2012-10-04 13:49:06

by Prarit Bhargava

Subject: [PATCH] ntp, add debugfs entries for time_status and time_state

Add debugfs entries for ntp time_status and time_state. These are useful
for debugging ntp issues.

Signed-off-by: Prarit Bhargava <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Thomas Gleixner <[email protected]>
---
kernel/time/ntp.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 24174b4..e1ba393 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -15,6 +15,7 @@
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/debugfs.h>

#include "tick-internal.h"

@@ -965,3 +966,42 @@ void __init ntp_init(void)
{
ntp_clear();
}
+
+static int time_status_get(void *data, u64 *val)
+{
+ *val = time_status;
+ return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(time_status_fops, time_status_get, NULL, "0x%0llx\n");
+
+static int time_state_get(void *data, u64 *val)
+{
+ *val = time_state;
+ return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(time_state_fops, time_state_get, NULL, "0x%llx\n");
+
+static int __init ntp_debugfs_init(void)
+{
+ struct dentry *ntp_dentry, *time_status_dentry, *time_state_dentry;
+
+ ntp_dentry = debugfs_create_dir("ntp", NULL);
+ if (!ntp_dentry)
+ return -ENOMEM;
+
+ time_status_dentry = debugfs_create_file("time_status", 0444,
+ ntp_dentry, NULL,
+ &time_status_fops);
+ if (!time_status_dentry)
+ return -ENOMEM;
+
+ time_state_dentry = debugfs_create_file("time_state", 0444,
+ ntp_dentry, NULL,
+ &time_state_fops);
+ if (!time_state_dentry)
+ return -ENOMEM;
+
+ return 0;
+}
+/* debugfs init is core_initcall */
+postcore_initcall(ntp_debugfs_init);
--
1.7.9.3

2012-10-09 01:48:10

by john stultz

Subject: Re: [PATCH] ntp, add debugfs entries for time_status and time_state

On 10/04/2012 06:48 AM, Prarit Bhargava wrote:
> Add debugfs entries for ntp time_status and time_state. These are useful
> for debugging ntp issues.
Aren't these easily fetched from adjtimex()? How does having them in
debugfs help?

thanks
-john

2012-10-09 11:07:51

by Prarit Bhargava

Subject: Re: [PATCH] ntp, add debugfs entries for time_status and time_state

On 10/08/2012 09:47 PM, John Stultz wrote:
> On 10/04/2012 06:48 AM, Prarit Bhargava wrote:
>> Add debugfs entries for ntp time_status and time_state. These are useful
>> for debugging ntp issues.
> Aren't these easily fetched from adjtimex()? How does having them in debugfs help?
>

They are, however, there have been circumstances in the past when I've been
monitoring things from kernel-side that I've found it useful to have them in
debugfs.

P.

> thanks
> -john
>