flush_workqueue(): use preempt_disable to hold off cpu hotplug

[powerpc.git] / kernel / power / process.c

diff --git a/kernel/power/process.c b/kernel/power/process.c
index fd0ebb9..0884193 100644 (file)
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -8,7 +8,6 @@
 
 #undef DEBUG
 
-#include <linux/smp_lock.h>
 #include <linux/interrupt.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
@@ -25,11 +24,9 @@
 
 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;
 }
@@ -48,8 +45,10 @@ void refrigerator(void)
        recalc_sigpending(); /* We sent fake signal, clean it up */
        spin_unlock_irq(&current->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);
@@ -61,10 +60,16 @@ static inline void freeze_process(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)) {
+                       if (p->state == TASK_STOPPED)
+                               force_sig_specific(SIGSTOP, p);
+
+                       freeze(p);
+                       spin_lock_irqsave(&p->sighand->siglock, flags);
+                       signal_wake_up(p, p->state == TASK_STOPPED);
+                       spin_unlock_irqrestore(&p->sighand->siglock, flags);
+               }
        }
 }
 
@@ -86,76 +91,98 @@ static inline int is_user_space(struct task_struct *p)
        return p->mm && !(p->flags & PF_BORROWED_MM);
 }
 
-/* 0 = success, else # of processes that we failed to stop */
-int freeze_processes(void)
+static unsigned int try_to_freeze_tasks(int freeze_user_space)
 {
-       int todo, nr_user, user_frozen;
-       unsigned long start_time;
        struct task_struct *g, *p;
+       unsigned long end_time;
+       unsigned int todo;
 
-       printk("Stopping tasks... ");
-       start_time = jiffies;
-       user_frozen = 0;
+       end_time = jiffies + TIMEOUT;
        do {
-               nr_user = todo = 0;
+               todo = 0;
                read_lock(&tasklist_lock);
                do_each_thread(g, p) {
                        if (!freezeable(p))
                                continue;
+
                        if (frozen(p))
                                continue;
-                       if (p->state == TASK_TRACED &&
-                           (frozen(p->parent) ||
-                            p->parent->state == TASK_STOPPED)) {
+
+                       if (p->state == TASK_TRACED && frozen(p->parent)) {
                                cancel_freezing(p);
                                continue;
                        }
                        if (is_user_space(p)) {
+                               if (!freeze_user_space)
+                                       continue;
+
                                /* Freeze the task unless there is a vfork
                                 * completion pending
                                 */
                                if (!p->vfork_done)
                                        freeze_process(p);
-                               nr_user++;
                        } else {
-                               /* Freeze only if the user space is frozen */
-                               if (user_frozen)
-                                       freeze_process(p);
-                               todo++;
+                               if (freeze_user_space)
+                                       continue;
+
+                               freeze_process(p);
                        }
+                       todo++;
                } while_each_thread(g, p);
                read_unlock(&tasklist_lock);
-               todo += nr_user;
-               if (!user_frozen && !nr_user) {
-                       sys_sync();
-                       start_time = jiffies;
-               }
-               user_frozen = !nr_user;
                yield();                        /* Yield is okay here */
-               if (todo && time_after(jiffies, start_time + TIMEOUT))
+               if (todo && time_after(jiffies, end_time))
                        break;
-       } while(todo);
+       } while (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.
-        */
        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 "Stopping tasks timed out "
-                       "after %d seconds (%d tasks remaining):\n",
-                       TIMEOUT / HZ, todo);
+               printk(KERN_ERR "Stopping %s timed out after %d seconds "
+                               "(%d tasks refusing to freeze):\n",
+                               freeze_user_space ? "user space processes" :
+                                       "kernel threads",
+                               TIMEOUT / HZ, todo);
                read_lock(&tasklist_lock);
                do_each_thread(g, p) {
+                       if (is_user_space(p) == !freeze_user_space)
+                               continue;
+
                        if (freezeable(p) && !frozen(p))
                                printk(KERN_ERR " %s\n", p->comm);
+
                        cancel_freezing(p);
                } while_each_thread(g, p);
                read_unlock(&tasklist_lock);
-               return todo;
        }
 
+       return todo;
+}
+
+/**
+ *     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;
+
+       printk("Stopping tasks ... ");
+       nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
+       if (nr_unfrozen)
+               return nr_unfrozen;
+
+       sys_sync();
+       nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
+       if (nr_unfrozen)
+               return nr_unfrozen;
+
        printk("done.\n");
        BUG_ON(in_atomic());
        return 0;