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Message-Id: <5CEB785F020000F900068371@prv1-mh.provo.novell.com>
Date:   Sun, 26 May 2019 23:40:47 -0600
From:   "Gang He" <ghe@suse.com>
To:     "Wengang" <wen.gang.wang@oracle.com>
Cc:     <jlbec@evilplan.org>, <mark@fasheh.com>, <jiangqi903@gmail.com>,
        <ocfs2-devel@oss.oracle.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [Ocfs2-devel] [PATCH V3 2/2] ocfs2: add locking filter
 debugfs file
References: <20190523104047.14794-1-ghe@suse.com>
 <20190523104047.14794-2-ghe@suse.com>
 <da93442d-3333-5bd6-ce0a-edb66a58109d@oracle.com>
 <5CE753AB020000F900067E5D@prv1-mh.provo.novell.com>
 <bcdefc65-7173-8911-3ba1-197b064b5fa5@oracle.com>
In-Reply-To: <bcdefc65-7173-8911-3ba1-197b064b5fa5@oracle.com>
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Hello Wengang,

Another patch will do the thing you mentioned.
The patch link is here, https://marc.info/?l=ocfs2-devel&m=155860816602506&w=2

Thanks
Gang


>>> On 2019/5/25 at 3:52, in message
<bcdefc65-7173-8911-3ba1-197b064b5fa5@oracle.com>, Wengang Wang
<wen.gang.wang@oracle.com> wrote:
> Hi Gang,
> 
> OK, I was thinking you are dumping the new last access time field too.
> 
> thanks,
> wengang
> 
> On 2019/5/23 19:15, Gang He wrote:
>> Hello Wengang,
>>
>> This patch is used to add a filter attribute(the default value is 0), the 
> kernel module can use this attribute value to filter the lock resources 
> dumping.
>> By default(the value is 0), the kernel module does not filter any lock 
> resources dumping, the behavior is like before.
>> If the user set a value(N) of this attribute, the kernel module will only 
> dump the latest N seconds active lock resources, this will avoid dumping lots 
> of inactive lock resources.
>>
>> Thanks
>> Gang
>>
>>>>> On 2019/5/24 at 0:43, in message
>> <da93442d-3333-5bd6-ce0a-edb66a58109d@oracle.com>, Wengang
>> <wen.gang.wang@oracle.com> wrote:
>>> Hi Gang,
>>>
>>> Could you paste an example of outputs before patch VS that after patch?
>>> I think that would directly show what the patch does.
>>>
>>> thanks,
>>> wengang
>>>
>>> On 05/23/2019 03:40 AM, Gang He wrote:
>>>> Add locking filter debugfs file, which is used to filter lock
>>>> resources dump from locking_state debugfs file.
>>>> We use d_filter_secs field to filter lock resources dump,
>>>> the default d_filter_secs(0) value filters nothing,
>>>> otherwise, only dump the last N seconds active lock resources.
>>>> This enhancement can avoid dumping lots of old records.
>>>> The d_filter_secs value can be changed via locking_filter file.
>>>>
>>>> Compared with v2, ocfs2_dlm_init_debug() returns directly with
>>>> error when creating locking filter debugfs file is failed, since
>>>> ocfs2_dlm_shutdown_debug() will handle this failure perfectly.
>>>> Compared with v1, the main change is to add CONFIG_OCFS2_FS_STATS
>>>> macro definition judgment.
>>>>
>>>> Signed-off-by: Gang He <ghe@suse.com>
>>>> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>>>> ---
>>>>    fs/ocfs2/dlmglue.c | 36 ++++++++++++++++++++++++++++++++++++
