[PATCH] swsusp: Untangle thaw_processes

Move the loop from thaw_processes() to a separate function and call it
independently for kernel threads and user space processes so that the order
of thawing tasks is clearly visible.

Drop thaw_kernel_threads() which is never used.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 28 insertions, 27 deletions

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 294ebea859c9..6e05e3e7ce39 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -1,8 +1,5 @@
 /* Freezer declarations */
 
-#define FREEZER_KERNEL_THREADS 0
-#define FREEZER_ALL_THREADS 1
-
 #ifdef CONFIG_PM
 /*
  * Check if a process has been frozen
@@ -60,8 +57,7 @@ static inline void frozen_process(struct task_struct *p)
 
 extern void refrigerator(void);
 extern int freeze_processes(void);
-#define thaw_processes() do { thaw_some_processes(FREEZER_ALL_THREADS); } while(0)
-#define thaw_kernel_threads() do { thaw_some_processes(FREEZER_KERNEL_THREADS); } while(0)
+extern void thaw_processes(void);
 
 static inline int try_to_freeze(void)
 {
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 1badb9a89ade..fd0ebb942f50 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -20,6 +20,8 @@
  */
 #define TIMEOUT (20 * HZ)
 
+#define FREEZER_KERNEL_THREADS 0
+#define FREEZER_USER_SPACE 1
 
 static inline int freezeable(struct task_struct * p)
 {
@@ -79,6 +81,11 @@ static void cancel_freezing(struct task_struct *p)
         }
 }
 
+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)
 {
@@ -103,10 +110,9 @@ int freeze_processes(void)
                                 cancel_freezing(p);
                                 continue;
                         }
-                        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 (is_user_space(p)) {
+                                /* Freeze the task unless there is a vfork
+                                 * completion pending
                                  */
                                 if (!p->vfork_done)
                                         freeze_process(p);
@@ -155,31 +161,30 @@ int freeze_processes(void)
         return 0;
 }
 
-void thaw_some_processes(int all)
+static void thaw_tasks(int thaw_user_space)
 {
         struct task_struct *g, *p;
-        int pass = 0; /* Pass 0 = Kernel space, 1 = Userspace */
 
-        printk("Restarting tasks... ");
         read_lock(&tasklist_lock);
-        do {
-                do_each_thread(g, p) {
-                        /*
-                         * is_user = 0 if kernel thread or borrowed mm,
-                         * 1 otherwise.
-                         */
-                        int is_user = !!(p->mm && !(p->flags & PF_BORROWED_MM));
-                        if (!freezeable(p) || (is_user != pass))
-                                continue;
-                        if (!thaw_process(p))
-                                printk(KERN_INFO
-                                        "Strange, %s not stopped\n", p->comm);
-                } while_each_thread(g, p);
+        do_each_thread(g, p) {
+                if (!freezeable(p))
+                        continue;
 
-                pass++;
-        } while (pass < 2 && all);
+                if (is_user_space(p) == !thaw_user_space)
+                        continue;
 
+                if (!thaw_process(p))
+                        printk(KERN_WARNING " Strange, %s not stopped\n",
+                                p->comm );
+        } while_each_thread(g, p);
         read_unlock(&tasklist_lock);
+}
+
+void thaw_processes(void)
+{
+        printk("Restarting tasks ... ");
+        thaw_tasks(FREEZER_KERNEL_THREADS);
+        thaw_tasks(FREEZER_USER_SPACE);
         schedule();
         printk("done.\n");
 }