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authorRafael J. Wysocki <rjw@sisk.pl>2011-12-06 22:12:50 +0100
committerRafael J. Wysocki <rjw@sisk.pl>2011-12-06 22:12:50 +0100
commit2e8e89e392c62636ee33532358607baef2863173 (patch)
treed995a25c68eef57dea580b0f06ba8af76758775a /kernel
parent0c6aebe31861c470c8cfbfdfdfd72d1369a6440b (diff)
parentd310310cbff18ec385c6ab4d58f33b100192a96a (diff)
downloadop-kernel-dev-2e8e89e392c62636ee33532358607baef2863173.zip
op-kernel-dev-2e8e89e392c62636ee33532358607baef2863173.tar.gz
Merge branch 'pm-freezer' into pm-sleep
* pm-freezer: (26 commits) Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer Freezer: fix more fallout from the thaw_process rename freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup_freezer.c63
-rw-r--r--kernel/exit.c3
-rw-r--r--kernel/fork.c1
-rw-r--r--kernel/freezer.c203
-rw-r--r--kernel/kthread.c27
-rw-r--r--kernel/power/hibernate.c15
-rw-r--r--kernel/power/process.c77
-rw-r--r--kernel/power/suspend.c8
-rw-r--r--kernel/power/user.c4
9 files changed, 196 insertions, 205 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 5e828a2..e411a60 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -48,19 +48,17 @@ static inline struct freezer *task_freezer(struct task_struct *task)
struct freezer, css);
}
-static inline int __cgroup_freezing_or_frozen(struct task_struct *task)
+bool cgroup_freezing(struct task_struct *task)
{
- enum freezer_state state = task_freezer(task)->state;
- return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
-}
+ enum freezer_state state;
+ bool ret;
-int cgroup_freezing_or_frozen(struct task_struct *task)
-{
- int result;
- task_lock(task);
- result = __cgroup_freezing_or_frozen(task);
- task_unlock(task);
- return result;
+ rcu_read_lock();
+ state = task_freezer(task)->state;
+ ret = state == CGROUP_FREEZING || state == CGROUP_FROZEN;
+ rcu_read_unlock();
+
+ return ret;
}
/*
@@ -102,9 +100,6 @@ struct cgroup_subsys freezer_subsys;
* freezer_can_attach():
* cgroup_mutex (held by caller of can_attach)
*
- * cgroup_freezing_or_frozen():
- * task->alloc_lock (to get task's cgroup)
- *
* freezer_fork() (preserving fork() performance means can't take cgroup_mutex):
* freezer->lock
* sighand->siglock (if the cgroup is freezing)
@@ -130,7 +125,7 @@ struct cgroup_subsys freezer_subsys;
* write_lock css_set_lock (cgroup iterator start)
* task->alloc_lock
* read_lock css_set_lock (cgroup iterator start)
- * task->alloc_lock (inside thaw_process(), prevents race with refrigerator())
+ * task->alloc_lock (inside __thaw_task(), prevents race with refrigerator())
* sighand->siglock
*/
static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
@@ -150,7 +145,11 @@ static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
static void freezer_destroy(struct cgroup_subsys *ss,
struct cgroup *cgroup)
{
- kfree(cgroup_freezer(cgroup));
+ struct freezer *freezer = cgroup_freezer(cgroup);
+
+ if (freezer->state != CGROUP_THAWED)
+ atomic_dec(&system_freezing_cnt);
+ kfree(freezer);
}
/*
@@ -177,13 +176,7 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
static int freezer_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
{
- rcu_read_lock();
- if (__cgroup_freezing_or_frozen(tsk)) {
- rcu_read_unlock();
- return -EBUSY;
- }
- rcu_read_unlock();
- return 0;
+ return cgroup_freezing(tsk) ? -EBUSY : 0;
}
static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
@@ -213,7 +206,7 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
/* Locking avoids race with FREEZING -> THAWED transitions. */
if (freezer->state == CGROUP_FREEZING)
- freeze_task(task, true);
+ freeze_task(task);
spin_unlock_irq(&freezer->lock);
}