>>>>    fs/ocfs2/ocfs2.h   |  2 ++
>>>>    2 files changed, 38 insertions(+)
>>>>
>>>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>>>> index dccf4136f8c1..fbe4562cf4fe 100644
>>>> --- a/fs/ocfs2/dlmglue.c
>>>> +++ b/fs/ocfs2/dlmglue.c
>>>> @@ -3006,6 +3006,8 @@ struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
>>>>    	kref_init(&dlm_debug->d_refcnt);
>>>>    	INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
>>>>    	dlm_debug->d_locking_state = NULL;
>>>> +	dlm_debug->d_locking_filter = NULL;
>>>> +	dlm_debug->d_filter_secs = 0;
>>>>    out:
>>>>    	return dlm_debug;
>>>>    }
>>>> @@ -3104,11 +3106,33 @@ static int ocfs2_dlm_seq_show(struct seq_file *m,
>>> void *v)
>>>>    {
>>>>    	int i;
>>>>    	char *lvb;
>>>> +	u32 now, last = 0;
>>>>    	struct ocfs2_lock_res *lockres = v;
>>>> +	struct ocfs2_dlm_debug *dlm_debug =
>>>> +			((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug;
>>>>    
>>>>    	if (!lockres)
>>>>    		return -EINVAL;
>>>>    
>>>> +	if (dlm_debug->d_filter_secs) {
>>>> +		now = ktime_to_timespec(ktime_get()).tv_sec;
>>>> +#ifdef CONFIG_OCFS2_FS_STATS
>>>> +		if (lockres->l_lock_prmode.ls_last >
>>>> +		    lockres->l_lock_exmode.ls_last)
>>>> +			last = lockres->l_lock_prmode.ls_last;
>>>> +		else
>>>> +			last = lockres->l_lock_exmode.ls_last;
>>>> +#endif
>>>> +		/*
>>>> +		 * Use d_filter_secs field to filter lock resources dump,
>>>> +		 * the default d_filter_secs(0) value filters nothing,
>>>> +		 * otherwise, only dump the last N seconds active lock
>>>> +		 * resources.
>>>> +		 */
>>>> +		if ((now - last) > dlm_debug->d_filter_secs)
>>>> +			return 0;
>>>> +	}
>>>> +
>>>>    	seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
>>>>    
>>>>    	if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
>>>> @@ -3258,6 +3282,17 @@ static int ocfs2_dlm_init_debug(struct ocfs2_super
>>> *osb)
>>>>    		goto out;
>>>>    	}
>>>>    
>>>> +	dlm_debug->d_locking_filter = debugfs_create_u32("locking_filter",
>>>> +						0600,
>>>> +						osb->osb_debug_root,
>>>> +						&dlm_debug->d_filter_secs);
>>>> +	if (!dlm_debug->d_locking_filter) {
>>>> +		ret = -EINVAL;
>>>> +		mlog(ML_ERROR,
>>>> +		     "Unable to create locking filter debugfs file.\n");
>>>> +		goto out;
>>>> +	}
>>>> +
>>>>    	ocfs2_get_dlm_debug(dlm_debug);
>>>>    out:
>>>>    	return ret;
>>>> @@ -3269,6 +3304,7 @@ static void ocfs2_dlm_shutdown_debug(struct
>>> ocfs2_super *osb)
>>>>    
>>>>    	if (dlm_debug) {
>>>>    		debugfs_remove(dlm_debug->d_locking_state);
>>>> +		debugfs_remove(dlm_debug->d_locking_filter);
>>>>    		ocfs2_put_dlm_debug(dlm_debug);
>>>>    	}
>>>>    }
>>>> diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
>>>> index 8efa022684f4..f4da51099889 100644
>>>> --- a/fs/ocfs2/ocfs2.h
>>>> +++ b/fs/ocfs2/ocfs2.h
>>>> @@ -237,6 +237,8 @@ struct ocfs2_orphan_scan {
>>>>    struct ocfs2_dlm_debug {
>>>>    	struct kref d_refcnt;
>>>>    	struct dentry *d_locking_state;
>>>> +	struct dentry *d_locking_filter;
>>>> +	u32 d_filter_secs;
>>>>    	struct list_head d_lockres_tracking;
>>>>    };
>>>>