static void perf_cgroup_move(struct task_struct *task)
+static void
+perf_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *task)
{
task_function_call(task, __perf_cgroup_move, task);
}
-static void perf_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *task,
- bool threadgroup)
-{
- perf_cgroup_move(task);
- if (threadgroup) {
- struct task_struct *c;
- rcu_read_lock();
- list_for_each_entry_rcu(c, &task->thread_group, thread_group) {
- perf_cgroup_move(c);
- }
- rcu_read_unlock();
- }
-}
-
static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
struct cgroup *old_cgrp, struct task_struct *task)
{
@@ -7425,7 +7419,7 @@ static void perf_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp,
if (!(task->flags & PF_EXITING))
return;
- perf_cgroup_move(task);
+ perf_cgroup_attach_task(cgrp, task);
}
struct cgroup_subsys perf_subsys = {
@@ -7434,6 +7428,6 @@ struct cgroup_subsys perf_subsys = {
.create = perf_cgroup_create,
.destroy = perf_cgroup_destroy,
.exit = perf_cgroup_exit,
- .attach = perf_cgroup_attach,
+ .attach_task = perf_cgroup_attach_task,
};
#endif /* CONFIG_CGROUP_PERF */
diff --git a/kernel/exit.c b/kernel/exit.c
index 20a406471525..f2b321bae440 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -561,29 +561,28 @@ void exit_files(struct task_struct *tsk)
#ifdef CONFIG_MM_OWNER
/*
- * Task p is exiting and it owned mm, lets find a new owner for it
+ * A task is exiting. If it owned this mm, find a new owner for the mm.
*/
-static inline int
-mm_need_new_owner(struct mm_struct *mm, struct task_struct *p)
-{
- /*
- * If there are other users of the mm and the owner (us) is exiting
- * we need to find a new owner to take on the responsibility.
- */
- if (atomic_read(&mm->mm_users) <= 1)
- return 0;
- if (mm->owner != p)
- return 0;
- return 1;
-}
-
void mm_update_next_owner(struct mm_struct *mm)
{
struct task_struct *c, *g, *p = current;
retry:
- if (!mm_need_new_owner(mm, p))
+ /*
+ * If the exiting or execing task is not the owner, it's
+ * someone else's problem.
+ */
+ if (mm->owner != p)
return;
+ /*
+ * The current owner is exiting/execing and there are no other
+ * candidates. Do not leave the mm pointing to a possibly
+ * freed task structure.
+ */
+ if (atomic_read(&mm->mm_users) <= 1) {
+ mm->owner = NULL;
+ return;
+ }
read_lock(&tasklist_lock);
/*
diff --git a/kernel/fork.c b/kernel/fork.c
index ca406d916713..0276c30401a0 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -484,20 +484,6 @@ static void mm_init_aio(struct mm_struct *mm)
#endif
}
-int mm_init_cpumask(struct mm_struct *mm, struct mm_struct *oldmm)
-{
-#ifdef CONFIG_CPUMASK_OFFSTACK
- if (!alloc_cpumask_var(&mm->cpu_vm_mask_var, GFP_KERNEL))
- return -ENOMEM;
-
- if (oldmm)
- cpumask_copy(mm_cpumask(mm), mm_cpumask(oldmm));
- else
- memset(mm_cpumask(mm), 0, cpumask_size());
-#endif
- return 0;
-}
-
static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
{
atomic_set(&mm->mm_users, 1);
@@ -538,17 +524,8 @@ struct mm_struct * mm_alloc(void)
return NULL;
memset(mm, 0, sizeof(*mm));
- mm = mm_init(mm, current);
- if (!mm)
- return NULL;
-
- if (mm_init_cpumask(mm, NULL)) {
- mm_free_pgd(mm);
- free_mm(mm);
- return NULL;
- }
-
- return mm;
+ mm_init_cpumask(mm);
+ return mm_init(mm, current);
}
/*
@@ -559,7 +536,6 @@ struct mm_struct * mm_alloc(void)
void __mmdrop(struct mm_struct *mm)
{
BUG_ON(mm == &init_mm);
- free_cpumask_var(mm->cpu_vm_mask_var);
mm_free_pgd(mm);
destroy_context(mm);
mmu_notifier_mm_destroy(mm);
@@ -753,6 +729,7 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
goto fail_nomem;
memcpy(mm, oldmm, sizeof(*mm));
+ mm_init_cpumask(mm);
/* Initializing for Swap token stuff */
mm->token_priority = 0;
@@ -765,9 +742,6 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
if (!mm_init(mm, tsk))
goto fail_nomem;
- if (mm_init_cpumask(mm, oldmm))
- goto fail_nocpumask;
-
if (init_new_context(tsk, mm))
goto fail_nocontext;
@@ -794,9 +768,6 @@ fail_nomem:
return NULL;
fail_nocontext:
- free_cpumask_var(mm->cpu_vm_mask_var);
-
-fail_nocpumask:
/*
* If init_new_context() failed, we cannot use mmput() to free the mm
* because it calls destroy_context()
@@ -1591,6 +1562,13 @@ void __init proc_caches_init(void)
fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ /*
+ * FIXME! The "sizeof(struct mm_struct)" currently includes the
+ * whole struct cpumask for the OFFSTACK case. We could change
+ * this to *only* allocate as much of it as required by the
+ * maximum number of CPU's we can ever have. The cpumask_allocation
+ * is at the end of the structure, exactly for that reason.
+ */
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index b8cadf70b1fb..5bf924d80b5c 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -2,7 +2,8 @@ menu "GCOV-based kernel profiling"
config GCOV_KERNEL
bool "Enable gcov-based kernel profiling"
- depends on DEBUG_FS && CONSTRUCTORS
+ depends on DEBUG_FS
+ select CONSTRUCTORS
default n
---help---
This option enables gcov-based code profiling (e.g. for code coverage
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 90cb55f6d7eb..470d08c82bbe 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -133,12 +133,6 @@ handle_irq_event_percpu(struct irq_desc *desc, struct irqaction *action)
switch (res) {
case IRQ_WAKE_THREAD:
/*
- * Set result to handled so the spurious check
- * does not trigger.
- */
- res = IRQ_HANDLED;
-
- /*
* Catch drivers which return WAKE_THREAD but
* did not set up a thread function
*/
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index 886e80347b32..4c60a50e66b2 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -257,13 +257,11 @@ int __init early_irq_init(void)
count = ARRAY_SIZE(irq_desc);
for (i = 0; i < count; i++) {
- desc[i].irq_data.irq = i;
- desc[i].irq_data.chip = &no_irq_chip;
desc[i].kstat_irqs = alloc_percpu(unsigned int);
- irq_settings_clr_and_set(desc, ~0, _IRQ_DEFAULT_INIT_FLAGS);
- alloc_masks(desc + i, GFP_KERNEL, node);
- desc_smp_init(desc + i, node);
+ alloc_masks(&desc[i], GFP_KERNEL, node);
+ raw_spin_lock_init(&desc[i].lock);
lockdep_set_class(&desc[i].lock, &irq_desc_lock_class);
+ desc_set_defaults(i, &desc[i], node);
}
return arch_early_irq_init();
}
@@ -346,6 +344,12 @@ irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
if (!cnt)
return -EINVAL;
+ if (irq >= 0) {
+ if (from > irq)
+ return -EINVAL;
+ from = irq;
+ }
+
mutex_lock(&sparse_irq_lock);
start = bitmap_find_next_zero_area(allocated_irqs, IRQ_BITMAP_BITS,
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index f7ce0021e1c4..0a7840aeb0fb 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -491,6 +491,9 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on)
struct irq_desc *desc = irq_get_desc_buslock(irq, &flags);
int ret = 0;
+ if (!desc)
+ return -EINVAL;
+
/* wakeup-capable irqs can be shared between drivers that
* don't need to have the same sleep mode behaviors.
*/
@@ -723,13 +726,16 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { }
* context. So we need to disable bh here to avoid deadlocks and other
* side effects.
*/
-static void
+static irqreturn_t
irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
{
+ irqreturn_t ret;
+
local_bh_disable();
- action->thread_fn(action->irq, action->dev_id);
+ ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action, false);
local_bh_enable();
+ return ret;
}
/*
@@ -737,10 +743,14 @@ irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action)
* preemtible - many of them need to sleep and wait for slow busses to
* complete.
*/
-static void irq_thread_fn(struct irq_desc *desc, struct irqaction *action)
+static irqreturn_t irq_thread_fn(struct irq_desc *desc,
+ struct irqaction *action)
{
- action->thread_fn(action->irq, action->dev_id);
+ irqreturn_t ret;
+
+ ret = action->thread_fn(action->irq, action->dev_id);
irq_finalize_oneshot(desc, action, false);
+ return ret;
}
/*
@@ -753,7 +763,8 @@ static int irq_thread(void *data)
};
struct irqaction *action = data;
struct irq_desc *desc = irq_to_desc(action->irq);
- void (*handler_fn)(struct irq_desc *desc, struct irqaction *action);
+ irqreturn_t (*handler_fn)(struct irq_desc *desc,
+ struct irqaction *action);
int wake;
if (force_irqthreads & test_bit(IRQTF_FORCED_THREAD,
@@ -783,8 +794,12 @@ static int irq_thread(void *data)
desc->istate |= IRQS_PENDING;
raw_spin_unlock_irq(&desc->lock);
} else {
+ irqreturn_t action_ret;
+
raw_spin_unlock_irq(&desc->lock);
- handler_fn(desc, action);
+ action_ret = handler_fn(desc, action);
+ if (!noirqdebug)
+ note_interrupt(action->irq, desc, action_ret);
}
wake = atomic_dec_and_test(&desc->threads_active);
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index dfbd550401b2..aa57d5da18c1 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -167,6 +167,13 @@ out:
jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
}
+static inline int bad_action_ret(irqreturn_t action_ret)
+{
+ if (likely(action_ret <= (IRQ_HANDLED | IRQ_WAKE_THREAD)))
+ return 0;
+ return 1;
+}
+
/*
* If 99,900 of the previous 100,000 interrupts have not been handled
* then assume that the IRQ is stuck in some manner. Drop a diagnostic
@@ -182,7 +189,7 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc,
struct irqaction *action;
unsigned long flags;
- if (action_ret != IRQ_HANDLED && action_ret != IRQ_NONE) {
+ if (bad_action_ret(action_ret)) {
printk(KERN_ERR "irq event %d: bogus return value %x\n",
irq, action_ret);
} else {
@@ -201,10 +208,11 @@ __report_bad_irq(unsigned int irq, struct irq_desc *desc,
raw_spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
while (action) {
- printk(KERN_ERR "[<%p>]", action->handler);
- print_symbol(" (%s)",
- (unsigned long)action->handler);
- printk("\n");
+ printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler);
+ if (action->thread_fn)
+ printk(KERN_CONT " threaded [<%p>] %pf",
+ action->thread_fn, action->thread_fn);
+ printk(KERN_CONT "\n");
action = action->next;
}
raw_spin_unlock_irqrestore(&desc->lock, flags);
@@ -262,7 +270,16 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
if (desc->istate & IRQS_POLL_INPROGRESS)
return;
- if (unlikely(action_ret != IRQ_HANDLED)) {
+ /* we get here again via the threaded handler */
+ if (action_ret == IRQ_WAKE_THREAD)
+ return;
+
+ if (bad_action_ret(action_ret)) {
+ report_bad_irq(irq, desc, action_ret);
+ return;
+ }
+
+ if (unlikely(action_ret == IRQ_NONE)) {
/*
* If we are seeing only the odd spurious IRQ caused by
* bus asynchronicity then don't eventually trigger an error,
@@ -274,8 +291,6 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
else
desc->irqs_unhandled++;
desc->last_unhandled = jiffies;
- if (unlikely(action_ret != IRQ_NONE))
- report_bad_irq(irq, desc, action_ret);
}
if (unlikely(try_misrouted_irq(irq, desc, action_ret))) {
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index 74d1c099fbd1..fa27e750dbc0 100644
--- a/kernel/jump_label.c
+++ b/kernel/jump_label.c
@@ -105,9 +105,12 @@ static int __jump_label_text_reserved(struct jump_entry *iter_start,
}
static void __jump_label_update(struct jump_label_key *key,
- struct jump_entry *entry, int enable)
+ struct jump_entry *entry,
+ struct jump_entry *stop, int enable)
{
- for (; entry->key == (jump_label_t)(unsigned long)key; entry++) {
+ for (; (entry < stop) &&
+ (entry->key == (jump_label_t)(unsigned long)key);
+ entry++) {
/*
* entry->code set to 0 invalidates module init text sections
* kernel_text_address() verifies we are not in core kernel
@@ -181,7 +184,11 @@ static void __jump_label_mod_update(struct jump_label_key *key, int enable)
struct jump_label_mod *mod = key->next;
while (mod) {
- __jump_label_update(key, mod->entries, enable);
+ struct module *m = mod->mod;
+
+ __jump_label_update(key, mod->entries,
+ m->jump_entries + m->num_jump_entries,
+ enable);
mod = mod->next;
}
}
@@ -245,7 +252,8 @@ static int jump_label_add_module(struct module *mod)
key->next = jlm;
if (jump_label_enabled(key))
- __jump_label_update(key, iter, JUMP_LABEL_ENABLE);
+ __jump_label_update(key, iter, iter_stop,
+ JUMP_LABEL_ENABLE);
}
return 0;
@@ -371,7 +379,7 @@ static void jump_label_update(struct jump_label_key *key, int enable)
/* if there are no users, entry can be NULL */
if (entry)
- __jump_label_update(key, entry, enable);
+ __jump_label_update(key, entry, __stop___jump_table, enable);
#ifdef CONFIG_MODULES
__jump_label_mod_update(key, enable);
diff --git a/kernel/kmod.c b/kernel/kmod.c
index ad6a81c58b44..47613dfb7b28 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -156,12 +156,6 @@ static int ____call_usermodehelper(void *data)
*/
set_user_nice(current, 0);
- if (sub_info->init) {
- retval = sub_info->init(sub_info);
- if (retval)
- goto fail;
- }
-
retval = -ENOMEM;
new = prepare_kernel_cred(current);
if (!new)
@@ -173,6 +167,14 @@ static int ____call_usermodehelper(void *data)
new->cap_inheritable);
spin_unlock(&umh_sysctl_lock);
+ if (sub_info->init) {
+ retval = sub_info->init(sub_info, new);
+ if (retval) {
+ abort_creds(new);
+ goto fail;
+ }
+ }
+
commit_creds(new);
retval = kernel_execve(sub_info->path,
@@ -388,7 +390,7 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
* context in which call_usermodehelper_exec is called.