@@ -231,7 +224,7 @@ static void update_if_frozen(struct cgroup *cgroup,
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
ntotal++;
- if (frozen(task))
+ if (freezing(task) && frozen(task))
nfrozen++;
}
@@ -279,10 +272,9 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
struct task_struct *task;
unsigned int num_cant_freeze_now = 0;
- freezer->state = CGROUP_FREEZING;
cgroup_iter_start(cgroup, &it);
while ((task = cgroup_iter_next(cgroup, &it))) {
- if (!freeze_task(task, true))
+ if (!freeze_task(task))
continue;
if (frozen(task))
continue;
@@ -300,12 +292,9 @@ static void unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
struct task_struct *task;
cgroup_iter_start(cgroup, &it);
- while ((task = cgroup_iter_next(cgroup, &it))) {
- thaw_process(task);
- }
+ while ((task = cgroup_iter_next(cgroup, &it)))
+ __thaw_task(task);
cgroup_iter_end(cgroup, &it);
-
- freezer->state = CGROUP_THAWED;
}
static int freezer_change_state(struct cgroup *cgroup,
@@ -319,20 +308,24 @@ static int freezer_change_state(struct cgroup *cgroup,
spin_lock_irq(&freezer->lock);
update_if_frozen(cgroup, freezer);
- if (goal_state == freezer->state)
- goto out;
switch (goal_state) {
case CGROUP_THAWED:
+ if (freezer->state != CGROUP_THAWED)
+ atomic_dec(&system_freezing_cnt);
+ freezer->state = CGROUP_THAWED;
unfreeze_cgroup(cgroup, freezer);
break;
case CGROUP_FROZEN:
+ if (freezer->state == CGROUP_THAWED)
+ atomic_inc(&system_freezing_cnt);
+ freezer->state = CGROUP_FREEZING;
retval = try_to_freeze_cgroup(cgroup, freezer);
break;
default:
BUG();
}
-out:
+
spin_unlock_irq(&freezer->lock);
return retval;
diff --git a/kernel/exit.c b/kernel/exit.c
index d0b7d98..95a4141 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -679,8 +679,6 @@ static void exit_mm(struct task_struct * tsk)
tsk->mm = NULL;
up_read(&mm->mmap_sem);
enter_lazy_tlb(mm, current);
- /* We don't want this task to be frozen prematurely */
- clear_freeze_flag(tsk);
task_unlock(tsk);
mm_update_next_owner(mm);
mmput(mm);
@@ -1040,6 +1038,7 @@ NORET_TYPE void do_exit(long code)
exit_rcu();
/* causes final put_task_struct in finish_task_switch(). */
tsk->state = TASK_DEAD;
+ tsk->flags |= PF_NOFREEZE; /* tell freezer to ignore us */
schedule();
BUG();
/* Avoid "noreturn function does return". */
diff --git a/kernel/fork.c b/kernel/fork.c
index da4a6a1..8278086 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -992,7 +992,6 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
new_flags |= PF_FORKNOEXEC;
new_flags |= PF_STARTING;
p->flags = new_flags;
- clear_freeze_flag(p);
}
SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
diff --git a/kernel/freezer.c b/kernel/freezer.c
index 7be56c5..9815b8d 100644
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -9,101 +9,114 @@
#include <linux/export.h>
#include <linux/syscalls.h>
#include <linux/freezer.h>
+#include <linux/kthread.h>
-/*
- * freezing is complete, mark current process as frozen
+/* total number of freezing conditions in effect */
+atomic_t system_freezing_cnt = ATOMIC_INIT(0);
+EXPORT_SYMBOL(system_freezing_cnt);
+
+/* indicate whether PM freezing is in effect, protected by pm_mutex */
+bool pm_freezing;
+bool pm_nosig_freezing;
+
+/* protects freezing and frozen transitions */
+static DEFINE_SPINLOCK(freezer_lock);
+
+/**
+ * freezing_slow_path - slow path for testing whether a task needs to be frozen
+ * @p: task to be tested
+ *
+ * This function is called by freezing() if system_freezing_cnt isn't zero
+ * and tests whether @p needs to enter and stay in frozen state. Can be
+ * called under any context. The freezers are responsible for ensuring the
+ * target tasks see the updated state.
