[tip:perf/core] watchdog: Add comments to explain the watchdog_disabled variable

From: tip-bot for anish kumar
Date: Mon Mar 18 2013 - 07:02:11 EST


Commit-ID: b66a2356d7108a15b8b5c9b8e6213e05ead22cd6
Gitweb: http://git.kernel.org/tip/b66a2356d7108a15b8b5c9b8e6213e05ead22cd6
Author: anish kumar <anish198519851985@xxxxxxxxx>
AuthorDate: Tue, 12 Mar 2013 14:44:08 -0400
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 14 Mar 2013 08:24:05 +0100

watchdog: Add comments to explain the watchdog_disabled variable

The watchdog_disabled flag is a bit cryptic. However it's
usefulness is multifold. Uses are:

1. Check if smpboot_register_percpu_thread function passed.

2. Makes sure that user enables and disables the watchdog in
sequence i.e. enable watchdog->disable watchdog->enable watchdog
Unlike enable watchdog->enable watchdog which is wrong.

Signed-off-by: anish kumar <anish198519851985@xxxxxxxxx>
[small text cleanups]
Signed-off-by: Don Zickus <dzickus@xxxxxxxxxx>
Cc: chuansheng.liu@xxxxxxxxx
Cc: paulmck@xxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1363113848-18344-1-git-send-email-dzickus@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/watchdog.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 4a94467..05039e3 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -517,6 +517,11 @@ int proc_dowatchdog(struct ctl_table *table, int write,
return ret;

set_sample_period();
+ /*
+ * Watchdog threads shouldn't be enabled if they are
+ * disabled. The 'watchdog_disabled' variable check in
+ * watchdog_*_all_cpus() function takes care of this.
+ */
if (watchdog_enabled && watchdog_thresh)
watchdog_enable_all_cpus();
else
--
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