*/
void call_usermodehelper_setfns(struct subprocess_info *info,
- int (*init)(struct subprocess_info *info),
+ int (*init)(struct subprocess_info *info, struct cred *new),
void (*cleanup)(struct subprocess_info *info),
void *data)
{
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 63437d065ac8..298c9276dfdb 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -3426,7 +3426,7 @@ int lock_is_held(struct lockdep_map *lock)
int ret = 0;
if (unlikely(current->lockdep_recursion))
- return ret;
+ return 1; /* avoid false negative lockdep_assert_held() */
raw_local_irq_save(flags);
check_flags(flags);
diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
index beb184689af9..6824ca7d4d0c 100644
--- a/kernel/pm_qos_params.c
+++ b/kernel/pm_qos_params.c
@@ -40,6 +40,7 @@
#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/init.h>
+#include <linux/kernel.h>
#include <linux/uaccess.h>
@@ -53,11 +54,17 @@ enum pm_qos_type {
PM_QOS_MIN /* return the smallest value */
};
+/*
+ * Note: The lockless read path depends on the CPU accessing
+ * target_value atomically. Atomic access is only guaranteed on all CPU
+ * types linux supports for 32 bit quantites
+ */
struct pm_qos_object {
struct plist_head requests;
struct blocking_notifier_head *notifiers;
struct miscdevice pm_qos_power_miscdev;
char *name;
+ s32 target_value; /* Do not change to 64 bit */
s32 default_value;
enum pm_qos_type type;
};
@@ -70,7 +77,8 @@ static struct pm_qos_object cpu_dma_pm_qos = {
.requests = PLIST_HEAD_INIT(cpu_dma_pm_qos.requests, pm_qos_lock),
.notifiers = &cpu_dma_lat_notifier,
.name = "cpu_dma_latency",
- .default_value = 2000 * USEC_PER_SEC,
+ .target_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
+ .default_value = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE,
.type = PM_QOS_MIN,
};
@@ -79,7 +87,8 @@ static struct pm_qos_object network_lat_pm_qos = {
.requests = PLIST_HEAD_INIT(network_lat_pm_qos.requests, pm_qos_lock),
.notifiers = &network_lat_notifier,
.name = "network_latency",
- .default_value = 2000 * USEC_PER_SEC,
+ .target_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
+ .default_value = PM_QOS_NETWORK_LAT_DEFAULT_VALUE,
.type = PM_QOS_MIN
};
@@ -89,7 +98,8 @@ static struct pm_qos_object network_throughput_pm_qos = {
.requests = PLIST_HEAD_INIT(network_throughput_pm_qos.requests, pm_qos_lock),
.notifiers = &network_throughput_notifier,
.name = "network_throughput",
- .default_value = 0,
+ .target_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
+ .default_value = PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE,
.type = PM_QOS_MAX,
};
@@ -135,6 +145,16 @@ static inline int pm_qos_get_value(struct pm_qos_object *o)
}
}
+static inline s32 pm_qos_read_value(struct pm_qos_object *o)
+{
+ return o->target_value;
+}
+
+static inline void pm_qos_set_value(struct pm_qos_object *o, s32 value)
+{
+ o->target_value = value;
+}
+
static void update_target(struct pm_qos_object *o, struct plist_node *node,
int del, int value)
{
@@ -159,6 +179,7 @@ static void update_target(struct pm_qos_object *o, struct plist_node *node,
plist_add(node, &o->requests);
}
curr_value = pm_qos_get_value(o);
+ pm_qos_set_value(o, curr_value);
spin_unlock_irqrestore(&pm_qos_lock, flags);
if (prev_value != curr_value)
@@ -193,18 +214,11 @@ static int find_pm_qos_object_by_minor(int minor)
* pm_qos_request - returns current system wide qos expectation
* @pm_qos_class: identification of which qos value is requested
*
- * This function returns the current target value in an atomic manner.
+ * This function returns the current target value.
*/
int pm_qos_request(int pm_qos_class)
{
- unsigned long flags;
- int value;
-
- spin_lock_irqsave(&pm_qos_lock, flags);
- value = pm_qos_get_value(pm_qos_array[pm_qos_class]);
- spin_unlock_irqrestore(&pm_qos_lock, flags);
-
- return value;
+ return pm_qos_read_value(pm_qos_array[pm_qos_class]);
}
EXPORT_SYMBOL_GPL(pm_qos_request);
@@ -404,24 +418,36 @@ static ssize_t pm_qos_power_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos)
{
s32 value;
- int x;
- char ascii_value[11];
struct pm_qos_request_list *pm_qos_req;
if (count == sizeof(s32)) {
if (copy_from_user(&value, buf, sizeof(s32)))
return -EFAULT;
- } else if (count == 11) { /* len('0x12345678/0') */
- if (copy_from_user(ascii_value, buf, 11))
+ } else if (count <= 11) { /* ASCII perhaps? */
+ char ascii_value[11];
+ unsigned long int ulval;
+ int ret;
+
+ if (copy_from_user(ascii_value, buf, count))
return -EFAULT;
- if (strlen(ascii_value) != 10)
- return -EINVAL;
- x = sscanf(ascii_value, "%x", &value);
- if (x != 1)
+
+ if (count > 10) {
+ if (ascii_value[10] == '\n')
+ ascii_value[10] = '\0';
+ else
+ return -EINVAL;
+ } else {
+ ascii_value[count] = '\0';
+ }
+ ret = strict_strtoul(ascii_value, 16, &ulval);
+ if (ret) {
+ pr_debug("%s, 0x%lx, 0x%x\n", ascii_value, ulval, ret);
return -EINVAL;
- pr_debug("%s, %d, 0x%x\n", ascii_value, x, value);
- } else
+ }
+ value = (s32)lower_32_bits(ulval);
+ } else {
return -EINVAL;
+ }
pm_qos_req = filp->private_data;
pm_qos_update_request(pm_qos_req, value);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index f9bec56d8825..8f7b1db1ece1 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -25,7 +25,6 @@
#include <linux/gfp.h>
#include <linux/syscore_ops.h>
#include <scsi/scsi_scan.h>
-#include <asm/suspend.h>
#include "power.h"
@@ -55,10 +54,9 @@ static int hibernation_mode = HIBERNATION_SHUTDOWN;
static const struct platform_hibernation_ops *hibernation_ops;
/**
- * hibernation_set_ops - set the global hibernate operations
- * @ops: the hibernation operations to use in subsequent hibernation transitions
+ * hibernation_set_ops - Set the global hibernate operations.
+ * @ops: Hibernation operations to use in subsequent hibernation transitions.
*/
-
void hibernation_set_ops(const struct platform_hibernation_ops *ops)
{
if (ops && !(ops->begin && ops->end && ops->pre_snapshot
@@ -115,10 +113,9 @@ static int hibernation_test(int level) { return 0; }
#endif /* !CONFIG_PM_DEBUG */
/**
- * platform_begin - tell the platform driver that we're starting
- * hibernation
+ * platform_begin - Call platform to start hibernation.
+ * @platform_mode: Whether or not to use the platform driver.
*/
-
static int platform_begin(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
@@ -126,10 +123,9 @@ static int platform_begin(int platform_mode)
}
/**
- * platform_end - tell the platform driver that we've entered the
- * working state
+ * platform_end - Call platform to finish transition to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
*/
-
static void platform_end(int platform_mode)
{
if (platform_mode && hibernation_ops)
@@ -137,8 +133,11 @@ static void platform_end(int platform_mode)
}
/**
- * platform_pre_snapshot - prepare the machine for hibernation using the
- * platform driver if so configured and return an error code if it fails
+ * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to prepare the system for creating a hibernate image,
+ * if so configured, and return an error code if that fails.
*/
static int platform_pre_snapshot(int platform_mode)
@@ -148,10 +147,14 @@ static int platform_pre_snapshot(int platform_mode)
}
/**
- * platform_leave - prepare the machine for switching to the normal mode
- * of operation using the platform driver (called with interrupts disabled)
+ * platform_leave - Call platform to prepare a transition to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver prepare to prepare the machine for switching to the
+ * normal mode of operation.
+ *
+ * This routine is called on one CPU with interrupts disabled.
*/
-
static void platform_leave(int platform_mode)
{
if (platform_mode && hibernation_ops)
@@ -159,10 +162,14 @@ static void platform_leave(int platform_mode)
}
/**
- * platform_finish - switch the machine to the normal mode of operation
- * using the platform driver (must be called after platform_prepare())
+ * platform_finish - Call platform to switch the system to the working state.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to switch the machine to the normal mode of
+ * operation.
+ *
+ * This routine must be called after platform_prepare().
*/
-
static void platform_finish(int platform_mode)
{
if (platform_mode && hibernation_ops)
@@ -170,11 +177,15 @@ static void platform_finish(int platform_mode)
}
/**
- * platform_pre_restore - prepare the platform for the restoration from a
- * hibernation image. If the restore fails after this function has been
- * called, platform_restore_cleanup() must be called.
+ * platform_pre_restore - Prepare for hibernate image restoration.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to prepare the system for resume from a hibernation
+ * image.
+ *
+ * If the restore fails after this function has been called,
+ * platform_restore_cleanup() must be called.
*/
-
static int platform_pre_restore(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
@@ -182,12 +193,16 @@ static int platform_pre_restore(int platform_mode)
}
/**
- * platform_restore_cleanup - switch the platform to the normal mode of
- * operation after a failing restore. If platform_pre_restore() has been
- * called before the failing restore, this function must be called too,
- * regardless of the result of platform_pre_restore().
+ * platform_restore_cleanup - Switch to the working state after failing restore.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Use the platform driver to switch the system to the normal mode of operation
+ * after a failing restore.
+ *
+ * If platform_pre_restore() has been called before the failing restore, this
+ * function must be called too, regardless of the result of
+ * platform_pre_restore().
*/
-
static void platform_restore_cleanup(int platform_mode)
{
if (platform_mode && hibernation_ops)
@@ -195,10 +210,9 @@ static void platform_restore_cleanup(int platform_mode)
}
/**
- * platform_recover - recover the platform from a failure to suspend
- * devices.
+ * platform_recover - Recover from a failure to suspend devices.
+ * @platform_mode: Whether or not to use the platform driver.
*/
-
static void platform_recover(int platform_mode)
{
if (platform_mode && hibernation_ops && hibernation_ops->recover)
@@ -206,13 +220,12 @@ static void platform_recover(int platform_mode)
}
/**
- * swsusp_show_speed - print the time elapsed between two events.
- * @start: Starting event.
- * @stop: Final event.
- * @nr_pages - number of pages processed between @start and @stop
- * @msg - introductory message to print
+ * swsusp_show_speed - Print time elapsed between two events during hibernation.
+ * @start: Starting event.
+ * @stop: Final event.
+ * @nr_pages: Number of memory pages processed between @start and @stop.
+ * @msg: Additional diagnostic message to print.
*/
-
void swsusp_show_speed(struct timeval *start, struct timeval *stop,
unsigned nr_pages, char *msg)
{
@@ -235,25 +248,18 @@ void swsusp_show_speed(struct timeval *start, struct timeval *stop,
}
/**
- * create_image - freeze devices that need to be frozen with interrupts
- * off, create the hibernation image and thaw those devices. Control
- * reappears in this routine after a restore.
+ * create_image - Create a hibernation image.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
+ * and execute the drivers' .thaw_noirq() callbacks.
+ *
+ * Control reappears in this routine after the subsequent restore.
*/
-
static int create_image(int platform_mode)
{
int error;
- error = arch_prepare_suspend();
- if (error)
- return error;
-
- /* At this point, dpm_suspend_start() has been called, but *not*
- * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
- * Otherwise, drivers for some devices (e.g. interrupt controllers)
- * become desynchronized with the actual state of the hardware
- * at resume time, and evil weirdness ensues.
- */
error = dpm_suspend_noirq(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
@@ -297,9 +303,6 @@ static int create_image(int platform_mode)
Power_up:
syscore_resume();
- /* NOTE: dpm_resume_noirq() is just a resume() for devices
- * that suspended with irqs off ... no overall powerup.
- */
Enable_irqs:
local_irq_enable();
@@ -317,14 +320,11 @@ static int create_image(int platform_mode)
}
/**
- * hibernation_snapshot - quiesce devices and create the hibernation
- * snapshot image.
- * @platform_mode - if set, use the platform driver, if available, to
- * prepare the platform firmware for the power transition.
+ * hibernation_snapshot - Quiesce devices and create a hibernation image.
+ * @platform_mode: If set, use platform driver to prepare for the transition.
*
- * Must be called with pm_mutex held
+ * This routine must be called with pm_mutex held.
*/
-
int hibernation_snapshot(int platform_mode)
{
pm_message_t msg = PMSG_RECOVER;
@@ -384,13 +384,14 @@ int hibernation_snapshot(int platform_mode)
}
/**
- * resume_target_kernel - prepare devices that need to be suspended with
- * interrupts off, restore the contents of highmem that have not been
- * restored yet from the image and run the low level code that will restore
- * the remaining contents of memory and switch to the just restored target
- * kernel.
+ * resume_target_kernel - Restore system state from a hibernation image.
+ * @platform_mode: Whether or not to use the platform driver.
+ *
+ * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
+ * highmem that have not been restored yet from the image and run the low-level
+ * code that will restore the remaining contents of memory and switch to the
+ * just restored target kernel.
