Merge branch 'pm-sleep'

* pm-sleep:
  PM / Freezer: Remove references to TIF_FREEZE in comments
  PM / Sleep: Add more wakeup source initialization routines
  PM / Hibernate: Enable usermodehelpers in hibernate() error path
  PM / Sleep: Make __pm_stay_awake() delete wakeup source timers
  PM / Sleep: Fix race conditions related to wakeup source timer function
  PM / Sleep: Fix possible infinite loop during wakeup source destruction
  PM / Hibernate: print physical addresses consistently with other parts of kernel
  PM: Add comment describing relationships between PM callbacks to pm.h
  PM / Sleep: Drop suspend_stats_update()
  PM / Sleep: Make enter_state() in kernel/power/suspend.c static
  PM / Sleep: Unify kerneldoc comments in kernel/power/suspend.c
  PM / Sleep: Remove unnecessary label from suspend_freeze_processes()
  PM / Sleep: Do not check wakeup too often in try_to_freeze_tasks()
  PM / Sleep: Initialize wakeup source locks in wakeup_source_add()
  PM / Hibernate: Refactor and simplify freezer_test_done
  PM / Hibernate: Thaw kernel threads in hibernation_snapshot() in error/test path
  PM / Freezer / Docs: Document the beauty of freeze/thaw semantics
  PM / Suspend: Avoid code duplication in suspend statistics update
  PM / Sleep: Introduce generic callbacks for new device PM phases
  PM / Sleep: Introduce "late suspend" and "early resume" of devices

1 files changed, 12 insertions, 12 deletions

diff --git a/kernel/power/process.c b/kernel/power/process.c
index 7e426459e60..0d2aeb22610 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -53,11 +53,9 @@ static int try_to_freeze_tasks(bool user_only)
                          * It is "frozen enough".  If the task does wake
                          * up, it will immediately call try_to_freeze.
                          *
-                         * Because freeze_task() goes through p's
-                         * scheduler lock after setting TIF_FREEZE, it's
-                         * guaranteed that either we see TASK_RUNNING or
-                         * try_to_stop() after schedule() in ptrace/signal
-                         * stop sees TIF_FREEZE.
+                         * Because freeze_task() goes through p's scheduler lock, it's
+                         * guaranteed that TASK_STOPPED/TRACED -> TASK_RUNNING
+                         * transition can't race with task state testing here.
                          */
                         if (!task_is_stopped_or_traced(p) &&
                             !freezer_should_skip(p))
@@ -98,13 +96,15 @@ static int try_to_freeze_tasks(bool user_only)
                        elapsed_csecs / 100, elapsed_csecs % 100,
                        todo - wq_busy, wq_busy);
 
-                read_lock(&tasklist_lock);
-                do_each_thread(g, p) {
-                        if (!wakeup && !freezer_should_skip(p) &&
-                            p != current && freezing(p) && !frozen(p))
-                                sched_show_task(p);
-                } while_each_thread(g, p);
-                read_unlock(&tasklist_lock);
+                if (!wakeup) {
+                        read_lock(&tasklist_lock);
+                        do_each_thread(g, p) {
+                                if (p != current && !freezer_should_skip(p)
+                                    && freezing(p) && !frozen(p))
+                                        sched_show_task(p);
+                        } while_each_thread(g, p);
+                        read_unlock(&tasklist_lock);
+                }
         } else {
                 printk("(elapsed %d.%02d seconds) ", elapsed_csecs / 100,
                         elapsed_csecs % 100);