*/
-static inline void frozen_process(void)
+bool freezing_slow_path(struct task_struct *p)
{
- if (!unlikely(current->flags & PF_NOFREEZE)) {
- current->flags |= PF_FROZEN;
- smp_wmb();
- }
- clear_freeze_flag(current);
+ if (p->flags & PF_NOFREEZE)
+ return false;
+
+ if (pm_nosig_freezing || cgroup_freezing(p))
+ return true;
+
+ if (pm_freezing && !(p->flags & PF_KTHREAD))
+ return true;
+
+ return false;
}
+EXPORT_SYMBOL(freezing_slow_path);
/* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(void)
+bool __refrigerator(bool check_kthr_stop)
{
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
- long save;
+ bool was_frozen = false;
+ long save = current->state;
- task_lock(current);
- if (freezing(current)) {
- frozen_process();
- task_unlock(current);
- } else {
- task_unlock(current);
- return;
- }
- save = current->state;
pr_debug("%s entered refrigerator\n", current->comm);
- spin_lock_irq(&current->sighand->siglock);
- recalc_sigpending(); /* We sent fake signal, clean it up */
- spin_unlock_irq(&current->sighand->siglock);
-
- /* prevent accounting of that task to load */
- current->flags |= PF_FREEZING;
-
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
- if (!frozen(current))
+
+ spin_lock_irq(&freezer_lock);
+ current->flags |= PF_FROZEN;
+ if (!freezing(current) ||
+ (check_kthr_stop && kthread_should_stop()))
+ current->flags &= ~PF_FROZEN;
+ spin_unlock_irq(&freezer_lock);
+
+ if (!(current->flags & PF_FROZEN))
break;
+ was_frozen = true;
schedule();
}
- /* Remove the accounting blocker */
- current->flags &= ~PF_FREEZING;
-
pr_debug("%s left refrigerator\n", current->comm);
- __set_current_state(save);
+
+ /*
+ * Restore saved task state before returning. The mb'd version
+ * needs to be used; otherwise, it might silently break
+ * synchronization which depends on ordered task state change.
+ */
+ set_current_state(save);
+
+ return was_frozen;
}
-EXPORT_SYMBOL(refrigerator);
+EXPORT_SYMBOL(__refrigerator);
static void fake_signal_wake_up(struct task_struct *p)
{
unsigned long flags;
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ if (lock_task_sighand(p, &flags)) {
+ signal_wake_up(p, 0);
+ unlock_task_sighand(p, &flags);
+ }
}
/**
- * freeze_task - send a freeze request to given task
- * @p: task to send the request to
- * @sig_only: if set, the request will only be sent if the task has the
- * PF_FREEZER_NOSIG flag unset
- * Return value: 'false', if @sig_only is set and the task has
- * PF_FREEZER_NOSIG set or the task is frozen, 'true', otherwise
+ * freeze_task - send a freeze request to given task
+ * @p: task to send the request to
+ *
+ * If @p is freezing, the freeze request is sent by setting %TIF_FREEZE
+ * flag and either sending a fake signal to it or waking it up, depending
+ * on whether it has %PF_FREEZER_NOSIG set.
*
- * The freeze request is sent by setting the tasks's TIF_FREEZE flag and
- * either sending a fake signal to it or waking it up, depending on whether
- * or not it has PF_FREEZER_NOSIG set. If @sig_only is set and the task
- * has PF_FREEZER_NOSIG set (ie. it is a typical kernel thread), its
- * TIF_FREEZE flag will not be set.
+ * RETURNS:
+ * %false, if @p is not freezing or already frozen; %true, otherwise
*/
-bool freeze_task(struct task_struct *p, bool sig_only)
+bool freeze_task(struct task_struct *p)
{
- /*
- * We first check if the task is freezing and next if it has already
- * been frozen to avoid the race with frozen_process() which first marks
- * the task as frozen and next clears its TIF_FREEZE.
- */
- if (!freezing(p)) {
- smp_rmb();
- if (frozen(p))
- return false;
-
- if (!sig_only || should_send_signal(p))
- set_freeze_flag(p);
- else
- return false;
+ unsigned long flags;
+
+ spin_lock_irqsave(&freezer_lock, flags);
+ if (!freezing(p) || frozen(p)) {
+ spin_unlock_irqrestore(&freezer_lock, flags);
+ return false;
}
- if (should_send_signal(p)) {
+ if (!(p->flags & PF_KTHREAD)) {
fake_signal_wake_up(p);
/*
* fake_signal_wake_up() goes through p's scheduler
@@ -111,56 +124,48 @@ bool freeze_task(struct task_struct *p, bool sig_only)
* TASK_RUNNING transition can't race with task state
* testing in try_to_freeze_tasks().
*/
- } else if (sig_only) {
- return false;
} else {
wake_up_state(p, TASK_INTERRUPTIBLE);
}
+ spin_unlock_irqrestore(&freezer_lock, flags);
return true;
}
-void cancel_freezing(struct task_struct *p)
+void __thaw_task(struct task_struct *p)
{
unsigned long flags;
- if (freezing(p)) {
- pr_debug(" clean up: %s\n", p->comm);
- clear_freeze_flag(p);
- spin_lock_irqsave(&p->sighand->siglock, flags);
- recalc_sigpending_and_wake(p);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- }
-}
-
-static int __thaw_process(struct task_struct *p)
-{
- if (frozen(p)) {
- p->flags &= ~PF_FROZEN;
- return 1;
- }
- clear_freeze_flag(p);
- return 0;
+ /*
+ * Clear freezing and kick @p if FROZEN. Clearing is guaranteed to
+ * be visible to @p as waking up implies wmb. Waking up inside
+ * freezer_lock also prevents wakeups from leaking outside
+ * refrigerator.