*/
-
static int resume_target_kernel(bool platform_mode)
{
int error;
@@ -416,24 +417,26 @@ static int resume_target_kernel(bool platform_mode)
if (error)
goto Enable_irqs;
- /* We'll ignore saved state, but this gets preempt count (etc) right */
save_processor_state();
error = restore_highmem();
if (!error) {
error = swsusp_arch_resume();
/*
* The code below is only ever reached in case of a failure.
- * Otherwise execution continues at place where
- * swsusp_arch_suspend() was called
+ * Otherwise, execution continues at the place where
+ * swsusp_arch_suspend() was called.
*/
BUG_ON(!error);
- /* This call to restore_highmem() undos the previous one */
+ /*
+ * This call to restore_highmem() reverts the changes made by
+ * the previous one.
+ */
restore_highmem();
}
/*
* The only reason why swsusp_arch_resume() can fail is memory being
* very tight, so we have to free it as soon as we can to avoid
- * subsequent failures
+ * subsequent failures.
*/
swsusp_free();
restore_processor_state();
@@ -456,14 +459,12 @@ static int resume_target_kernel(bool platform_mode)
}
/**
- * hibernation_restore - quiesce devices and restore the hibernation
- * snapshot image. If successful, control returns in hibernation_snaphot()
- * @platform_mode - if set, use the platform driver, if available, to
- * prepare the platform firmware for the transition.
+ * hibernation_restore - Quiesce devices and restore from a hibernation image.
+ * @platform_mode: If set, use platform driver to prepare for the transition.
*
- * Must be called with pm_mutex held
+ * This routine must be called with pm_mutex held. If it is successful, control
+ * reappears in the restored target kernel in hibernation_snaphot().
*/
-
int hibernation_restore(int platform_mode)
{
int error;
@@ -483,10 +484,8 @@ int hibernation_restore(int platform_mode)
}
/**
- * hibernation_platform_enter - enter the hibernation state using the
- * platform driver (if available)
+ * hibernation_platform_enter - Power off the system using the platform driver.
*/
-
int hibernation_platform_enter(void)
{
int error;
@@ -557,12 +556,12 @@ int hibernation_platform_enter(void)
}
/**
- * power_down - Shut the machine down for hibernation.
+ * power_down - Shut the machine down for hibernation.
*
- * Use the platform driver, if configured so; otherwise try
- * to power off or reboot.
+ * Use the platform driver, if configured, to put the system into the sleep
+ * state corresponding to hibernation, or try to power it off or reboot,
+ * depending on the value of hibernation_mode.
*/
-
static void power_down(void)
{
switch (hibernation_mode) {
@@ -599,9 +598,8 @@ static int prepare_processes(void)
}
/**
- * hibernate - The granpappy of the built-in hibernation management
+ * hibernate - Carry out system hibernation, including saving the image.
*/
-
int hibernate(void)
{
int error;
@@ -679,17 +677,20 @@ int hibernate(void)
/**
- * software_resume - Resume from a saved image.
+ * software_resume - Resume from a saved hibernation image.
*
- * Called as a late_initcall (so all devices are discovered and
- * initialized), we call swsusp to see if we have a saved image or not.
- * If so, we quiesce devices, the restore the saved image. We will
- * return above (in hibernate() ) if everything goes well.
- * Otherwise, we fail gracefully and return to the normally
- * scheduled program.
+ * This routine is called as a late initcall, when all devices have been
+ * discovered and initialized already.
*
+ * The image reading code is called to see if there is a hibernation image
+ * available for reading. If that is the case, devices are quiesced and the
+ * contents of memory is restored from the saved image.
+ *
+ * If this is successful, control reappears in the restored target kernel in
+ * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
+ * attempts to recover gracefully and make the kernel return to the normal mode
+ * of operation.
*/
-
static int software_resume(void)
{
int error;
@@ -819,21 +820,17 @@ static const char * const hibernation_modes[] = {
[HIBERNATION_TESTPROC] = "testproc",
};
-/**
- * disk - Control hibernation mode
- *
- * Suspend-to-disk can be handled in several ways. We have a few options
- * for putting the system to sleep - using the platform driver (e.g. ACPI
- * or other hibernation_ops), powering off the system or rebooting the
- * system (for testing) as well as the two test modes.
+/*
+ * /sys/power/disk - Control hibernation mode.
*
- * The system can support 'platform', and that is known a priori (and
- * encoded by the presence of hibernation_ops). However, the user may
- * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
- * test modes, 'test' or 'testproc'.
+ * Hibernation can be handled in several ways. There are a few different ways
+ * to put the system into the sleep state: using the platform driver (e.g. ACPI
+ * or other hibernation_ops), powering it off or rebooting it (for testing
+ * mostly), or using one of the two available test modes.
*
- * show() will display what the mode is currently set to.
- * store() will accept one of
+ * The sysfs file /sys/power/disk provides an interface for selecting the
+ * hibernation mode to use. Reading from this file causes the available modes
+ * to be printed. There are 5 modes that can be supported:
*
* 'platform'
* 'shutdown'
@@ -841,8 +838,14 @@ static const char * const hibernation_modes[] = {
* 'test'
* 'testproc'
*
- * It will only change to 'platform' if the system
- * supports it (as determined by having hibernation_ops).
+ * If a platform hibernation driver is in use, 'platform' will be supported
+ * and will be used by default. Otherwise, 'shutdown' will be used by default.
+ * The selected option (i.e. the one corresponding to the current value of
+ * hibernation_mode) is enclosed by a square bracket.
+ *
+ * To select a given hibernation mode it is necessary to write the mode's
+ * string representation (as returned by reading from /sys/power/disk) back
+ * into /sys/power/disk.
*/
static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
@@ -875,7 +878,6 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
return buf-start;
}
-
static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 7d02d33be699..42ddbc6f0de6 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -113,8 +113,10 @@ static int snapshot_open(struct inode *inode, struct file *filp)
if (error)
pm_notifier_call_chain(PM_POST_RESTORE);
}
- if (error)
+ if (error) {
+ free_basic_memory_bitmaps();
atomic_inc(&snapshot_device_available);
+ }
data->frozen = 0;
data->ready = 0;
data->platform_support = 0;
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f07d2f03181a..7e59ffb3d0ba 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -36,7 +36,7 @@
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/nmi.h>
-#include <asm/atomic.h>
+#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/completion.h>
@@ -87,6 +87,8 @@ static struct rcu_state *rcu_state;
int rcu_scheduler_active __read_mostly;
EXPORT_SYMBOL_GPL(rcu_scheduler_active);
+#ifdef CONFIG_RCU_BOOST
+
/*
* Control variables for per-CPU and per-rcu_node kthreads. These
* handle all flavors of RCU.
@@ -95,12 +97,14 @@ static DEFINE_PER_CPU(struct task_struct *, rcu_cpu_kthread_task);
DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
DEFINE_PER_CPU(int, rcu_cpu_kthread_cpu);
DEFINE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
-static DEFINE_PER_CPU(wait_queue_head_t, rcu_cpu_wq);
DEFINE_PER_CPU(char, rcu_cpu_has_work);
static char rcu_kthreads_spawnable;
+#endif /* #ifdef CONFIG_RCU_BOOST */
+
static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu);
-static void invoke_rcu_cpu_kthread(void);
+static void invoke_rcu_core(void);
+static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp);
#define RCU_KTHREAD_PRIO 1 /* RT priority for per-CPU kthreads. */
@@ -163,7 +167,7 @@ EXPORT_SYMBOL_GPL(rcu_note_context_switch);
#ifdef CONFIG_NO_HZ
DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
.dynticks_nesting = 1,
- .dynticks = 1,
+ .dynticks = ATOMIC_INIT(1),
};
#endif /* #ifdef CONFIG_NO_HZ */
@@ -322,13 +326,25 @@ void rcu_enter_nohz(void)
unsigned long flags;
struct rcu_dynticks *rdtp;
- smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
local_irq_save(flags);
rdtp = &__get_cpu_var(rcu_dynticks);
- rdtp->dynticks++;
- rdtp->dynticks_nesting--;
- WARN_ON_ONCE(rdtp->dynticks & 0x1);
+ if (--rdtp->dynticks_nesting) {
+ local_irq_restore(flags);
+ return;
+ }
+ /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
+ smp_mb__before_atomic_inc(); /* See above. */
+ atomic_inc(&rdtp->dynticks);
+ smp_mb__after_atomic_inc(); /* Force ordering with next sojourn. */
+ WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
local_irq_restore(flags);
+
+ /* If the interrupt queued a callback, get out of dyntick mode. */
+ if (in_irq() &&
+ (__get_cpu_var(rcu_sched_data).nxtlist ||
+ __get_cpu_var(rcu_bh_data).nxtlist ||
+ rcu_preempt_needs_cpu(smp_processor_id())))
+ set_need_resched();
}
/*
@@ -344,11 +360,16 @@ void rcu_exit_nohz(void)
local_irq_save(flags);
rdtp = &__get_cpu_var(rcu_dynticks);
- rdtp->dynticks++;
- rdtp->dynticks_nesting++;
- WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
+ if (rdtp->dynticks_nesting++) {
+ local_irq_restore(flags);
+ return;
+ }
+ smp_mb__before_atomic_inc(); /* Force ordering w/previous sojourn. */
+ atomic_inc(&rdtp->dynticks);
+ /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
+ smp_mb__after_atomic_inc(); /* See above. */
+ WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
local_irq_restore(flags);
- smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
}
/**
@@ -362,11 +383,15 @@ void rcu_nmi_enter(void)
{
struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
- if (rdtp->dynticks & 0x1)
+ if (rdtp->dynticks_nmi_nesting == 0 &&
+ (atomic_read(&rdtp->dynticks) & 0x1))
return;
- rdtp->dynticks_nmi++;
- WARN_ON_ONCE(!(rdtp->dynticks_nmi & 0x1));
- smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+ rdtp->dynticks_nmi_nesting++;
+ smp_mb__before_atomic_inc(); /* Force delay from prior write. */
+ atomic_inc(&rdtp->dynticks);
+ /* CPUs seeing atomic_inc() must see later RCU read-side crit sects */
+ smp_mb__after_atomic_inc(); /* See above. */
+ WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks) & 0x1));
}
/**
@@ -380,11 +405,14 @@ void rcu_nmi_exit(void)
{
struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
- if (rdtp->dynticks & 0x1)
+ if (rdtp->dynticks_nmi_nesting == 0 ||
+ --rdtp->dynticks_nmi_nesting != 0)
return;
- smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
- rdtp->dynticks_nmi++;
- WARN_ON_ONCE(rdtp->dynticks_nmi & 0x1);
+ /* CPUs seeing atomic_inc() must see prior RCU read-side crit sects */
+ smp_mb__before_atomic_inc(); /* See above. */
+ atomic_inc(&rdtp->dynticks);
+ smp_mb__after_atomic_inc(); /* Force delay to next write. */
+ WARN_ON_ONCE(atomic_read(&rdtp->dynticks) & 0x1);
}
/**
@@ -395,13 +423,7 @@ void rcu_nmi_exit(void)
*/
void rcu_irq_enter(void)
{
- struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
-
- if (rdtp->dynticks_nesting++)
- return;
- rdtp->dynticks++;
- WARN_ON_ONCE(!(rdtp->dynticks & 0x1));
- smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
+ rcu_exit_nohz();
}
/**
@@ -413,18 +435,7 @@ void rcu_irq_enter(void)
*/
void rcu_irq_exit(void)
{
- struct rcu_dynticks *rdtp = &__get_cpu_var(rcu_dynticks);
-
- if (--rdtp->dynticks_nesting)
- return;
- smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
- rdtp->dynticks++;
- WARN_ON_ONCE(rdtp->dynticks & 0x1);
-
- /* If the interrupt queued a callback, get out of dyntick mode. */
- if (__this_cpu_read(rcu_sched_data.nxtlist) ||
- __this_cpu_read(rcu_bh_data.nxtlist))
- set_need_resched();
+ rcu_enter_nohz();
}
#ifdef CONFIG_SMP
@@ -436,19 +447,8 @@ void rcu_irq_exit(void)
*/
static int dyntick_save_progress_counter(struct rcu_data *rdp)
{
- int ret;
- int snap;
- int snap_nmi;
-
- snap = rdp->dynticks->dynticks;
- snap_nmi = rdp->dynticks->dynticks_nmi;
- smp_mb(); /* Order sampling of snap with end of grace period. */
- rdp->dynticks_snap = snap;
- rdp->dynticks_nmi_snap = snap_nmi;
- ret = ((snap & 0x1) == 0) && ((snap_nmi & 0x1) == 0);
- if (ret)
- rdp->dynticks_fqs++;
- return ret;
+ rdp->dynticks_snap = atomic_add_return(0, &rdp->dynticks->dynticks);
+ return 0;
}
/*
@@ -459,16 +459,11 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp)
*/
static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
{
- long curr;
- long curr_nmi;
- long snap;
- long snap_nmi;
+ unsigned long curr;
+ unsigned long snap;
- curr = rdp->dynticks->dynticks;
- snap = rdp->dynticks_snap;
- curr_nmi = rdp->dynticks->dynticks_nmi;
- snap_nmi = rdp->dynticks_nmi_snap;
- smp_mb(); /* force ordering with cpu entering/leaving dynticks. */
+ curr = (unsigned long)atomic_add_return(0, &rdp->dynticks->dynticks);
+ snap = (unsigned long)rdp->dynticks_snap;
/*
* If the CPU passed through or entered a dynticks idle phase with
@@ -478,8 +473,7 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
* read-side critical section that started before the beginning
* of the current RCU grace period.
*/
- if ((curr != snap || (curr & 0x1) == 0) &&
- (curr_nmi != snap_nmi || (curr_nmi & 0x1) == 0)) {
+ if ((curr & 0x1) == 0 || ULONG_CMP_GE(curr, snap + 2)) {
rdp->dynticks_fqs++;
return 1;
}
@@ -908,6 +902,12 @@ static void rcu_report_qs_rsp(struct rcu_state *rsp, unsigned long flags)
unsigned long gp_duration;
WARN_ON_ONCE(!rcu_gp_in_progress(rsp));
+
+ /*
+ * Ensure that all grace-period and pre-grace-period activity
+ * is seen before the assignment to rsp->completed.
