From 6c83b4818dd65eb17e633b6b629a81da7bed90b3 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 11 Feb 2012 00:00:34 +0100 Subject: 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 --- kernel/power/process.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'kernel/power/process.c') 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); -- cgit v1.2.3 From 37f08be11be9a7d9351fb1b9b408259519a126f3 Mon Sep 17 00:00:00 2001 From: Marcos Paulo de Souza Date: Tue, 21 Feb 2012 23:57:47 +0100 Subject: PM / Freezer: Remove references to TIF_FREEZE in comments This patch removes all the references in the code about the TIF_FREEZE flag removed by commit a3201227f803ad7fd43180c5195dbe5a2bf998aa freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE There still are some references to TIF_FREEZE in Documentation/power/freezing-of-tasks.txt, but it looks like that documentation needs more thorough work to reflect how the new freezer works, and hence merely removing the references to TIF_FREEZE won't really help. So I have not touched that part in this patch. Suggested-by: Srivatsa S. Bhat Signed-off-by: Marcos Paulo de Souza Signed-off-by: Rafael J. Wysocki --- kernel/power/process.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) (limited to 'kernel/power/process.c') diff --git a/kernel/power/process.c b/kernel/power/process.c index 6aeb5efe00eb..0d2aeb226108 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)) -- cgit v1.2.3