+ */
+ spin_lock_irqsave(&freezer_lock, flags);
+ if (frozen(p))
+ wake_up_process(p);
+ spin_unlock_irqrestore(&freezer_lock, flags);
}
-/*
- * Wake up a frozen process
+/**
+ * set_freezable - make %current freezable
*
- * task_lock() is needed to prevent the race with refrigerator() which may
- * occur if the freezing of tasks fails. Namely, without the lock, if the
- * freezing of tasks failed, thaw_tasks() might have run before a task in
- * refrigerator() could call frozen_process(), in which case the task would be
- * frozen and no one would thaw it.
+ * Mark %current freezable and enter refrigerator if necessary.
*/
-int thaw_process(struct task_struct *p)
+bool set_freezable(void)
{
- task_lock(p);
- if (__thaw_process(p) == 1) {
- task_unlock(p);
- wake_up_process(p);
- return 1;
- }
- task_unlock(p);
- return 0;
+ might_sleep();
+
+ /*
+ * Modify flags while holding freezer_lock. This ensures the
+ * freezer notices that we aren't frozen yet or the freezing
+ * condition is visible to try_to_freeze() below.
+ */
+ spin_lock_irq(&freezer_lock);
+ current->flags &= ~PF_NOFREEZE;
+ spin_unlock_irq(&freezer_lock);
+
+ return try_to_freeze();
}
-EXPORT_SYMBOL(thaw_process);
+EXPORT_SYMBOL(set_freezable);
diff --git a/kernel/kthread.c b/kernel/kthread.c
index b6d216a..3d3de633 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -59,6 +59,31 @@ int kthread_should_stop(void)
EXPORT_SYMBOL(kthread_should_stop);
/**
+ * kthread_freezable_should_stop - should this freezable kthread return now?
+ * @was_frozen: optional out parameter, indicates whether %current was frozen
+ *
+ * kthread_should_stop() for freezable kthreads, which will enter
+ * refrigerator if necessary. This function is safe from kthread_stop() /
+ * freezer deadlock and freezable kthreads should use this function instead
+ * of calling try_to_freeze() directly.
+ */
+bool kthread_freezable_should_stop(bool *was_frozen)
+{
+ bool frozen = false;
+
+ might_sleep();
+
+ if (unlikely(freezing(current)))
+ frozen = __refrigerator(true);
+
+ if (was_frozen)
+ *was_frozen = frozen;
+
+ return kthread_should_stop();
+}
+EXPORT_SYMBOL_GPL(kthread_freezable_should_stop);
+
+/**
* kthread_data - return data value specified on kthread creation
* @task: kthread task in question
*
@@ -257,7 +282,7 @@ int kthreadd(void *unused)
set_cpus_allowed_ptr(tsk, cpu_all_mask);
set_mems_allowed(node_states[N_HIGH_MEMORY]);
- current->flags |= PF_NOFREEZE | PF_FREEZER_NOSIG;
+ current->flags |= PF_NOFREEZE;
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 5314a94..605149a 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -590,17 +590,6 @@ static void power_down(void)
while(1);
}
-static int prepare_processes(void)
-{
- int error = 0;
-
- if (freeze_processes()) {
- error = -EBUSY;
- thaw_processes();
- }
- return error;
-}
-
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
@@ -633,7 +622,7 @@ int hibernate(void)
sys_sync();
printk("done.\n");
- error = prepare_processes();
+ error = freeze_processes();
if (error)
goto Finish;
@@ -796,7 +785,7 @@ static int software_resume(void)
}
pr_debug("PM: Preparing processes for restore.\n");
- error = prepare_processes();
+ error = freeze_processes();
if (error) {
swsusp_close(FMODE_READ);
goto Done;
diff --git a/kernel/power/process.c b/kernel/power/process.c
index addbbe5..77274c9 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -22,16 +22,7 @@
*/
#define TIMEOUT (20 * HZ)
-static inline int freezable(struct task_struct * p)
-{
- if ((p == current) ||
- (p->flags & PF_NOFREEZE) ||
- (p->exit_state != 0))
- return 0;
- return 1;
-}
-
-static int try_to_freeze_tasks(bool sig_only)
+static int try_to_freeze_tasks(bool user_only)
{
struct task_struct *g, *p;
unsigned long end_time;
@@ -46,17 +37,14 @@ static int try_to_freeze_tasks(bool sig_only)
end_time = jiffies + TIMEOUT;
- if (!sig_only)
+ if (!user_only)
freeze_workqueues_begin();
while (true) {
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (frozen(p) || !freezable(p))
- continue;
-
- if (!freeze_task(p, sig_only))
+ if (p == current || !freeze_task(p))
continue;
/*
@@ -77,7 +65,7 @@ static int try_to_freeze_tasks(bool sig_only)
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
- if (!sig_only) {
+ if (!user_only) {
wq_busy = freeze_workqueues_busy();
todo += wq_busy;
}
@@ -103,11 +91,6 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs = elapsed_csecs64;
if (todo) {
- /* This does not unfreeze processes that are already frozen
- * (we have slightly ugly calling convention in that respect,
- * and caller must call thaw_processes() if something fails),
- * but it cleans up leftover PF_FREEZE requests.
