PM / Sleep: Do not check wakeup too often in try_to_freeze_tasks()

Use the observation that it is more efficient to check the wakeup
variable once before the loop reporting tasks that were not
frozen in try_to_freeze_tasks() than to do that in every step of that
loop.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

1 files changed, 9 insertions, 7 deletions

diff --git a/kernel/power/process.c b/kernel/power/process.c
index 7e426459e60a..6aeb5efe00eb 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -98,13 +98,15 @@ 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);