Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / kernel / power / process.c

diff --git a/kernel/power/process.c b/kernel/power/process.c
index 78d92dc..b2a5f67 100644 (file)
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -12,11 +12,12 @@
 #include <linux/interrupt.h>
 #include <linux/suspend.h>
 #include <linux/module.h>
+#include <linux/syscalls.h>
 
 /* 
  * Timeout for stopping processes
  */
-#define TIMEOUT        (6 * HZ)
+#define TIMEOUT        (20 * HZ)
 
 
 static inline int freezeable(struct task_struct * p)
@@ -25,73 +26,118 @@ static inline int freezeable(struct task_struct * p)
            (p->flags & PF_NOFREEZE) ||
            (p->exit_state == EXIT_ZOMBIE) ||
            (p->exit_state == EXIT_DEAD) ||
-           (p->state == TASK_STOPPED) ||
-           (p->state == TASK_TRACED))
+           (p->state == TASK_STOPPED))
                return 0;
        return 1;
 }
 
 /* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(unsigned long flag)
+void refrigerator(void)
 {
        /* Hmm, should we be allowed to suspend when there are realtime
           processes around? */
        long save;
        save = current->state;
-       current->state = TASK_UNINTERRUPTIBLE;
        pr_debug("%s entered refrigerator\n", current->comm);
        printk("=");
-       current->flags &= ~PF_FREEZE;
 
+       frozen_process(current);
        spin_lock_irq(&current->sighand->siglock);
        recalc_sigpending(); /* We sent fake signal, clean it up */
        spin_unlock_irq(&current->sighand->siglock);
 
-       current->flags |= PF_FROZEN;
-       while (current->flags & PF_FROZEN)
+       while (frozen(current)) {
+               current->state = TASK_UNINTERRUPTIBLE;
                schedule();
+       }
        pr_debug("%s left refrigerator\n", current->comm);
        current->state = save;
 }
 
+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);
+       }
+}
+
 /* 0 = success, else # of processes that we failed to stop */
 int freeze_processes(void)
 {
-       int todo;
-       unsigned long start_time;
+       int todo, nr_user, user_frozen;
+       unsigned long start_time;
        struct task_struct *g, *p;
-       
+       unsigned long flags;
+
        printk( "Stopping tasks: " );
        start_time = jiffies;
+       user_frozen = 0;
        do {
-               todo = 0;
+               nr_user = todo = 0;
                read_lock(&tasklist_lock);
                do_each_thread(g, p) {
-                       unsigned long flags;
                        if (!freezeable(p))
                                continue;
-                       if ((p->flags & PF_FROZEN) ||
-                           (p->state == TASK_TRACED) ||
-                           (p->state == TASK_STOPPED))
+                       if (frozen(p))
                                continue;
-
-                       /* FIXME: smp problem here: we may not access other process' flags
-                          without locking */
-                       p->flags |= PF_FREEZE;
-                       spin_lock_irqsave(&p->sighand->siglock, flags);
-                       signal_wake_up(p, 0);
-                       spin_unlock_irqrestore(&p->sighand->siglock, flags);
-                       todo++;
+                       if (p->mm && !(p->flags & PF_BORROWED_MM)) {
+                               /* The task is a user-space one.
+                                * Freeze it unless there's 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++;
+                       }
                } while_each_thread(g, p);
                read_unlock(&tasklist_lock);
-               yield();                        /* Yield is okay here */
-               if (time_after(jiffies, start_time + TIMEOUT)) {
-                       printk( "\n" );
-                       printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
-                       return todo;
+               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))
+                       break;
        } 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) {
+               printk( "\n" );
+               printk(KERN_ERR " stopping tasks timed out "
+                       "after %d seconds (%d tasks remaining):\n",
+                       TIMEOUT / HZ, todo);
+               read_lock(&tasklist_lock);
+               do_each_thread(g, p) {
+                       if (freezeable(p) && !frozen(p))
+                               printk(KERN_ERR "  %s\n", p->comm);
+                       if (freezing(p)) {
+                               pr_debug("  clean up: %s\n", p->comm);
+                               p->flags &= ~PF_FREEZE;
+                               spin_lock_irqsave(&p->sighand->siglock, flags);
+                               recalc_sigpending_tsk(p);
+                               spin_unlock_irqrestore(&p->sighand->siglock, flags);
+                       }
+               } while_each_thread(g, p);
+               read_unlock(&tasklist_lock);
+               return todo;
+       }
+
        printk( "|\n" );
        BUG_ON(in_atomic());
        return 0;
@@ -106,10 +152,7 @@ void thaw_processes(void)
        do_each_thread(g, p) {
                if (!freezeable(p))
                        continue;
-               if (p->flags & PF_FROZEN) {
-                       p->flags &= ~PF_FROZEN;
-                       wake_up_process(p);
-               } else
+               if (!thaw_process(p))
                        printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
        } while_each_thread(g, p);