+ */
+ smp_mb(); /* See above block comment. */
gp_duration = jiffies - rsp->gp_start;
if (gp_duration > rsp->gp_max)
rsp->gp_max = gp_duration;
@@ -1093,14 +1093,8 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
int need_report = 0;
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_node *rnp;
- struct task_struct *t;
- /* Stop the CPU's kthread. */
- t = per_cpu(rcu_cpu_kthread_task, cpu);
- if (t != NULL) {
- per_cpu(rcu_cpu_kthread_task, cpu) = NULL;
- kthread_stop(t);
- }
+ rcu_stop_cpu_kthread(cpu);
/* Exclude any attempts to start a new grace period. */
raw_spin_lock_irqsave(&rsp->onofflock, flags);
@@ -1236,7 +1230,7 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
/* Re-raise the RCU softirq if there are callbacks remaining. */
if (cpu_has_callbacks_ready_to_invoke(rdp))
- invoke_rcu_cpu_kthread();
+ invoke_rcu_core();
}
/*
@@ -1282,7 +1276,7 @@ void rcu_check_callbacks(int cpu, int user)
}
rcu_preempt_check_callbacks(cpu);
if (rcu_pending(cpu))
- invoke_rcu_cpu_kthread();
+ invoke_rcu_core();
}
#ifdef CONFIG_SMP
@@ -1447,33 +1441,20 @@ __rcu_process_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
}
/* If there are callbacks ready, invoke them. */
- rcu_do_batch(rsp, rdp);
+ if (cpu_has_callbacks_ready_to_invoke(rdp))
+ invoke_rcu_callbacks(rsp, rdp);
}
/*
* Do softirq processing for the current CPU.
*/
-static void rcu_process_callbacks(void)
+static void rcu_process_callbacks(struct softirq_action *unused)
{
- /*
- * Memory references from any prior RCU read-side critical sections
- * executed by the interrupted code must be seen before any RCU
- * grace-period manipulations below.
- */
- smp_mb(); /* See above block comment. */
-
__rcu_process_callbacks(&rcu_sched_state,
&__get_cpu_var(rcu_sched_data));
__rcu_process_callbacks(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
rcu_preempt_process_callbacks();
- /*
- * Memory references from any later RCU read-side critical sections
- * executed by the interrupted code must be seen after any RCU
- * 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();
}
@@ -1484,341 +1465,20 @@ static void rcu_process_callbacks(void)
* the current CPU with interrupts disabled, the rcu_cpu_kthread_task
* cannot disappear out from under us.
*/
-static void invoke_rcu_cpu_kthread(void)
+static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp)
{
- unsigned long flags;
-
- local_irq_save(flags);
- __this_cpu_write(rcu_cpu_has_work, 1);
- if (__this_cpu_read(rcu_cpu_kthread_task) == NULL) {
- local_irq_restore(flags);
+ if (likely(!rsp->boost)) {
+ rcu_do_batch(rsp, rdp);
return;
}
- wake_up(&__get_cpu_var(rcu_cpu_wq));
- local_irq_restore(flags);
-}
-
-/*
- * Wake up the specified per-rcu_node-structure kthread.
- * Because the per-rcu_node kthreads are immortal, we don't need
- * to do anything to keep them alive.
- */
-static void invoke_rcu_node_kthread(struct rcu_node *rnp)
-{
- struct task_struct *t;
-
- t = rnp->node_kthread_task;
- if (t != NULL)
- wake_up_process(t);
+ invoke_rcu_callbacks_kthread();
}
-/*
- * Set the specified CPU's kthread to run RT or not, as specified by
- * the to_rt argument. The CPU-hotplug locks are held, so the task
- * is not going away.
- */
-static void rcu_cpu_kthread_setrt(int cpu, int to_rt)
+static void invoke_rcu_core(void)
{
- int policy;
- struct sched_param sp;
- struct task_struct *t;
-
- t = per_cpu(rcu_cpu_kthread_task, cpu);
- if (t == NULL)
- return;
- if (to_rt) {
- policy = SCHED_FIFO;
- sp.sched_priority = RCU_KTHREAD_PRIO;
- } else {
- policy = SCHED_NORMAL;
- sp.sched_priority = 0;
- }
- sched_setscheduler_nocheck(t, policy, &sp);
+ raise_softirq(RCU_SOFTIRQ);
}
-/*
- * Timer handler to initiate the waking up of per-CPU kthreads that
- * have yielded the CPU due to excess numbers of RCU callbacks.
- * We wake up the per-rcu_node kthread, which in turn will wake up
- * the booster kthread.
- */
-static void rcu_cpu_kthread_timer(unsigned long arg)
-{
- unsigned long flags;
- struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, arg);
- struct rcu_node *rnp = rdp->mynode;
-
- raw_spin_lock_irqsave(&rnp->lock, flags);
- rnp->wakemask |= rdp->grpmask;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
- invoke_rcu_node_kthread(rnp);
-}
-
-/*
- * Drop to non-real-time priority and yield, but only after posting a
- * timer that will cause us to regain our real-time priority if we
- * remain preempted. Either way, we restore our real-time priority
- * before returning.
- */
-static void rcu_yield(void (*f)(unsigned long), unsigned long arg)
-{
- struct sched_param sp;
- struct timer_list yield_timer;
-
- setup_timer_on_stack(&yield_timer, f, arg);
- mod_timer(&yield_timer, jiffies + 2);
- sp.sched_priority = 0;
- sched_setscheduler_nocheck(current, SCHED_NORMAL, &sp);
- set_user_nice(current, 19);
- schedule();
- sp.sched_priority = RCU_KTHREAD_PRIO;
- sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
- del_timer(&yield_timer);
-}
-
-/*
- * Handle cases where the rcu_cpu_kthread() ends up on the wrong CPU.
- * This can happen while the corresponding CPU is either coming online
- * or going offline. We cannot wait until the CPU is fully online
- * before starting the kthread, because the various notifier functions
- * can wait for RCU grace periods. So we park rcu_cpu_kthread() until
- * the corresponding CPU is online.
- *
- * Return 1 if the kthread needs to stop, 0 otherwise.
- *
- * Caller must disable bh. This function can momentarily enable it.
- */
-static int rcu_cpu_kthread_should_stop(int cpu)
-{
- while (cpu_is_offline(cpu) ||
- !cpumask_equal(&current->cpus_allowed, cpumask_of(cpu)) ||
- smp_processor_id() != cpu) {
- if (kthread_should_stop())
- return 1;
- per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
- per_cpu(rcu_cpu_kthread_cpu, cpu) = raw_smp_processor_id();
- local_bh_enable();
- schedule_timeout_uninterruptible(1);
- if (!cpumask_equal(&current->cpus_allowed, cpumask_of(cpu)))
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
- local_bh_disable();
- }
- per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
- return 0;
-}
-
-/*
- * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
- * earlier RCU softirq.
- */
-static int rcu_cpu_kthread(void *arg)
-{
- int cpu = (int)(long)arg;
- unsigned long flags;
- int spincnt = 0;
- unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu);
- wait_queue_head_t *wqp = &per_cpu(rcu_cpu_wq, cpu);
- char work;
- char *workp = &per_cpu(rcu_cpu_has_work, cpu);
-
- for (;;) {
- *statusp = RCU_KTHREAD_WAITING;
- wait_event_interruptible(*wqp,
- *workp != 0 || kthread_should_stop());
- local_bh_disable();
- if (rcu_cpu_kthread_should_stop(cpu)) {
- local_bh_enable();
- break;
- }
- *statusp = RCU_KTHREAD_RUNNING;
- per_cpu(rcu_cpu_kthread_loops, cpu)++;
- local_irq_save(flags);
- work = *workp;
- *workp = 0;
- local_irq_restore(flags);
- if (work)
- rcu_process_callbacks();
- local_bh_enable();
- if (*workp != 0)
- spincnt++;
- else
- spincnt = 0;
- if (spincnt > 10) {
- *statusp = RCU_KTHREAD_YIELDING;
- rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu);
- spincnt = 0;
- }
- }
- *statusp = RCU_KTHREAD_STOPPED;
- return 0;
-}
-
-/*
- * Spawn a per-CPU kthread, setting up affinity and priority.
- * Because the CPU hotplug lock is held, no other CPU will be attempting
- * to manipulate rcu_cpu_kthread_task. There might be another CPU
- * attempting to access it during boot, but the locking in kthread_bind()
- * will enforce sufficient ordering.
- */
-static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
-{
- struct sched_param sp;
- struct task_struct *t;
-
- if (!rcu_kthreads_spawnable ||
- per_cpu(rcu_cpu_kthread_task, cpu) != NULL)
- return 0;
- t = kthread_create(rcu_cpu_kthread, (void *)(long)cpu, "rcuc%d", cpu);
- if (IS_ERR(t))
- return PTR_ERR(t);
- kthread_bind(t, cpu);
- per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
- WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL);
- per_cpu(rcu_cpu_kthread_task, cpu) = t;
- wake_up_process(t);
- sp.sched_priority = RCU_KTHREAD_PRIO;
- sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
- return 0;
-}
-
-/*
- * Per-rcu_node kthread, which is in charge of waking up the per-CPU
- * kthreads when needed. We ignore requests to wake up kthreads
- * for offline CPUs, which is OK because force_quiescent_state()
- * takes care of this case.
- */
-static int rcu_node_kthread(void *arg)
-{
- int cpu;
- unsigned long flags;
- unsigned long mask;
- struct rcu_node *rnp = (struct rcu_node *)arg;
- struct sched_param sp;
- struct task_struct *t;
-
- for (;;) {
- rnp->node_kthread_status = RCU_KTHREAD_WAITING;
- wait_event_interruptible(rnp->node_wq, rnp->wakemask != 0);
- rnp->node_kthread_status = RCU_KTHREAD_RUNNING;
- raw_spin_lock_irqsave(&rnp->lock, flags);
- mask = rnp->wakemask;
- rnp->wakemask = 0;
- rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) {
- if ((mask & 0x1) == 0)
- continue;
- preempt_disable();
- t = per_cpu(rcu_cpu_kthread_task, cpu);
- if (!cpu_online(cpu) || t == NULL) {
- preempt_enable();
- continue;
- }
- per_cpu(rcu_cpu_has_work, cpu) = 1;
- sp.sched_priority = RCU_KTHREAD_PRIO;
- sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
- preempt_enable();
- }
- }
- /* NOTREACHED */
- rnp->node_kthread_status = RCU_KTHREAD_STOPPED;
- return 0;
-}
-
-/*
- * Set the per-rcu_node kthread's affinity to cover all CPUs that are
- * served by the rcu_node in question. The CPU hotplug lock is still
- * held, so the value of rnp->qsmaskinit will be stable.
- *
- * We don't include outgoingcpu in the affinity set, use -1 if there is
- * no outgoing CPU. If there are no CPUs left in the affinity set,
- * this function allows the kthread to execute on any CPU.
- */
-static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
-{
- cpumask_var_t cm;
- int cpu;
- unsigned long mask = rnp->qsmaskinit;
-
- if (rnp->node_kthread_task == NULL)
- return;
- if (!alloc_cpumask_var(&cm, GFP_KERNEL))
- return;
- cpumask_clear(cm);
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1)
- if ((mask & 0x1) && cpu != outgoingcpu)
- cpumask_set_cpu(cpu, cm);
- if (cpumask_weight(cm) == 0) {
- cpumask_setall(cm);
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++)
- cpumask_clear_cpu(cpu, cm);
- WARN_ON_ONCE(cpumask_weight(cm) == 0);
- }
- set_cpus_allowed_ptr(rnp->node_kthread_task, cm);
- rcu_boost_kthread_setaffinity(rnp, cm);
- free_cpumask_var(cm);
-}
-
-/*
- * Spawn a per-rcu_node kthread, setting priority and affinity.
- * Called during boot before online/offline can happen, or, if
- * during runtime, with the main CPU-hotplug locks held. So only
- * one of these can be executing at a time.
- */
-static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp,
- struct rcu_node *rnp)
-{
- unsigned long flags;
- int rnp_index = rnp - &rsp->node[0];
- struct sched_param sp;
- struct task_struct *t;
-
- if (!rcu_kthreads_spawnable ||
- rnp->qsmaskinit == 0)
- return 0;
- if (rnp->node_kthread_task == NULL) {
- t = kthread_create(rcu_node_kthread, (void *)rnp,
- "rcun%d", rnp_index);
- if (IS_ERR(t))
- return PTR_ERR(t);
- raw_spin_lock_irqsave(&rnp->lock, flags);
- rnp->node_kthread_task = t;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
- wake_up_process(t);
- sp.sched_priority = 99;
- sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
- }
- return rcu_spawn_one_boost_kthread(rsp, rnp, rnp_index);
-}
-
-/*
- * Spawn all kthreads -- called as soon as the scheduler is running.
