[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>

diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 294ebea..6e05e3e 100644 (file)
--- 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 1badb9a..fd0ebb9 100644 (file)
--- 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");
 }