softlockup: Stop spurious softlockup messages due to overflow
Ensure additions on touch_ts do not overflow. This can occur
when the top 32 bits of the TSC reach 0xffffffff causing
additions to touch_ts to overflow and this in turn generates
spurious softlockup warnings.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1268994482.1798.6.camel@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/softlockup.c b/kernel/softlockup.c
index 0d4c789..4b493f6 100644
--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -155,11 +155,11 @@
* 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;