Merge branch 'linus' into cont_syslog

[safe/jmp/linux-2.6] / kernel / softlockup.c

diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index d225790..4b493f6 100644 (file)
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -25,6 +25,7 @@ static DEFINE_SPINLOCK(print_lock);
 static DEFINE_PER_CPU(unsigned long, softlockup_touch_ts); /* touch timestamp */
 static DEFINE_PER_CPU(unsigned long, softlockup_print_ts); /* print timestamp */
 static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog);
+static DEFINE_PER_CPU(bool, softlock_touch_sync);
 
 static int __read_mostly did_panic;
 int __read_mostly softlockup_thresh = 60;
@@ -79,6 +80,12 @@ void touch_softlockup_watchdog(void)
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
+void touch_softlockup_watchdog_sync(void)
+{
+       __raw_get_cpu_var(softlock_touch_sync) = true;
+       __raw_get_cpu_var(softlockup_touch_ts) = 0;
+}
+
 void touch_all_softlockup_watchdogs(void)
 {
        int cpu;
@@ -118,6 +125,14 @@ void softlockup_tick(void)
        }
 
        if (touch_ts == 0) {
+               if (unlikely(per_cpu(softlock_touch_sync, this_cpu))) {
+                       /*
+                        * If the time stamp was touched atomically
+                        * make sure the scheduler tick is up to date.
+                        */
+                       per_cpu(softlock_touch_sync, this_cpu) = false;
+                       sched_clock_tick();
+               }
                __touch_softlockup_watchdog();
                return;
        }
@@ -140,11 +155,11 @@ void softlockup_tick(void)
         * Wake up the high-prio watchdog task twice per
         * threshold timespan.
         */
-       if (now > touch_ts + softlockup_thresh/2)
+       if (time_after(now - softlockup_thresh/2, touch_ts))
                wake_up_process(per_cpu(softlockup_watchdog, this_cpu));
 
        /* Warn about unreasonable delays: */
-       if (now <= (touch_ts + softlockup_thresh))
+       if (time_before_eq(now - softlockup_thresh, touch_ts))
                return;
 
        per_cpu(softlockup_print_ts, this_cpu) = touch_ts;