[PATCH] pm: fix process freezing
authorPavel Machek <pavel@ucw.cz>
Sat, 3 Sep 2005 22:57:05 +0000 (15:57 -0700)
committerLinus Torvalds <torvalds@evo.osdl.org>
Mon, 5 Sep 2005 07:06:17 +0000 (00:06 -0700)
If process freezing fails, some processes are frozen, and rest are left in
"were asked to be frozen" state.  Thats wrong, we should leave it in some
consistent state.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kernel/power/process.c

index f7da5bfc914e36904c4585278d1bb50aa8008724..28de118f7a0b047c6c507a8adbf2113ce52bb21d 100644 (file)
@@ -81,13 +81,33 @@ int freeze_processes(void)
                } while_each_thread(g, p);
                read_unlock(&tasklist_lock);
                yield();                        /* Yield is okay here */
-               if (time_after(jiffies, start_time + TIMEOUT)) {
+               if (todo && time_after(jiffies, start_time + TIMEOUT)) {
                        printk( "\n" );
                        printk(KERN_ERR " stopping tasks failed (%d tasks remaining)\n", todo );
-                       return todo;
+                       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) {
+               read_lock(&tasklist_lock);
+               do_each_thread(g, p)
+                       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;