From: John Stultz <john.stultz@linaro.org>
Date: Fri, 23 Mar 2012 02:14:46 +0000 (-0700)
Subject: time: Avoid scary backtraces when warning of > 11% adj
X-Git-Tag: accepted/tizen/common/20141203.182822~4968^2~7
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e919cfd42da54d400e7e0385f22cae3672dcf874;p=platform%2Fkernel%2Flinux-arm64.git

time: Avoid scary backtraces when warning of > 11% adj

Folks have been getting a number of warnings about time
adjustments > 11%. The WARN_ON leaves a big useless backtrace
so this patch removes it for a printk_once().

I'm still working to narrow down the cause of the > 11% adjustment.

Signed-off-by: John Stultz <john.stultz@linaro.org>
---

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 5d76e09..16a175b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -869,13 +869,15 @@ static void timekeeping_adjust(s64 offset)
 	} else /* No adjustment needed */
 		return;
 
-	WARN_ONCE(timekeeper.clock->maxadj &&
-			(timekeeper.mult + adj > timekeeper.clock->mult +
-						timekeeper.clock->maxadj),
-			"Adjusting %s more then 11%% (%ld vs %ld)\n",
+	if (unlikely(timekeeper.clock->maxadj &&
+			(timekeeper.mult + adj >
+			timekeeper.clock->mult + timekeeper.clock->maxadj))) {
+		printk_once(KERN_WARNING
+			"Adjusting %s more than 11%% (%ld vs %ld)\n",
 			timekeeper.clock->name, (long)timekeeper.mult + adj,
 			(long)timekeeper.clock->mult +
 				timekeeper.clock->maxadj);
+	}
 	/*
 	 * So the following can be confusing.
 	 *