- */
printk("\n");
printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
"(%d tasks refusing to freeze, wq_busy=%d):\n",
@@ -115,15 +98,11 @@ static int try_to_freeze_tasks(bool sig_only)
elapsed_csecs / 100, elapsed_csecs % 100,
todo - wq_busy, wq_busy);
- thaw_workqueues();
-
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- task_lock(p);
- if (!wakeup && freezing(p) && !freezer_should_skip(p))
+ if (!wakeup && !freezer_should_skip(p) &&
+ p != current && freezing(p) && !frozen(p))
sched_show_task(p);
- cancel_freezing(p);
- task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
} else {
@@ -136,12 +115,18 @@ static int try_to_freeze_tasks(bool sig_only)
/**
* freeze_processes - Signal user space processes to enter the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_processes(void)
{
int error;
+ if (!pm_freezing)
+ atomic_inc(&system_freezing_cnt);
+
printk("Freezing user space processes ... ");
+ pm_freezing = true;
error = try_to_freeze_tasks(true);
if (!error) {
printk("done.");
@@ -150,17 +135,22 @@ int freeze_processes(void)
printk("\n");
BUG_ON(in_atomic());
+ if (error)
+ thaw_processes();
return error;
}
/**
* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and system is fully thawed.
*/
int freeze_kernel_threads(void)
{
int error;
printk("Freezing remaining freezable tasks ... ");
+ pm_nosig_freezing = true;
error = try_to_freeze_tasks(false);
if (!error)
printk("done.");
@@ -168,37 +158,32 @@ int freeze_kernel_threads(void)
printk("\n");
BUG_ON(in_atomic());
+ if (error)
+ thaw_processes();
return error;
}
-static void thaw_tasks(bool nosig_only)
+void thaw_processes(void)
{
struct task_struct *g, *p;
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (!freezable(p))
- continue;
+ if (pm_freezing)
+ atomic_dec(&system_freezing_cnt);
+ pm_freezing = false;
+ pm_nosig_freezing = false;
- if (nosig_only && should_send_signal(p))
- continue;
+ oom_killer_enable();
+
+ printk("Restarting tasks ... ");
- if (cgroup_freezing_or_frozen(p))
- continue;
+ thaw_workqueues();
- thaw_process(p);
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ __thaw_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
-}
-void thaw_processes(void)
-{
- oom_killer_enable();
-
- printk("Restarting tasks ... ");
- thaw_workqueues();
- thaw_tasks(true);
- thaw_tasks(false);
schedule();
printk("done.\n");
}
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4953dc0..d336b27 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -106,13 +106,11 @@ static int suspend_prepare(void)
goto Finish;
error = suspend_freeze_processes();
- if (error) {
- suspend_stats.failed_freeze++;
- dpm_save_failed_step(SUSPEND_FREEZE);
- } else
+ if (!error)
return 0;
- suspend_thaw_processes();
+ suspend_stats.failed_freeze++;
+ dpm_save_failed_step(SUSPEND_FREEZE);
usermodehelper_enable();
Finish:
pm_notifier_call_chain(PM_POST_SUSPEND);
diff --git a/kernel/power/user.c b/kernel/power/user.c
index e2aff0f..c202e2e 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -257,10 +257,8 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd,
break;
error = freeze_processes();
- if (error) {
- thaw_processes();
+ if (error)
usermodehelper_enable();
- }
if (!error)
data->frozen = 1;
break;
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