Re: broken suspend (sched related) [Was: 2.6.24-rc4-mm1]

Jiri Slaby
2007-12-08T17:34:37Z

On 12/08/2007 04:24 PM, Ingo Molnar wrote:
> i'm wondering why it had no effect now - the new code is in essence a
> NOP over what we had. Could you send me your current (modified)
> kernel/softlockup.c code?

Only these changes:
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index e50b44a..7011549 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -25,7 +25,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp);
static DEFINE_PER_CPU(struct task_struct *, watchdog_task);

static int did_panic;
-int softlockup_thresh = 60;
+int softlockup_thresh = 10;

static int
softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
@@ -101,7 +101,11 @@ void softlockup_tick(void)

now = get_timestamp(this_cpu);

- /* Warn about unreasonable delays: */
+ /* Wake up the high-prio watchdog task every second: */
+ if (now > (touch_timestamp + 1))
+ wake_up_process(per_cpu(watchdog_task, this_cpu));
+
+ /* Warn about unreasonable 10+ seconds delays: */
if (now <= (touch_timestamp + softlockup_thresh))
return;

@@ -213,8 +217,9 @@ static int watchdog(void *__bind_cpu)
* debug-printout triggers in softlockup_tick().
*/
while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
touch_softlockup_watchdog();
- msleep_interruptible(10000);
+ schedule();

/*
* Only do the hung-tasks check on one CPU: