From: Hongchao Zhang <hongchao.zhang@intel.com>
Date: Wed, 10 May 2017 03:45:19 +0000 (+0800)
Subject: LU-9235 libcfs: don't dump stack if just touched
X-Git-Tag: 2.10.52~18
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=1376094062c1e46c985f04d82821114d84329699

LU-9235 libcfs: don't dump stack if just touched

If some lc_watchdog was touched before lcw_dump_stack dumped
the stack of the thread, it should not dump it anymore for
the thread is verified to be active and no need to dump.

Change-Id: I8e4acc1793bb8458ee3b6dc73f2953670ed22896
Signed-off-by: Hongchao Zhang <hongchao.zhang@intel.com>
Reviewed-on: https://review.whamcloud.com/23162
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/libcfs/libcfs/watchdog.c b/libcfs/libcfs/watchdog.c
index 401210c..359ca94 100644
--- a/libcfs/libcfs/watchdog.c
+++ b/libcfs/libcfs/watchdog.c
@@ -160,6 +160,11 @@ static void lcw_dump_stack(struct lc_watchdog *lcw)
 
 	timediff = ktime_to_timespec64(ktime_sub(ktime_get(),
 				       lcw->lcw_last_touched));
+
+	/* LU-9235: Don't dump stack if the thread is just touched. */
+	if (timediff.tv_sec == 0)
+		return;
+
 	/*
 	 * Check to see if we should throttle the watchdog timer to avoid
 	 * too many dumps going to the console thus triggering an NMI.