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Message-Id: <5CC26E7D020000F9000625E6@prv1-mh.provo.novell.com>
Date:   Thu, 25 Apr 2019 20:35:41 -0600
From:   "Gang He" <ghe@suse.com>
To:     <jlbec@evilplan.org>, <mark@fasheh.com>, <jiangqi903@gmail.com>
Cc:     <akpm@linux-foundation.org>, <ocfs2-devel@oss.oracle.com>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ocfs2: add last unlock times in locking_state
References: <20190425091250.3625-1-ghe@suse.com>
 <c855abce-d62c-5fe0-3b31-c252077b4530@gmail.com>
In-Reply-To: <c855abce-d62c-5fe0-3b31-c252077b4530@gmail.com>
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Hello Joseph,


>>> On 4/26/2019 at  9:21 am, in message
<c855abce-d62c-5fe0-3b31-c252077b4530@gmail.com>, Joseph Qi
<jiangqi903@gmail.com> wrote:
> Hi Gang,
> 
> On 19/4/25 17:12, Gang He wrote:
>> ocfs2 file system uses locking_state file under debugfs to dump
>> each ocfs2 file system's dlm lock resources, but the dlm lock
>> resources in memory are becoming more and more after the files
>> were touched by the user. it will become a bit difficult to analyze
>> these dlm lock resource records in locking_state file by the upper
>> scripts, though some files are not active for now, which were
>> accessed long time ago.
>> Then, I'd like to add last pr/ex unlock times in locking_state file
>> for each dlm lock resource record, the the upper scripts can use
>> last unlock time to filter inactive dlm lock resource record.
>> 
>> Signed-off-by: Gang He <ghe@suse.com>
>> ---
>>  fs/ocfs2/dlmglue.c | 21 +++++++++++++++++----
>>  fs/ocfs2/ocfs2.h   |  1 +
>>  2 files changed, 18 insertions(+), 4 deletions(-)
>> 
>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>> index af405586c5b1..dccf4136f8c1 100644
>> --- a/fs/ocfs2/dlmglue.c
>> +++ b/fs/ocfs2/dlmglue.c
>> @@ -448,7 +448,7 @@ static void ocfs2_update_lock_stats(struct 
> ocfs2_lock_res *res, int level,
>>  				    struct ocfs2_mask_waiter *mw, int ret)
>>  {
>>  	u32 usec;
>> -	ktime_t kt;
>> +	ktime_t last, kt;
>>  	struct ocfs2_lock_stats *stats;
>>  
>>  	if (level == LKM_PRMODE)
>> @@ -458,7 +458,8 @@ static void ocfs2_update_lock_stats(struct 
> ocfs2_lock_res *res, int level,
>>  	else
>>  		return;
>>  
>> -	kt = ktime_sub(ktime_get(), mw->mw_lock_start);
>> +	last = ktime_get();
>> +	kt = ktime_sub(last, mw->mw_lock_start);
>>  	usec = ktime_to_us(kt);
>>  
>>  	stats->ls_gets++;
>> @@ -474,6 +475,8 @@ static void ocfs2_update_lock_stats(struct 
> ocfs2_lock_res *res, int level,
>>  
>>  	if (ret)
>>  		stats->ls_fail++;
>> +
>> +	stats->ls_last = ktime_to_timespec(last).tv_sec;
>>  }
>>  
>>  static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
>> @@ -3093,8 +3096,10 @@ static void *ocfs2_dlm_seq_next(struct seq_file *m, 
> void *v, loff_t *pos)
>>   *	- Lock stats printed
>>   * New in version 3
>>   *	- Max time in lock stats is in usecs (instead of nsecs)
>> + * New in version 4
>> + *	- Add last pr/ex unlock times in secs
> 
> Why not usecs?
The time is the seconds from the system boot, just like uptime command.
I feel the user do not care more accurate time, secondly, the u32 type can keep more long time until it overflows.  

> BTW, should we change tools side like debugfs as well?
Theoretically, the format will affect the upper debugfs.ocfs2 tool, 
but, I quickly look at this part code of debugfs.ocfs2, this part code looks has been dead.
Anyway, I will look at this part carefully, if it still works, I will do the corresponding change.


Thanks
Gang 


> 
> Thanks,
> Joseph
> 
>>   */
>> -#define OCFS2_DLM_DEBUG_STR_VERSION 3
>> +#define OCFS2_DLM_DEBUG_STR_VERSION 4
>>  static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
>>  {
>>  	int i;
>> @@ -3145,6 +3150,8 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void 
> *v)
>>  # define lock_max_prmode(_l)		((_l)->l_lock_prmode.ls_max)
>>  # define lock_max_exmode(_l)		((_l)->l_lock_exmode.ls_max)
>>  # define lock_refresh(_l)		((_l)->l_lock_refresh)
>> +# define lock_last_prmode(_l)		((_l)->l_lock_prmode.ls_last)
>> +# define lock_last_exmode(_l)		((_l)->l_lock_exmode.ls_last)
>>  #else
>>  # define lock_num_prmode(_l)		(0)
>>  # define lock_num_exmode(_l)		(0)
>> @@ -3155,6 +3162,8 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void 
> *v)
>>  # define lock_max_prmode(_l)		(0)
>>  # define lock_max_exmode(_l)		(0)
>>  # define lock_refresh(_l)		(0)
>> +# define lock_last_prmode(_l)		(0)
>> +# define lock_last_exmode(_l)		(0)
>>  #endif
>>  	/* The following seq_print was added in version 2 of this output */
>>  	seq_printf(m, "%u\t"
>> @@ -3165,6 +3174,8 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void 
> *v)
>>  		   "%llu\t"
>>  		   "%u\t"
>>  		   "%u\t"
>> +		   "%u\t"
>> +		   "%u\t"
>>  		   "%u\t",
>>  		   lock_num_prmode(lockres),
>>  		   lock_num_exmode(lockres),
>> @@ -3174,7 +3185,9 @@ static int ocfs2_dlm_seq_show(struct seq_file *m, void 
> *v)
>>  		   lock_total_exmode(lockres),
>>  		   lock_max_prmode(lockres),
>>  		   lock_max_exmode(lockres),
>> -		   lock_refresh(lockres));
>> +		   lock_refresh(lockres),
>> +		   lock_last_prmode(lockres),
>> +		   lock_last_exmode(lockres));
>>  
>>  	/* End the line */
>>  	seq_printf(m, "\n");
>> diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
>> index 1f029fbe8b8d..8efa022684f4 100644
>> --- a/fs/ocfs2/ocfs2.h
>> +++ b/fs/ocfs2/ocfs2.h
>> @@ -164,6 +164,7 @@ struct ocfs2_lock_stats {
>>  
>>  	/* Storing max wait in usecs saves 24 bytes per inode */
>>  	u32		ls_max;		/* Max wait in USEC */
>> +	u32		ls_last;	/* Last unlock time in SEC */
>>  };
>>  #endif
>>  
>>