- */
-static int __init rcu_spawn_kthreads(void)
-{
- int cpu;
- struct rcu_node *rnp;
-
- rcu_kthreads_spawnable = 1;
- for_each_possible_cpu(cpu) {
- init_waitqueue_head(&per_cpu(rcu_cpu_wq, cpu));
- per_cpu(rcu_cpu_has_work, cpu) = 0;
- if (cpu_online(cpu))
- (void)rcu_spawn_one_cpu_kthread(cpu);
- }
- rnp = rcu_get_root(rcu_state);
- init_waitqueue_head(&rnp->node_wq);
- rcu_init_boost_waitqueue(rnp);
- (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
- if (NUM_RCU_NODES > 1)
- rcu_for_each_leaf_node(rcu_state, rnp) {
- init_waitqueue_head(&rnp->node_wq);
- rcu_init_boost_waitqueue(rnp);
- (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
- }
- return 0;
-}
-early_initcall(rcu_spawn_kthreads);
-
static void
__call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu),
struct rcu_state *rsp)
@@ -2218,26 +1878,13 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp, int preemptible)
raw_spin_unlock_irqrestore(&rsp->onofflock, flags);
}
-static void __cpuinit rcu_online_cpu(int cpu)
+static void __cpuinit rcu_prepare_cpu(int cpu)
{
rcu_init_percpu_data(cpu, &rcu_sched_state, 0);
rcu_init_percpu_data(cpu, &rcu_bh_state, 0);
rcu_preempt_init_percpu_data(cpu);
}
-static void __cpuinit rcu_online_kthreads(int cpu)
-{
- struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu);
- struct rcu_node *rnp = rdp->mynode;
-
- /* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */
- if (rcu_kthreads_spawnable) {
- (void)rcu_spawn_one_cpu_kthread(cpu);
- if (rnp->node_kthread_task == NULL)
- (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
- }
-}
-
/*
* Handle CPU online/offline notification events.
*/
@@ -2251,8 +1898,8 @@ static int __cpuinit rcu_cpu_notify(struct notifier_block *self,
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- rcu_online_cpu(cpu);
- rcu_online_kthreads(cpu);
+ rcu_prepare_cpu(cpu);
+ rcu_prepare_kthreads(cpu);
break;
case CPU_ONLINE:
case CPU_DOWN_FAILED:
@@ -2402,6 +2049,7 @@ void __init rcu_init(void)
rcu_init_one(&rcu_sched_state, &rcu_sched_data);
rcu_init_one(&rcu_bh_state, &rcu_bh_data);
__rcu_init_preempt();
+ open_softirq(RCU_SOFTIRQ, rcu_process_callbacks);
/*
* We don't need protection against CPU-hotplug here because
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 257664815d5d..01b2ccda26fb 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -84,11 +84,9 @@
* Dynticks per-CPU state.
*/
struct rcu_dynticks {
- int dynticks_nesting; /* Track nesting level, sort of. */
- int dynticks; /* Even value for dynticks-idle, else odd. */
- int dynticks_nmi; /* Even value for either dynticks-idle or */
- /* not in nmi handler, else odd. So this */
- /* remains even for nmi from irq handler. */
+ int dynticks_nesting; /* Track irq/process nesting level. */
+ int dynticks_nmi_nesting; /* Track NMI nesting level. */
+ atomic_t dynticks; /* Even value for dynticks-idle, else odd. */
};
/* RCU's kthread states for tracing. */
@@ -121,7 +119,9 @@ struct rcu_node {
/* elements that need to drain to allow the */
/* current expedited grace period to */
/* complete (only for TREE_PREEMPT_RCU). */
- unsigned long wakemask; /* CPUs whose kthread needs to be awakened. */
+ atomic_t wakemask; /* CPUs whose kthread needs to be awakened. */
+ /* Since this has meaning only for leaf */
+ /* rcu_node structures, 32 bits suffices. */
unsigned long qsmaskinit;
/* Per-GP initial value for qsmask & expmask. */
unsigned long grpmask; /* Mask to apply to parent qsmask. */
@@ -159,9 +159,6 @@ struct rcu_node {
struct task_struct *boost_kthread_task;
/* kthread that takes care of priority */
/* boosting for this rcu_node structure. */
- wait_queue_head_t boost_wq;
- /* Wait queue on which to park the boost */
- /* kthread. */
unsigned int boost_kthread_status;
/* State of boost_kthread_task for tracing. */
unsigned long n_tasks_boosted;
@@ -188,9 +185,6 @@ struct rcu_node {
/* kthread that takes care of this rcu_node */
/* structure, for example, awakening the */
/* per-CPU kthreads as needed. */
- wait_queue_head_t node_wq;
- /* Wait queue on which to park the per-node */
- /* kthread. */
unsigned int node_kthread_status;
/* State of node_kthread_task for tracing. */
} ____cacheline_internodealigned_in_smp;
@@ -284,7 +278,6 @@ struct rcu_data {
/* 3) dynticks interface. */
struct rcu_dynticks *dynticks; /* Shared per-CPU dynticks state. */
int dynticks_snap; /* Per-GP tracking for dynticks. */
- int dynticks_nmi_snap; /* Per-GP tracking for dynticks_nmi. */
#endif /* #ifdef CONFIG_NO_HZ */
/* 4) reasons this CPU needed to be kicked by force_quiescent_state */
@@ -337,6 +330,16 @@ struct rcu_data {
/* scheduling clock irq */
/* before ratting on them. */
+#define rcu_wait(cond) \
+do { \
+ for (;;) { \
+ set_current_state(TASK_INTERRUPTIBLE); \
+ if (cond) \
+ break; \
+ schedule(); \
+ } \
+ __set_current_state(TASK_RUNNING); \
+} while (0)
/*
* RCU global state, including node hierarchy. This hierarchy is
@@ -366,6 +369,7 @@ struct rcu_state {
/* period because */
/* force_quiescent_state() */
/* was running. */
+ u8 boost; /* Subject to priority boost. */
unsigned long gpnum; /* Current gp number. */
unsigned long completed; /* # of last completed gp. */
@@ -423,6 +427,7 @@ static int rcu_preempt_blocked_readers_cgp(struct rcu_node *rnp);
#ifdef CONFIG_HOTPLUG_CPU
static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
unsigned long flags);
+static void rcu_stop_cpu_kthread(int cpu);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
static void rcu_print_detail_task_stall(struct rcu_state *rsp);
static void rcu_print_task_stall(struct rcu_node *rnp);
@@ -446,13 +451,20 @@ static void __cpuinit rcu_preempt_init_percpu_data(int cpu);
static void rcu_preempt_send_cbs_to_online(void);
static void __init __rcu_init_preempt(void);
static void rcu_needs_cpu_flush(void);
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp);
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
+static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
+static void invoke_rcu_callbacks_kthread(void);
+#ifdef CONFIG_RCU_BOOST
+static void rcu_preempt_do_callbacks(void);
static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp,
cpumask_var_t cm);
-static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
struct rcu_node *rnp,
int rnp_index);
+static void invoke_rcu_node_kthread(struct rcu_node *rnp);
+static void rcu_yield(void (*f)(unsigned long), unsigned long arg);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+static void rcu_cpu_kthread_setrt(int cpu, int to_rt);
+static void __cpuinit rcu_prepare_kthreads(int cpu);
#endif /* #ifndef RCU_TREE_NONCORE */
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 3f6559a5f5cd..14dc7dd00902 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -602,6 +602,15 @@ static void rcu_preempt_process_callbacks(void)
&__get_cpu_var(rcu_preempt_data));
}
+#ifdef CONFIG_RCU_BOOST
+
+static void rcu_preempt_do_callbacks(void)
+{
+ rcu_do_batch(&rcu_preempt_state, &__get_cpu_var(rcu_preempt_data));
+}
+
+#endif /* #ifdef CONFIG_RCU_BOOST */
+
/*
* Queue a preemptible-RCU callback for invocation after a grace period.
*/
@@ -1196,8 +1205,7 @@ static int rcu_boost_kthread(void *arg)
for (;;) {
rnp->boost_kthread_status = RCU_KTHREAD_WAITING;
- wait_event_interruptible(rnp->boost_wq, rnp->boost_tasks ||
- rnp->exp_tasks);
+ rcu_wait(rnp->boost_tasks || rnp->exp_tasks);
rnp->boost_kthread_status = RCU_KTHREAD_RUNNING;
more2boost = rcu_boost(rnp);
if (more2boost)
@@ -1250,6 +1258,23 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
}
/*
+ * Wake up the per-CPU kthread to invoke RCU callbacks.
+ */
+static void invoke_rcu_callbacks_kthread(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __this_cpu_write(rcu_cpu_has_work, 1);
+ if (__this_cpu_read(rcu_cpu_kthread_task) == NULL) {
+ local_irq_restore(flags);
+ return;
+ }
+ wake_up_process(__this_cpu_read(rcu_cpu_kthread_task));
+ local_irq_restore(flags);
+}
+
+/*
* Set the affinity of the boost kthread. The CPU-hotplug locks are
* held, so no one should be messing with the existence of the boost
* kthread.
@@ -1275,14 +1300,6 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp)
}
/*
- * Initialize the RCU-boost waitqueue.
- */
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp)
-{
- init_waitqueue_head(&rnp->boost_wq);
-}
-
-/*
* Create an RCU-boost kthread for the specified node if one does not
* already exist. We only create this kthread for preemptible RCU.
* Returns zero if all is well, a negated errno otherwise.
@@ -1297,6 +1314,7 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
if (&rcu_preempt_state != rsp)
return 0;
+ rsp->boost = 1;
if (rnp->boost_kthread_task != NULL)
return 0;
t = kthread_create(rcu_boost_kthread, (void *)rnp,
@@ -1306,12 +1324,376 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
raw_spin_lock_irqsave(&rnp->lock, flags);
rnp->boost_kthread_task = t;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
- wake_up_process(t);
sp.sched_priority = RCU_KTHREAD_PRIO;
sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+ wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
return 0;
}
+#ifdef CONFIG_HOTPLUG_CPU
+
+/*
+ * Stop the RCU's per-CPU kthread when its CPU goes offline,.
+ */
+static void rcu_stop_cpu_kthread(int cpu)
+{
+ struct task_struct *t;
+
+ /* Stop the CPU's kthread. */
+ t = per_cpu(rcu_cpu_kthread_task, cpu);
+ if (t != NULL) {
+ per_cpu(rcu_cpu_kthread_task, cpu) = NULL;
+ kthread_stop(t);
+ }
+}
+
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+static void rcu_kthread_do_work(void)
+{
+ rcu_do_batch(&rcu_sched_state, &__get_cpu_var(rcu_sched_data));
+ rcu_do_batch(&rcu_bh_state, &__get_cpu_var(rcu_bh_data));
+ rcu_preempt_do_callbacks();
+}
+
+/*
+ * Wake up the specified per-rcu_node-structure kthread.
+ * Because the per-rcu_node kthreads are immortal, we don't need
+ * to do anything to keep them alive.
+ */
+static void invoke_rcu_node_kthread(struct rcu_node *rnp)
+{
+ struct task_struct *t;
+
+ t = rnp->node_kthread_task;
+ if (t != NULL)
+ wake_up_process(t);
+}
+
+/*
+ * Set the specified CPU's kthread to run RT or not, as specified by
+ * the to_rt argument. The CPU-hotplug locks are held, so the task
+ * is not going away.
+ */
+static void rcu_cpu_kthread_setrt(int cpu, int to_rt)
+{
+ int policy;
+ struct sched_param sp;
+ struct task_struct *t;
+
+ t = per_cpu(rcu_cpu_kthread_task, cpu);
+ if (t == NULL)
+ return;
+ if (to_rt) {
+ policy = SCHED_FIFO;
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ } else {
+ policy = SCHED_NORMAL;
+ sp.sched_priority = 0;
+ }
+ sched_setscheduler_nocheck(t, policy, &sp);
+}
+
+/*
+ * Timer handler to initiate the waking up of per-CPU kthreads that
+ * have yielded the CPU due to excess numbers of RCU callbacks.
+ * We wake up the per-rcu_node kthread, which in turn will wake up
+ * the booster kthread.
+ */
+static void rcu_cpu_kthread_timer(unsigned long arg)
+{
+ struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, arg);
+ struct rcu_node *rnp = rdp->mynode;
+
+ atomic_or(rdp->grpmask, &rnp->wakemask);
+ invoke_rcu_node_kthread(rnp);
+}
+
+/*
+ * Drop to non-real-time priority and yield, but only after posting a
+ * timer that will cause us to regain our real-time priority if we
+ * remain preempted. Either way, we restore our real-time priority
+ * before returning.
+ */
+static void rcu_yield(void (*f)(unsigned long), unsigned long arg)
+{
+ struct sched_param sp;
+ struct timer_list yield_timer;
+
+ setup_timer_on_stack(&yield_timer, f, arg);
+ mod_timer(&yield_timer, jiffies + 2);
+ sp.sched_priority = 0;
+ sched_setscheduler_nocheck(current, SCHED_NORMAL, &sp);
+ set_user_nice(current, 19);
+ schedule();
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+ del_timer(&yield_timer);
+}
+
+/*
+ * Handle cases where the rcu_cpu_kthread() ends up on the wrong CPU.
+ * This can happen while the corresponding CPU is either coming online
+ * or going offline. We cannot wait until the CPU is fully online
+ * before starting the kthread, because the various notifier functions
+ * can wait for RCU grace periods. So we park rcu_cpu_kthread() until
+ * the corresponding CPU is online.
+ *
+ * Return 1 if the kthread needs to stop, 0 otherwise.
+ *
+ * Caller must disable bh. This function can momentarily enable it.
+ */
+static int rcu_cpu_kthread_should_stop(int cpu)
+{
+ while (cpu_is_offline(cpu) ||
+ !cpumask_equal(&current->cpus_allowed, cpumask_of(cpu)) ||
+ smp_processor_id() != cpu) {
+ if (kthread_should_stop())
+ return 1;
+ per_cpu(rcu_cpu_kthread_status, cpu) = RCU_KTHREAD_OFFCPU;
+ per_cpu(rcu_cpu_kthread_cpu, cpu) = raw_smp_processor_id();
+ local_bh_enable();
+ schedule_timeout_uninterruptible(1);
+ if (!cpumask_equal(&current->cpus_allowed, cpumask_of(cpu)))
+ set_cpus_allowed_ptr(current, cpumask_of(cpu));
+ local_bh_disable();
+ }
+ per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
+ return 0;
+}
+
+/*
+ * Per-CPU kernel thread that invokes RCU callbacks. This replaces the
+ * earlier RCU softirq.
