Hi,

On Sunday, 19 November 2006 03:04, Pavel Machek wrote:
> Hi!
> 
> > 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 <[EMAIL PROTECTED]>
> > ---
> >  include/linux/freezer.h |    6 -----
> >  kernel/power/process.c  |   55 
> > +++++++++++++++++++++++++++---------------------
> >  2 files changed, 33 insertions(+), 28 deletions(-)
> > 
> > Index: linux-2.6.19-rc5-mm2/include/linux/freezer.h
> > ===================================================================
> > --- linux-2.6.19-rc5-mm2.orig/include/linux/freezer.h
> > +++ linux-2.6.19-rc5-mm2/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
> >  
> >  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)
> >  {
> > Index: linux-2.6.19-rc5-mm2/kernel/power/process.c
> > ===================================================================
> > --- linux-2.6.19-rc5-mm2.orig/kernel/power/process.c
> > +++ linux-2.6.19-rc5-mm2/kernel/power/process.c
> > @@ -20,6 +20,8 @@
> >   */
> >  #define TIMEOUT    (20 * HZ)
> >  
> > +#define FREEZER_KERNEL_THREADS 0
> > +#define FREEZER_USER_SPACE 1
> 
> The variable is named "is_user_space"... so maybe the defines are not
> strictly needed?

Not strlctly, but if I see

        thaw_tasks(FREEZER_KERNEL_THREADS);
        thaw_tasks(FREEZER_USER_SPACE);

I can figure out what's going on even without looking at thaw_tasks().

> > +   do_each_thread(g, p) {
> > +           if (!freezeable(p))
> > +                   continue;
> >  
> > +           if (is_user_space(p)) {
> > +                   if (!thaw_user_space)
> > +                           continue;
> > +           } else {
> > +                   if (thaw_user_space)
> > +                           continue;
> > +           }
> 
> if (is_user_space(p) != thaw_user_space)
>       continue;

Ah, good idea.  In fact I prefer if (is_user_space(p) == !thaw_user_space),
because it will work even if thaw_user_space is different to 1 and 0.

Revised patch follows.

---
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 <[EMAIL PROTECTED]>
---
 include/linux/freezer.h |    6 -----
 kernel/power/process.c  |   53 ++++++++++++++++++++++++++----------------------
 2 files changed, 30 insertions(+), 29 deletions(-)

Index: linux-2.6.19-rc5-mm2/include/linux/freezer.h
===================================================================
--- linux-2.6.19-rc5-mm2.orig/include/linux/freezer.h
+++ linux-2.6.19-rc5-mm2/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
 
 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)
 {
Index: linux-2.6.19-rc5-mm2/kernel/power/process.c
===================================================================
--- linux-2.6.19-rc5-mm2.orig/kernel/power/process.c
+++ linux-2.6.19-rc5-mm2/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_
        }
 }
 
+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);
-
-               pass++;
-       } while (pass < 2 && all);
-
+       do_each_thread(g, p) {
+               if (!freezeable(p))
+                       continue;
+
+               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");
 }

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to