#undef DEBUG
-#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
static inline int freezeable(struct task_struct * p)
{
- if ((p == current) ||
+ if ((p == current) ||
(p->flags & PF_NOFREEZE) ||
- (p->exit_state == EXIT_ZOMBIE) ||
- (p->exit_state == EXIT_DEAD) ||
- (p->state == TASK_STOPPED))
+ (p->exit_state != 0))
return 0;
return 1;
}
+/*
+ * freezing is complete, mark current process as frozen
+ */
+static inline void frozen_process(void)
+{
+ if (!unlikely(current->flags & PF_NOFREEZE)) {
+ current->flags |= PF_FROZEN;
+ wmb();
+ }
+ clear_freeze_flag(current);
+}
+
/* Refrigerator is place where frozen processes are stored :-). */
void refrigerator(void)
{
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
long save;
+
+ 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);
- frozen_process(current);
spin_lock_irq(¤t->sighand->siglock);
recalc_sigpending(); /* We sent fake signal, clean it up */
spin_unlock_irq(¤t->sighand->siglock);
- while (frozen(current)) {
- current->state = TASK_UNINTERRUPTIBLE;
+ for (;;) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ if (!frozen(current))
+ break;
schedule();
}
pr_debug("%s left refrigerator\n", current->comm);
- current->state = save;
+ __set_current_state(save);
}
-static inline void freeze_process(struct task_struct *p)
+static void freeze_task(struct task_struct *p)
{
unsigned long flags;
if (!freezing(p)) {
- freeze(p);
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ rmb();
+ if (!frozen(p)) {
+ set_freeze_flag(p);
+ if (p->state == TASK_STOPPED)
+ force_sig_specific(SIGSTOP, p);
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ signal_wake_up(p, p->state == TASK_STOPPED);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
}
}
if (freezing(p)) {
pr_debug(" clean up: %s\n", p->comm);
- do_not_freeze(p);
+ clear_freeze_flag(p);
spin_lock_irqsave(&p->sighand->siglock, flags);
- recalc_sigpending_tsk(p);
+ recalc_sigpending_and_wake(p);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
}
-static inline int is_user_space(struct task_struct *p)
-{
- return p->mm && !(p->flags & PF_BORROWED_MM);
-}
-
-static unsigned int try_to_freeze_tasks(int freeze_user_space)
+static int try_to_freeze_tasks(int freeze_user_space)
{
struct task_struct *g, *p;
unsigned long end_time;
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (!freezeable(p))
- continue;
-
- if (frozen(p))
+ if (frozen(p) || !freezeable(p))
continue;
- if (p->state == TASK_TRACED &&
- (frozen(p->parent) ||
- p->parent->state == TASK_STOPPED)) {
- cancel_freezing(p);
- continue;
- }
- if (is_user_space(p)) {
- if (!freeze_user_space)
+ if (freeze_user_space) {
+ if (p->state == TASK_TRACED &&
+ frozen(p->parent)) {
+ cancel_freezing(p);
continue;
-
- /* Freeze the task unless there is a vfork
- * completion pending
+ }
+ /*
+ * Kernel threads should not have TIF_FREEZE set
+ * at this point, so we must ensure that either
+ * p->mm is not NULL *and* PF_BORROWED_MM is
+ * unset, or TIF_FRREZE is left unset.
+ * The task_lock() is necessary to prevent races
+ * with exit_mm() or use_mm()/unuse_mm() from
+ * occuring.
*/
- if (!p->vfork_done)
- freeze_process(p);
- } else {
- if (freeze_user_space)
+ task_lock(p);
+ if (!p->mm || (p->flags & PF_BORROWED_MM)) {
+ task_unlock(p);
continue;
-
- freeze_process(p);
+ }
+ freeze_task(p);
+ task_unlock(p);
+ } else {
+ freeze_task(p);
}
- todo++;
+ if (!freezer_should_skip(p))
+ todo++;
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
yield(); /* Yield is okay here */
* but it cleans up leftover PF_FREEZE requests.
*/
printk("\n");
- printk(KERN_ERR "Stopping %s timed out after %d seconds "
+ printk(KERN_ERR "Freezing of %s timed out after %d seconds "
"(%d tasks refusing to freeze):\n",
- freeze_user_space ? "user space processes" :
- "kernel threads",
+ freeze_user_space ? "user space " : "tasks ",
TIMEOUT / HZ, todo);
+ show_state();
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (is_user_space(p) == !freeze_user_space)
- continue;
-
- if (freezeable(p) && !frozen(p))
+ task_lock(p);
+ if (freezing(p) && !freezer_should_skip(p))
printk(KERN_ERR " %s\n", p->comm);
-
cancel_freezing(p);
+ task_unlock(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
}
- return todo;
+ return todo ? -EBUSY : 0;
}
/**
* freeze_processes - tell processes to enter the refrigerator
- *
- * Returns 0 on success, or the number of processes that didn't freeze,
- * although they were told to.
*/
int freeze_processes(void)
{
- unsigned int nr_unfrozen;
+ int error;
printk("Stopping tasks ... ");
- nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
- if (nr_unfrozen)
- return nr_unfrozen;
+ error = try_to_freeze_tasks(FREEZER_USER_SPACE);
+ if (error)
+ return error;
sys_sync();
- nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
- if (nr_unfrozen)
- return nr_unfrozen;
+ error = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
+ if (error)
+ return error;
printk("done.\n");
BUG_ON(in_atomic());
if (!freezeable(p))
continue;
- if (is_user_space(p) == !thaw_user_space)
+ if (!p->mm == thaw_user_space)
continue;
- if (!thaw_process(p))
- printk(KERN_WARNING " Strange, %s not stopped\n",
- p->comm );
+ thaw_process(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
}
projects / linux-2.6-omap-h63xx.git / blobdiff