+ */
+static int rcu_cpu_kthread(void *arg)
+{
+ int cpu = (int)(long)arg;
+ unsigned long flags;
+ int spincnt = 0;
+ unsigned int *statusp = &per_cpu(rcu_cpu_kthread_status, cpu);
+ char work;
+ char *workp = &per_cpu(rcu_cpu_has_work, cpu);
+
+ for (;;) {
+ *statusp = RCU_KTHREAD_WAITING;
+ rcu_wait(*workp != 0 || kthread_should_stop());
+ local_bh_disable();
+ if (rcu_cpu_kthread_should_stop(cpu)) {
+ local_bh_enable();
+ break;
+ }
+ *statusp = RCU_KTHREAD_RUNNING;
+ per_cpu(rcu_cpu_kthread_loops, cpu)++;
+ local_irq_save(flags);
+ work = *workp;
+ *workp = 0;
+ local_irq_restore(flags);
+ if (work)
+ rcu_kthread_do_work();
+ local_bh_enable();
+ if (*workp != 0)
+ spincnt++;
+ else
+ spincnt = 0;
+ if (spincnt > 10) {
+ *statusp = RCU_KTHREAD_YIELDING;
+ rcu_yield(rcu_cpu_kthread_timer, (unsigned long)cpu);
+ spincnt = 0;
+ }
+ }
+ *statusp = RCU_KTHREAD_STOPPED;
+ return 0;
+}
+
+/*
+ * Spawn a per-CPU kthread, setting up affinity and priority.
+ * Because the CPU hotplug lock is held, no other CPU will be attempting
+ * to manipulate rcu_cpu_kthread_task. There might be another CPU
+ * attempting to access it during boot, but the locking in kthread_bind()
+ * will enforce sufficient ordering.
+ *
+ * Please note that we cannot simply refuse to wake up the per-CPU
+ * kthread because kthreads are created in TASK_UNINTERRUPTIBLE state,
+ * which can result in softlockup complaints if the task ends up being
+ * idle for more than a couple of minutes.
+ *
+ * However, please note also that we cannot bind the per-CPU kthread to its
+ * CPU until that CPU is fully online. We also cannot wait until the
+ * CPU is fully online before we create its per-CPU kthread, as this would
+ * deadlock the system when CPU notifiers tried waiting for grace
+ * periods. So we bind the per-CPU kthread to its CPU only if the CPU
+ * is online. If its CPU is not yet fully online, then the code in
+ * rcu_cpu_kthread() will wait until it is fully online, and then do
+ * the binding.
+ */
+static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
+{
+ struct sched_param sp;
+ struct task_struct *t;
+
+ if (!rcu_kthreads_spawnable ||
+ per_cpu(rcu_cpu_kthread_task, cpu) != NULL)
+ return 0;
+ t = kthread_create(rcu_cpu_kthread, (void *)(long)cpu, "rcuc%d", cpu);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+ if (cpu_online(cpu))
+ kthread_bind(t, cpu);
+ per_cpu(rcu_cpu_kthread_cpu, cpu) = cpu;
+ WARN_ON_ONCE(per_cpu(rcu_cpu_kthread_task, cpu) != NULL);
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+ per_cpu(rcu_cpu_kthread_task, cpu) = t;
+ wake_up_process(t); /* Get to TASK_INTERRUPTIBLE quickly. */
+ return 0;
+}
+
+/*
+ * Per-rcu_node kthread, which is in charge of waking up the per-CPU
+ * kthreads when needed. We ignore requests to wake up kthreads
+ * for offline CPUs, which is OK because force_quiescent_state()
+ * takes care of this case.
+ */
+static int rcu_node_kthread(void *arg)
+{
+ int cpu;
+ unsigned long flags;
+ unsigned long mask;
+ struct rcu_node *rnp = (struct rcu_node *)arg;
+ struct sched_param sp;
+ struct task_struct *t;
+
+ for (;;) {
+ rnp->node_kthread_status = RCU_KTHREAD_WAITING;
+ rcu_wait(atomic_read(&rnp->wakemask) != 0);
+ rnp->node_kthread_status = RCU_KTHREAD_RUNNING;
+ raw_spin_lock_irqsave(&rnp->lock, flags);
+ mask = atomic_xchg(&rnp->wakemask, 0);
+ rcu_initiate_boost(rnp, flags); /* releases rnp->lock. */
+ for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1) {
+ if ((mask & 0x1) == 0)
+ continue;
+ preempt_disable();
+ t = per_cpu(rcu_cpu_kthread_task, cpu);
+ if (!cpu_online(cpu) || t == NULL) {
+ preempt_enable();
+ continue;
+ }
+ per_cpu(rcu_cpu_has_work, cpu) = 1;
+ sp.sched_priority = RCU_KTHREAD_PRIO;
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+ preempt_enable();
+ }
+ }
+ /* NOTREACHED */
+ rnp->node_kthread_status = RCU_KTHREAD_STOPPED;
+ return 0;
+}
+
+/*
+ * Set the per-rcu_node kthread's affinity to cover all CPUs that are
+ * served by the rcu_node in question. The CPU hotplug lock is still
+ * held, so the value of rnp->qsmaskinit will be stable.
+ *
+ * We don't include outgoingcpu in the affinity set, use -1 if there is
+ * no outgoing CPU. If there are no CPUs left in the affinity set,
+ * this function allows the kthread to execute on any CPU.
+ */
+static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
+{
+ cpumask_var_t cm;
+ int cpu;
+ unsigned long mask = rnp->qsmaskinit;
+
+ if (rnp->node_kthread_task == NULL)
+ return;
+ if (!alloc_cpumask_var(&cm, GFP_KERNEL))
+ return;
+ cpumask_clear(cm);
+ for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask >>= 1)
+ if ((mask & 0x1) && cpu != outgoingcpu)
+ cpumask_set_cpu(cpu, cm);
+ if (cpumask_weight(cm) == 0) {
+ cpumask_setall(cm);
+ for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++)
+ cpumask_clear_cpu(cpu, cm);
+ WARN_ON_ONCE(cpumask_weight(cm) == 0);
+ }
+ set_cpus_allowed_ptr(rnp->node_kthread_task, cm);
+ rcu_boost_kthread_setaffinity(rnp, cm);
+ free_cpumask_var(cm);
+}
+
+/*
+ * Spawn a per-rcu_node kthread, setting priority and affinity.
+ * Called during boot before online/offline can happen, or, if
+ * during runtime, with the main CPU-hotplug locks held. So only
+ * one of these can be executing at a time.
+ */
+static int __cpuinit rcu_spawn_one_node_kthread(struct rcu_state *rsp,
+ struct rcu_node *rnp)
+{
+ unsigned long flags;
+ int rnp_index = rnp - &rsp->node[0];
+ struct sched_param sp;
+ struct task_struct *t;
+
+ if (!rcu_kthreads_spawnable ||
+ rnp->qsmaskinit == 0)
+ return 0;
+ if (rnp->node_kthread_task == NULL) {
+ t = kthread_create(rcu_node_kthread, (void *)rnp,
+ "rcun%d", rnp_index);
+ if (IS_ERR(t))
+ return PTR_ERR(t);
+ raw_spin_lock_irqsave(&rnp->lock, flags);
+ rnp->node_kthread_task = t;
+ raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ sp.sched_priority = 99;
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+ wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
+ }
+ return rcu_spawn_one_boost_kthread(rsp, rnp, rnp_index);
+}
+
+/*
+ * Spawn all kthreads -- called as soon as the scheduler is running.
+ */
+static int __init rcu_spawn_kthreads(void)
+{
+ int cpu;
+ struct rcu_node *rnp;
+
+ rcu_kthreads_spawnable = 1;
+ for_each_possible_cpu(cpu) {
+ per_cpu(rcu_cpu_has_work, cpu) = 0;
+ if (cpu_online(cpu))
+ (void)rcu_spawn_one_cpu_kthread(cpu);
+ }
+ rnp = rcu_get_root(rcu_state);
+ (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
+ if (NUM_RCU_NODES > 1) {
+ rcu_for_each_leaf_node(rcu_state, rnp)
+ (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
+ }
+ return 0;
+}
+early_initcall(rcu_spawn_kthreads);
+
+static void __cpuinit rcu_prepare_kthreads(int cpu)
+{
+ struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu);
+ struct rcu_node *rnp = rdp->mynode;
+
+ /* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */
+ if (rcu_kthreads_spawnable) {
+ (void)rcu_spawn_one_cpu_kthread(cpu);
+ if (rnp->node_kthread_task == NULL)
+ (void)rcu_spawn_one_node_kthread(rcu_state, rnp);
+ }
+}
+
#else /* #ifdef CONFIG_RCU_BOOST */
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
@@ -1319,24 +1701,33 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
-static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp,
- cpumask_var_t cm)
+static void invoke_rcu_callbacks_kthread(void)
{
+ WARN_ON_ONCE(1);
}
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp)
{
}
-static void __init rcu_init_boost_waitqueue(struct rcu_node *rnp)
+#ifdef CONFIG_HOTPLUG_CPU
+
+static void rcu_stop_cpu_kthread(int cpu)
{
}
-static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
- struct rcu_node *rnp,
- int rnp_index)
+#endif /* #ifdef CONFIG_HOTPLUG_CPU */
+
+static void rcu_node_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
+{
+}
+
+static void rcu_cpu_kthread_setrt(int cpu, int to_rt)
+{
+}
+
+static void __cpuinit rcu_prepare_kthreads(int cpu)
{
- return 0;
}
#endif /* #else #ifdef CONFIG_RCU_BOOST */
@@ -1513,14 +1904,13 @@ static DEFINE_PER_CPU(unsigned long, rcu_dyntick_holdoff);
*
* Because it is not legal to invoke rcu_process_callbacks() with irqs
* disabled, we do one pass of force_quiescent_state(), then do a
- * invoke_rcu_cpu_kthread() to cause rcu_process_callbacks() to be invoked
+ * invoke_rcu_core() 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 snap;
- int snap_nmi;
int thatcpu;
/* Check for being in the holdoff period. */
@@ -1531,10 +1921,10 @@ int rcu_needs_cpu(int cpu)
for_each_online_cpu(thatcpu) {
if (thatcpu == cpu)
continue;
- snap = per_cpu(rcu_dynticks, thatcpu).dynticks;
- snap_nmi = per_cpu(rcu_dynticks, thatcpu).dynticks_nmi;
+ snap = atomic_add_return(0, &per_cpu(rcu_dynticks,
+ thatcpu).dynticks);
smp_mb(); /* Order sampling of snap with end of grace period. */
- if (((snap & 0x1) != 0) || ((snap_nmi & 0x1) != 0)) {
+ if ((snap & 0x1) != 0) {
per_cpu(rcu_dyntick_drain, cpu) = 0;
per_cpu(rcu_dyntick_holdoff, cpu) = jiffies - 1;
return rcu_needs_cpu_quick_check(cpu);
@@ -1565,7 +1955,7 @@ int rcu_needs_cpu(int cpu)
/* If RCU callbacks are still pending, RCU still needs this CPU. */
if (c)
- invoke_rcu_cpu_kthread();
+ invoke_rcu_core();
return c;
}
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index aa0fd72b4bc7..4e144876dc68 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -46,6 +46,8 @@
#define RCU_TREE_NONCORE
#include "rcutree.h"
+#ifdef CONFIG_RCU_BOOST
+
DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu);
DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
@@ -58,6 +60,8 @@ static char convert_kthread_status(unsigned int kthread_status)
return "SRWOY"[kthread_status];
}
+#endif /* #ifdef CONFIG_RCU_BOOST */
+
static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
{
if (!rdp->beenonline)
@@ -69,14 +73,14 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
rdp->passed_quiesc, rdp->passed_quiesc_completed,
rdp->qs_pending);
#ifdef CONFIG_NO_HZ
- seq_printf(m, " dt=%d/%d dn=%d df=%lu",
- rdp->dynticks->dynticks,
+ seq_printf(m, " dt=%d/%d/%d df=%lu",
+ atomic_read(&rdp->dynticks->dynticks),
rdp->dynticks->dynticks_nesting,
- rdp->dynticks->dynticks_nmi,
+ rdp->dynticks->dynticks_nmi_nesting,
rdp->dynticks_fqs);
#endif /* #ifdef CONFIG_NO_HZ */
seq_printf(m, " of=%lu ri=%lu", rdp->offline_fqs, rdp->resched_ipi);
- seq_printf(m, " ql=%ld qs=%c%c%c%c kt=%d/%c/%d ktl=%x b=%ld",
+ seq_printf(m, " ql=%ld qs=%c%c%c%c",
rdp->qlen,
".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
rdp->nxttail[RCU_NEXT_TAIL]],
@@ -84,13 +88,16 @@ static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
rdp->nxttail[RCU_NEXT_READY_TAIL]],
".W"[rdp->nxttail[RCU_DONE_TAIL] !=
rdp->nxttail[RCU_WAIT_TAIL]],
- ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]],
+ ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
+#ifdef CONFIG_RCU_BOOST
+ seq_printf(m, " kt=%d/%c/%d ktl=%x",
per_cpu(rcu_cpu_has_work, rdp->cpu),
convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
rdp->cpu)),
per_cpu(rcu_cpu_kthread_cpu, rdp->cpu),
- per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff,
- rdp->blimit);
+ per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
+#endif /* #ifdef CONFIG_RCU_BOOST */
+ seq_printf(m, " b=%ld", rdp->blimit);
seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
}
@@ -141,24 +148,27 @@ static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
rdp->qs_pending);
#ifdef CONFIG_NO_HZ
seq_printf(m, ",%d,%d,%d,%lu",
- rdp->dynticks->dynticks,
+ atomic_read(&rdp->dynticks->dynticks),
rdp->dynticks->dynticks_nesting,
- rdp->dynticks->dynticks_nmi,
+ rdp->dynticks->dynticks_nmi_nesting,
rdp->dynticks_fqs);
#endif /* #ifdef CONFIG_NO_HZ */
seq_printf(m, ",%lu,%lu", rdp->offline_fqs, rdp->resched_ipi);
- seq_printf(m, ",%ld,\"%c%c%c%c\",%d,\"%c\",%ld", rdp->qlen,
+ seq_printf(m, ",%ld,\"%c%c%c%c\"", rdp->qlen,
".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
rdp->nxttail[RCU_NEXT_TAIL]],
".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
rdp->nxttail[RCU_NEXT_READY_TAIL]],
".W"[rdp->nxttail[RCU_DONE_TAIL] !=
rdp->nxttail[RCU_WAIT_TAIL]],
- ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]],
+ ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
+#ifdef CONFIG_RCU_BOOST
+ seq_printf(m, ",%d,\"%c\"",
per_cpu(rcu_cpu_has_work, rdp->cpu),
convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
- rdp->cpu)),
- rdp->blimit);
+ rdp->cpu)));
+#endif /* #ifdef CONFIG_RCU_BOOST */
+ seq_printf(m, ",%ld", rdp->blimit);
seq_printf(m, ",%lu,%lu,%lu\n",
rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
}
@@ -167,9 +177,13 @@ static int show_rcudata_csv(struct seq_file *m, void *unused)
{
seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pqc\",\"pq\",");
#ifdef CONFIG_NO_HZ
- seq_puts(m, "\"dt\",\"dt nesting\",\"dn\",\"df\",");
+ seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
#endif /* #ifdef CONFIG_NO_HZ */
- seq_puts(m, "\"of\",\"ri\",\"ql\",\"b\",\"ci\",\"co\",\"ca\"\n");
+ seq_puts(m, "\"of\",\"ri\",\"ql\",\"qs\"");
+#ifdef CONFIG_RCU_BOOST
+ seq_puts(m, "\"kt\",\"ktl\"");
+#endif /* #ifdef CONFIG_RCU_BOOST */
+ seq_puts(m, ",\"b\",\"ci\",\"co\",\"ca\"\n");
#ifdef CONFIG_TREE_PREEMPT_RCU
seq_puts(m, "\"rcu_preempt:\"\n");
PRINT_RCU_DATA(rcu_preempt_data, print_one_rcu_data_csv, m);
diff --git a/kernel/sched.c b/kernel/sched.c
index fd18f395a1bf..59252754fbe0 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -605,10 +605,10 @@ static inline int cpu_of(struct rq *rq)
/*
* Return the group to which this tasks belongs.
*
- * We use task_subsys_state_check() and extend the RCU verification
- * with lockdep_is_held(&p->pi_lock) because cpu_cgroup_attach()
- * holds that lock for each task it moves into the cgroup. Therefore
- * by holding that lock, we pin the task to the current cgroup.
+ * We use task_subsys_state_check() and extend the RCU verification with
+ * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each
+ * task it moves into the cgroup. Therefore by holding either of those locks,
+ * we pin the task to the current cgroup.
*/
static inline struct task_group *task_group(struct task_struct *p)
{
@@ -616,7 +616,8 @@ static inline struct task_group *task_group(struct task_struct *p)
struct cgroup_subsys_state *css;
css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
- lockdep_is_held(&p->pi_lock));
+ lockdep_is_held(&p->pi_lock) ||
+ lockdep_is_held(&task_rq(p)->lock));
tg = container_of(css, struct task_group, css);
return autogroup_task_group(p, tg);
@@ -2200,6 +2201,16 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
!(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
#ifdef CONFIG_LOCKDEP
+ /*
+ * The caller should hold either p->pi_lock or rq->lock, when changing
+ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
+ *
+ * sched_move_task() holds both and thus holding either pins the cgroup,
+ * see set_task_rq().
+ *
+ * Furthermore, all task_rq users should acquire both locks, see
+ * task_rq_lock().
+ */
WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
lockdep_is_held(&task_rq(p)->lock)));
#endif
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 08e937496b24..b03cd89fee20 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1096,7 +1096,7 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag
* to move current somewhere else, making room for our non-migratable
* task.
*/
- if (p->prio == rq->curr->prio && !need_resched())
+ if (p->prio == rq->curr->prio && !test_tsk_need_resched(rq->curr))
check_preempt_equal_prio(rq, p);
#endif
}
@@ -1239,6 +1239,10 @@ static int find_lowest_rq(struct task_struct *task)
int this_cpu = smp_processor_id();
int cpu = task_cpu(task);
+ /* Make sure the mask is initialized first */
+ if (unlikely(!lowest_mask))
+ return -1;
+
if (task->rt.nr_cpus_allowed == 1)
return -1; /* No other targets possible */
diff --git a/kernel/signal.c b/kernel/signal.c
index 86c32b884f8e..ff7678603328 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2365,7 +2365,7 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
/**
* sys_rt_sigprocmask - change the list of currently blocked signals
* @how: whether to add, remove, or set signals
- * @set: stores pending signals
+ * @nset: stores pending signals
* @oset: previous value of signal mask if non-null
* @sigsetsize: size of sigset_t type
*/
diff --git a/kernel/smp.c b/kernel/smp.c
index 73a195193558..fb67dfa8394e 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -74,7 +74,7 @@ static struct notifier_block __cpuinitdata hotplug_cfd_notifier = {
.notifier_call = hotplug_cfd,
};
-static int __cpuinit init_call_single_data(void)
+void __init call_function_init(void)
{
void *cpu = (void *)(long)smp_processor_id();
int i;
@@ -88,10 +88,7 @@ static int __cpuinit init_call_single_data(void)
hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
register_cpu_notifier(&hotplug_cfd_notifier);
-
- return 0;
}
-early_initcall(init_call_single_data);
/*
* csd_lock/csd_unlock used to serialize access to per-cpu csd resources
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 13960170cad4..40cf63ddd4b3 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -58,7 +58,7 @@ DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
char *softirq_to_name[NR_SOFTIRQS] = {
"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
- "TASKLET", "SCHED", "HRTIMER"
+ "TASKLET", "SCHED", "HRTIMER", "RCU"
};
/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 4fc92445a29c..f175d98bd355 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -938,6 +938,12 @@ static struct ctl_table kern_table[] = {
},
#endif
#ifdef CONFIG_PERF_EVENTS
+ /*
+ * User-space scripts rely on the existence of this file
+ * as a feature check for perf_events being enabled.
+ *
+ * So it's an ABI, do not remove!
+ */
{
.procname = "perf_event_paranoid",
.data = &sysctl_perf_event_paranoid,
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 9ffea360a778..fc0f22005417 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -285,16 +285,18 @@ ret:
static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
{
struct listener_list *listeners;
- struct listener *s, *tmp;
+ struct listener *s, *tmp, *s2;
unsigned int cpu;
if (!cpumask_subset(mask, cpu_possible_mask))
return -EINVAL;
+ s = NULL;
if (isadd == REGISTER) {
for_each_cpu(cpu, mask) {
- s = kmalloc_node(sizeof(struct listener), GFP_KERNEL,
- cpu_to_node(cpu));
+ if (!s)
+ s = kmalloc_node(sizeof(struct listener),
+ GFP_KERNEL, cpu_to_node(cpu));
if (!s)
goto cleanup;
s->pid = pid;
@@ -303,9 +305,16 @@ static int add_del_listener(pid_t pid, const struct cpumask *mask, int isadd)
listeners = &per_cpu(listener_array, cpu);
down_write(&listeners->sem);
+ list_for_each_entry_safe(s2, tmp, &listeners->list, list) {
+ if (s2->pid == pid)
+ goto next_cpu;
+ }
list_add(&s->list, &listeners->list);
+ s = NULL;
+next_cpu:
up_write(&listeners->sem);
}
+ kfree(s);
return 0;
}
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 2d966244ea60..59f369f98a04 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -42,15 +42,75 @@ static struct alarm_base {
clockid_t base_clockid;
} alarm_bases[ALARM_NUMTYPE];
+/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
+static ktime_t freezer_delta;
+static DEFINE_SPINLOCK(freezer_delta_lock);
+
#ifdef CONFIG_RTC_CLASS
/* rtc timer and device for setting alarm wakeups at suspend */
static struct rtc_timer rtctimer;
static struct rtc_device *rtcdev;
-#endif
+static DEFINE_SPINLOCK(rtcdev_lock);
-/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
-static ktime_t freezer_delta;
-static DEFINE_SPINLOCK(freezer_delta_lock);
+/**
+ * has_wakealarm - check rtc device has wakealarm ability
+ * @dev: current device
+ * @name_ptr: name to be returned
+ *
+ * This helper function checks to see if the rtc device can wake
+ * from suspend.
+ */
+static int has_wakealarm(struct device *dev, void *name_ptr)
+{
+ struct rtc_device *candidate = to_rtc_device(dev);
+
+ if (!candidate->ops->set_alarm)
+ return 0;
+ if (!device_may_wakeup(candidate->dev.parent))
+ return 0;
+
+ *(const char **)name_ptr = dev_name(dev);
+ return 1;
+}
+
+/**
+ * alarmtimer_get_rtcdev - Return selected rtcdevice
+ *
+ * This function returns the rtc device to use for wakealarms.
+ * If one has not already been chosen, it checks to see if a
+ * functional rtc device is available.
+ */
+static struct rtc_device *alarmtimer_get_rtcdev(void)
+{
+ struct device *dev;
+ char *str;
+ unsigned long flags;
+ struct rtc_device *ret;
+
+ spin_lock_irqsave(&rtcdev_lock, flags);
+ if (!rtcdev) {
+ /* Find an rtc device and init the rtc_timer */
+ dev = class_find_device(rtc_class, NULL, &str, has_wakealarm);
+ /* If we have a device then str is valid. See has_wakealarm() */
+ if (dev) {
+ rtcdev = rtc_class_open(str);
+ /*
+ * Drop the reference we got in class_find_device,
+ * rtc_open takes its own.
+ */
+ put_device(dev);
+ rtc_timer_init(&rtctimer, NULL, NULL);
+ }
+ }
+ ret = rtcdev;
+ spin_unlock_irqrestore(&rtcdev_lock, flags);
+
+ return ret;
+}
+#else
+#define alarmtimer_get_rtcdev() (0)
+#define rtcdev (0)
+#endif
/**
@@ -166,6 +226,7 @@ static int alarmtimer_suspend(struct device *dev)
struct rtc_time tm;
ktime_t min, now;
unsigned long flags;
+ struct rtc_device *rtc;
int i;
spin_lock_irqsave(&freezer_delta_lock, flags);
@@ -173,8 +234,9 @@ static int alarmtimer_suspend(struct device *dev)
freezer_delta = ktime_set(0, 0);
spin_unlock_irqrestore(&freezer_delta_lock, flags);
+ rtc = rtcdev;
/* If we have no rtcdev, just return */
- if (!rtcdev)
+ if (!rtc)
return 0;
/* Find the soonest timer to expire*/
@@ -199,12 +261,12 @@ static int alarmtimer_suspend(struct device *dev)
WARN_ON(min.tv64 < NSEC_PER_SEC);
/* Setup an rtc timer to fire that far in the future */
- rtc_timer_cancel(rtcdev, &rtctimer);
- rtc_read_time(rtcdev, &tm);
+ rtc_timer_cancel(rtc, &rtctimer);
+ rtc_read_time(rtc, &tm);
now = rtc_tm_to_ktime(tm);
now = ktime_add(now, min);
- rtc_timer_start(rtcdev, &rtctimer, now, ktime_set(0, 0));
+ rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
return 0;
}
@@ -322,6 +384,9 @@ static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
{
clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
+ if (!alarmtimer_get_rtcdev())
+ return -ENOTSUPP;
+
return hrtimer_get_res(baseid, tp);
}
@@ -336,6 +401,9 @@ static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
{
struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
+ if (!alarmtimer_get_rtcdev())
+ return -ENOTSUPP;
+
*tp = ktime_to_timespec(base->gettime());
return 0;
}
@@ -351,6 +419,9 @@ static int alarm_timer_create(struct k_itimer *new_timer)
enum alarmtimer_type type;
struct alarm_base *base;
+ if (!alarmtimer_get_rtcdev())
+ return -ENOTSUPP;
+
if (!capable(CAP_WAKE_ALARM))
return -EPERM;
@@ -385,6 +456,9 @@ static void alarm_timer_get(struct k_itimer *timr,
*/
static int alarm_timer_del(struct k_itimer *timr)
{
+ if (!rtcdev)
+ return -ENOTSUPP;
+
alarm_cancel(&timr->it.alarmtimer);
return 0;
}
@@ -402,6 +476,9 @@ static int alarm_timer_set(struct k_itimer *timr, int flags,
struct itimerspec *new_setting,
struct itimerspec *old_setting)
{
+ if (!rtcdev)
+ return -ENOTSUPP;
+
/* Save old values */
old_setting->it_interval =
ktime_to_timespec(timr->it.alarmtimer.period);
@@ -541,6 +618,9 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
int ret = 0;
struct restart_block *restart;
+ if (!alarmtimer_get_rtcdev())
+ return -ENOTSUPP;
+
if (!capable(CAP_WAKE_ALARM))
return -EPERM;
@@ -638,65 +718,3 @@ static int __init alarmtimer_init(void)
}
device_initcall(alarmtimer_init);
-#ifdef CONFIG_RTC_CLASS
-/**
- * has_wakealarm - check rtc device has wakealarm ability
- * @dev: current device
- * @name_ptr: name to be returned
- *
- * This helper function checks to see if the rtc device can wake
- * from suspend.
- */
-static int __init has_wakealarm(struct device *dev, void *name_ptr)
-{
- struct rtc_device *candidate = to_rtc_device(dev);
-
- if (!candidate->ops->set_alarm)
- return 0;
- if (!device_may_wakeup(candidate->dev.parent))
- return 0;
-
- *(const char **)name_ptr = dev_name(dev);
- return 1;
-}
-
-/**
- * alarmtimer_init_late - Late initializing of alarmtimer code
- *
- * This function locates a rtc device to use for wakealarms.
- * Run as late_initcall to make sure rtc devices have been
- * registered.
- */
-static int __init alarmtimer_init_late(void)
-{
- struct device *dev;
- char *str;
-
- /* Find an rtc device and init the rtc_timer */
- dev = class_find_device(rtc_class, NULL, &str, has_wakealarm);
- /* If we have a device then str is valid. See has_wakealarm() */
- if (dev) {
- rtcdev = rtc_class_open(str);
- /*
- * Drop the reference we got in class_find_device,
- * rtc_open takes its own.
- */
- put_device(dev);
- }
- if (!rtcdev) {
- printk(KERN_WARNING "No RTC device found, ALARM timers will"
- " not wake from suspend");
- }
- rtc_timer_init(&rtctimer, NULL, NULL);
-
- return 0;
-}
-#else
-static int __init alarmtimer_init_late(void)
-{
- printk(KERN_WARNING "Kernel not built with RTC support, ALARM timers"
- " will not wake from suspend");
- return 0;
-}
-#endif
-late_initcall(alarmtimer_init_late);
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index c027d4f602f1..e4c699dfa4e8 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -182,7 +182,10 @@ void clockevents_register_device(struct clock_event_device *dev)
unsigned long flags;
BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
- BUG_ON(!dev->cpumask);
+ if (!dev->cpumask) {
+ WARN_ON(num_possible_cpus() > 1);
+ dev->cpumask = cpumask_of(smp_processor_id());
+ }
raw_spin_lock_irqsave(&clockevents_lock, flags);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 1c95fd677328..e0980f0d9a0a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -185,7 +185,6 @@ static struct clocksource *watchdog;
static struct timer_list watchdog_timer;
static DECLARE_WORK(watchdog_work, clocksource_watchdog_work);
static DEFINE_SPINLOCK(watchdog_lock);
-static cycle_t watchdog_last;
static int watchdog_running;
static int clocksource_watchdog_kthread(void *data);
@@ -254,11 +253,6 @@ static void clocksource_watchdog(unsigned long data)
if (!watchdog_running)
goto out;
- wdnow = watchdog->read(watchdog);
- wd_nsec = clocksource_cyc2ns((wdnow - watchdog_last) & watchdog->mask,
- watchdog->mult, watchdog->shift);
- watchdog_last = wdnow;
-
list_for_each_entry(cs, &watchdog_list, wd_list) {
/* Clocksource already marked unstable? */
@@ -268,19 +262,28 @@ static void clocksource_watchdog(unsigned long data)
continue;
}
+ local_irq_disable();
csnow = cs->read(cs);
+ wdnow = watchdog->read(watchdog);
+ local_irq_enable();
/* Clocksource initialized ? */
if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
cs->flags |= CLOCK_SOURCE_WATCHDOG;
- cs->wd_last = csnow;
+ cs->wd_last = wdnow;
+ cs->cs_last = csnow;
continue;
}
- /* Check the deviation from the watchdog clocksource. */
- cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
+ wd_nsec = clocksource_cyc2ns((wdnow - cs->wd_last) & watchdog->mask,
+ watchdog->mult, watchdog->shift);
+
+ cs_nsec = clocksource_cyc2ns((csnow - cs->cs_last) &
cs->mask, cs->mult, cs->shift);
- cs->wd_last = csnow;
+ cs->cs_last = csnow;
+ cs->wd_last = wdnow;
+
+ /* Check the deviation from the watchdog clocksource. */
if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
clocksource_unstable(cs, cs_nsec - wd_nsec);
continue;
@@ -318,7 +321,6 @@ static inline void clocksource_start_watchdog(void)
return;
init_timer(&watchdog_timer);
watchdog_timer.function = clocksource_watchdog;
- watchdog_last = watchdog->read(watchdog);
watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
add_timer_on(&watchdog_timer, cpumask_first(cpu_online_mask));
watchdog_running = 1;
diff --git a/kernel/timer.c b/kernel/timer.c
index fd6198692b57..8cff36119e4d 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -749,16 +749,15 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
unsigned long expires_limit, mask;
int bit;
- expires_limit = expires;
-
if (timer->slack >= 0) {
expires_limit = expires + timer->slack;
} else {
- unsigned long now = jiffies;
+ long delta = expires - jiffies;
+
+ if (delta < 256)
+ return expires;
- /* No slack, if already expired else auto slack 0.4% */
- if (time_after(expires, now))
- expires_limit = expires + (expires - now)/256;
+ expires_limit = expires + delta / 256;
}
mask = expires ^ expires_limit;
if (mask == 0)
@@ -795,6 +794,8 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
+ expires = apply_slack(timer, expires);
+
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
@@ -803,8 +804,6 @@ int mod_timer(struct timer_list *timer, unsigned long expires)
if (timer_pending(timer) && timer->expires == expires)
return 1;
- expires = apply_slack(timer, expires);
-
return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
}
EXPORT_SYMBOL(mod_timer);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d017c2c82c44..908038f57440 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -109,12 +109,18 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
static void ftrace_global_list_func(unsigned long ip,
unsigned long parent_ip)
{
- struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+ struct ftrace_ops *op;
+
+ if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+ return;
+ trace_recursion_set(TRACE_GLOBAL_BIT);
+ op = rcu_dereference_raw(ftrace_global_list); /*see above*/
while (op != &ftrace_list_end) {
op->func(ip, parent_ip);
op = rcu_dereference_raw(op->next); /*see above*/
};
+ trace_recursion_clear(TRACE_GLOBAL_BIT);
}
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
@@ -1638,12 +1644,12 @@ static void ftrace_startup_enable(int command)
ftrace_run_update_code(command);
}
-static void ftrace_startup(struct ftrace_ops *ops, int command)
+static int ftrace_startup(struct ftrace_ops *ops, int command)
{
bool hash_enable = true;
if (unlikely(ftrace_disabled))
- return;
+ return -ENODEV;
ftrace_start_up++;
command |= FTRACE_ENABLE_CALLS;
@@ -1662,6 +1668,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command)
ftrace_hash_rec_enable(ops, 1);
ftrace_startup_enable(command);
+
+ return 0;
}
static void ftrace_shutdown(struct ftrace_ops *ops, int command)
@@ -2501,7 +2509,7 @@ static void __enable_ftrace_function_probe(void)
ret = __register_ftrace_function(&trace_probe_ops);
if (!ret)
- ftrace_startup(&trace_probe_ops, 0);
+ ret = ftrace_startup(&trace_probe_ops, 0);
ftrace_probe_registered = 1;
}
@@ -2732,7 +2740,7 @@ static int ftrace_process_regex(struct ftrace_hash *hash,
{
char *func, *command, *next = buff;
struct ftrace_func_command *p;
- int ret;
+ int ret = -EINVAL;
func = strsep(&next, ":");
@@ -3322,6 +3330,7 @@ static int ftrace_process_locs(struct module *mod,
{
unsigned long *p;
unsigned long addr;
+ unsigned long flags;
mutex_lock(&ftrace_lock);
p = start;
@@ -3338,7 +3347,13 @@ static int ftrace_process_locs(struct module *mod,
ftrace_record_ip(addr);
}
+ /*
+ * Disable interrupts to prevent interrupts from executing
+ * code that is being modified.
+ */
+ local_irq_save(flags);
ftrace_update_code(mod);
+ local_irq_restore(flags);
mutex_unlock(&ftrace_lock);
return 0;
@@ -3466,7 +3481,11 @@ device_initcall(ftrace_nodyn_init);
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_enable(int command) { }
/* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command) do { } while (0)
+# define ftrace_startup(ops, command) \
+ ({ \
+ (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
+ 0; \
+ })
# define ftrace_shutdown(ops, command) do { } while (0)
# define ftrace_startup_sysctl() do { } while (0)
# define ftrace_shutdown_sysctl() do { } while (0)
@@ -3484,6 +3503,10 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
{
struct ftrace_ops *op;
+ if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+ return;
+
+ trace_recursion_set(TRACE_INTERNAL_BIT);
/*
* Some of the ops may be dynamically allocated,
* they must be freed after a synchronize_sched().
@@ -3496,6 +3519,7 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
op = rcu_dereference_raw(op->next);
};
preempt_enable_notrace();
+ trace_recursion_clear(TRACE_INTERNAL_BIT);
}
static void clear_ftrace_swapper(void)
@@ -3799,7 +3823,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
ret = __register_ftrace_function(ops);
if (!ret)
- ftrace_startup(ops, 0);
+ ret = ftrace_startup(ops, 0);
out_unlock:
@@ -4045,7 +4069,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
ftrace_graph_return = retfunc;
ftrace_graph_entry = entryfunc;
- ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+ ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
out:
mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0ef7b4b2a1f7..b0c7aa407943 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2216,7 +2216,7 @@ static noinline void trace_recursive_fail(void)
printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:"
"HC[%lu]:SC[%lu]:NMI[%lu]\n",
- current->trace_recursion,
+ trace_recursion_buffer(),
hardirq_count() >> HARDIRQ_SHIFT,
softirq_count() >> SOFTIRQ_SHIFT,
in_nmi());
@@ -2226,9 +2226,9 @@ static noinline void trace_recursive_fail(void)
static inline int trace_recursive_lock(void)
{
- current->trace_recursion++;
+ trace_recursion_inc();
- if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
+ if (likely(trace_recursion_buffer() < TRACE_RECURSIVE_DEPTH))
return 0;
trace_recursive_fail();
@@ -2238,9 +2238,9 @@ static inline int trace_recursive_lock(void)
static inline void trace_recursive_unlock(void)
{
- WARN_ON_ONCE(!current->trace_recursion);
+ WARN_ON_ONCE(!trace_recursion_buffer());
- current->trace_recursion--;
+ trace_recursion_dec();
}
#else
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 6b69c4bd306f..229f8591f61d 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -784,4 +784,19 @@ extern const char *__stop___trace_bprintk_fmt[];
FTRACE_ENTRY(call, struct_name, id, PARAMS(tstruct), PARAMS(print))
#include "trace_entries.h"
+/* Only current can touch trace_recursion */
+#define trace_recursion_inc() do { (current)->trace_recursion++; } while (0)
+#define trace_recursion_dec() do { (current)->trace_recursion--; } while (0)
+
+/* Ring buffer has the 10 LSB bits to count */
+#define trace_recursion_buffer() ((current)->trace_recursion & 0x3ff)
+
+/* for function tracing recursion */
+#define TRACE_INTERNAL_BIT (1<<11)
+#define TRACE_GLOBAL_BIT (1<<12)
+
+#define trace_recursion_set(bit) do { (current)->trace_recursion |= (bit); } while (0)
+#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(bit); } while (0)
+#define trace_recursion_test(bit) ((current)->trace_recursion & (bit))
+
#endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 2fe110341359..686ec399f2a8 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1657,7 +1657,12 @@ static struct ftrace_ops trace_ops __initdata =
static __init void event_trace_self_test_with_function(void)
{
- register_ftrace_function(&trace_ops);
+ int ret;
+ ret = register_ftrace_function(&trace_ops);
+ if (WARN_ON(ret < 0)) {
+ pr_info("Failed to enable function tracer for event tests\n");
+ return;
+ }
pr_info("Running tests again, along with the function tracer\n");
event_trace_self_tests();
unregister_ftrace_function(&trace_ops);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f925c45f0afa..27d13b36b8be 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1870,8 +1870,12 @@ fs_initcall(init_kprobe_trace);
#ifdef CONFIG_FTRACE_STARTUP_TEST
-static int kprobe_trace_selftest_target(int a1, int a2, int a3,
- int a4, int a5, int a6)
+/*
+ * The "__used" keeps gcc from removing the function symbol
+ * from the kallsyms table.
+ */
+static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
+ int a4, int a5, int a6)
{
return a1 + a2 + a3 + a4 + a5 + a6;
}
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cf535ccedc86..e37de492a9e1 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -353,6 +353,33 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
}
EXPORT_SYMBOL(ftrace_print_symbols_seq);
+#if BITS_PER_LONG == 32
+const char *
+ftrace_print_symbols_seq_u64(struct trace_seq *p, unsigned long long val,
+ const struct trace_print_flags_u64 *symbol_array)
+{
+ int i;
+ const char *ret = p->buffer + p->len;
+
+ for (i = 0; symbol_array[i].name; i++) {
+
+ if (val != symbol_array[i].mask)
+ continue;
+
+ trace_seq_puts(p, symbol_array[i].name);
+ break;
+ }
+
+ if (!p->len)
+ trace_seq_printf(p, "0x%llx", val);
+
+ trace_seq_putc(p, 0);
+
+ return ret;
+}
+EXPORT_SYMBOL(ftrace_print_symbols_seq_u64);
+#endif
+
const char *
ftrace_print_hex_seq(struct trace_seq *p, const unsigned char *buf, int buf_len)
{
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index dff763b7baf1..1f06468a10d7 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -240,13 +240,10 @@ static const char **find_next(void *v, loff_t *pos)
const char **fmt = v;
int start_index;
- if (!fmt)
- fmt = __start___trace_bprintk_fmt + *pos;
-
start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt;
if (*pos < start_index)
- return fmt;
+ return __start___trace_bprintk_fmt + *pos;
return find_next_mod_format(start_index, v, fmt, pos);
}
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 7daa4b072e9f..3d0c56ad4792 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -415,15 +415,13 @@ static void watchdog_nmi_disable(int cpu) { return; }
#endif /* CONFIG_HARDLOCKUP_DETECTOR */
/* prepare/enable/disable routines */
-static int watchdog_prepare_cpu(int cpu)
+static void watchdog_prepare_cpu(int cpu)
{
struct hrtimer *hrtimer = &per_cpu(watchdog_hrtimer, cpu);
WARN_ON(per_cpu(softlockup_watchdog, cpu));
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
-
- return 0;
}
static int watchdog_enable(int cpu)
@@ -542,17 +540,16 @@ static int __cpuinit
cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
- int err = 0;
switch (action) {
case CPU_UP_PREPARE:
case CPU_UP_PREPARE_FROZEN:
- err = watchdog_prepare_cpu(hotcpu);
+ watchdog_prepare_cpu(hotcpu);
break;
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
if (watchdog_enabled)
- err = watchdog_enable(hotcpu);
+ watchdog_enable(hotcpu);
break;
#ifdef CONFIG_HOTPLUG_CPU
case CPU_UP_CANCELED: