[Ocfs2-devel] [PATCH v2 RESEND] ocfs2: add uuid to ocfs2 thread name for problem analysis

[Joseph Qi <joseph.qi@huawei.com>]

Hi Gang,
You worry won't exist. kthread_create will take care of it.

Thanks,
Joseph

On 2015/11/2 10:47, Gang He wrote:
> Hello Joseph,
> 
> It make sense to make the thread name unique, here are some comments inline. 
> 
> 
>>>>
>> A node can mount multiple ocfs2 volumes. And if thread names are same
>> for each volume/domain, it will bring inconvenience when analyzing
>> problems because we have to identify which volume/domain the messages
>> belong to.
>> Since thread name will be printed to messages, so add volume uuid or dlm
>> name to thread name can benefit problem analysis.
>>
>> Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
>> ---
>>  fs/ocfs2/dlm/dlmdomain.c   | 4 +++-
>>  fs/ocfs2/dlm/dlmrecovery.c | 2 +-
>>  fs/ocfs2/dlm/dlmthread.c   | 3 ++-
>>  fs/ocfs2/dlmglue.c         | 3 ++-
>>  fs/ocfs2/journal.c         | 4 ++--
>>  5 files changed, 10 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c 
>> index 7df88a6..cc794b5 100644
>> --- a/fs/ocfs2/dlm/dlmdomain.c
>> +++ b/fs/ocfs2/dlm/dlmdomain.c
>> @@ -1860,6 +1860,7 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
>>  	int status;
>>  	unsigned int backoff;
>>  	unsigned int total_backoff = 0;
>> +	char wq_name[O2NM_MAX_NAME_LEN];
>>
>>  	BUG_ON(!dlm);
>>
>> @@ -1889,7 +1890,8 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
>>  		goto bail;
>>  	}
>>
>> -	dlm->dlm_worker = create_singlethread_workqueue("dlm_wq");
>> +	snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
> If the dm->name is too length, the wq_name will be filled fully without the trailing '\0', then pass the wq_name to  create_singlethread_workqueue is OK?
> Maybe the code looks like,
> 	snprintf(wq_name, O2NM_MAX_NAME_LEN, "dlm_wq-%s", dlm->name);
> 	wq_name[O2NM_MAX_NAME_LEN - 1] = '\0';
> 
>> +	dlm->dlm_worker = create_singlethread_workqueue(wq_name);
>>  	if (!dlm->dlm_worker) {
>>  		status = -ENOMEM;
>>  		mlog_errno(status);
>> diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
>> index a43f9ef..8caf881 100644
>> --- a/fs/ocfs2/dlm/dlmrecovery.c
>> +++ b/fs/ocfs2/dlm/dlmrecovery.c
>> @@ -205,7 +205,7 @@ int dlm_launch_recovery_thread(struct dlm_ctxt *dlm)
>>  	mlog(0, "starting dlm recovery thread...\n");
>>
>>  	dlm->dlm_reco_thread_task = kthread_run(dlm_recovery_thread, dlm,
>> -						"dlm_reco_thread");
>> +			"dlm_reco-%s", dlm->name);
>>  	if (IS_ERR(dlm->dlm_reco_thread_task)) {
>>  		mlog_errno(PTR_ERR(dlm->dlm_reco_thread_task));
>>  		dlm->dlm_reco_thread_task = NULL;
>> diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
>> index 69aac6f..a1b6c34 100644
>> --- a/fs/ocfs2/dlm/dlmthread.c
>> +++ b/fs/ocfs2/dlm/dlmthread.c
>> @@ -483,7 +483,8 @@ int dlm_launch_thread(struct dlm_ctxt *dlm)
>>  {
>>  	mlog(0, "Starting dlm_thread...\n");
>>
>> -	dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm_thread");
>> +	dlm->dlm_thread_task = kthread_run(dlm_thread, dlm, "dlm-%s",
>> +			dlm->name);
>>  	if (IS_ERR(dlm->dlm_thread_task)) {
>>  		mlog_errno(PTR_ERR(dlm->dlm_thread_task));
>>  		dlm->dlm_thread_task = NULL;
>> diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
>> index 23157e4..fd4f536 100644
>> --- a/fs/ocfs2/dlmglue.c
>> +++ b/fs/ocfs2/dlmglue.c
>> @@ -2998,7 +2998,8 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
>>  	}
>>
>>  	/* launch downconvert thread */
>> -	osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc");
>> +	osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s",
> uuid_str looks a little long, e.g. 27F06FE897C742D1B2FD435D477B458E, 
> If use th full string to pack a thread name, the name looks too long, I just suggestion to use the first 6 characters.
> The first 6 characters should be unique in a machine, will not be conflicted between a few ocfs2 mountings.
>  
>> +			osb->uuid_str);
>>  	if (IS_ERR(osb->dc_task)) {
>>  		status = PTR_ERR(osb->dc_task);
>>  		osb->dc_task = NULL;
>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>> index 627d88c..86b9a93 100644
>> --- a/fs/ocfs2/journal.c
>> +++ b/fs/ocfs2/journal.c
>> @@ -1074,7 +1074,7 @@ int ocfs2_journal_load(struct ocfs2_journal *journal, 
>> int local, int replayed)
>>  	/* Launch the commit thread */
>>  	if (!local) {
>>  		osb->commit_task = kthread_run(ocfs2_commit_thread, osb,
>> -					       "ocfs2cmt");
>> +				"ocfs2cmt-%s", osb->uuid_str);
>>  		if (IS_ERR(osb->commit_task)) {
>>  			status = PTR_ERR(osb->commit_task);
>>  			osb->commit_task = NULL;
>> @@ -1491,7 +1491,7 @@ void ocfs2_recovery_thread(struct ocfs2_super *osb, int 
>> node_num)
>>  		goto out;
>>
>>  	osb->recovery_thread_task =  kthread_run(__ocfs2_recovery_thread, osb,
>> -						 "ocfs2rec");
>> +			"ocfs2rec-%s", osb->uuid_str);
>>  	if (IS_ERR(osb->recovery_thread_task)) {
>>  		mlog_errno((int)PTR_ERR(osb->recovery_thread_task));
>>  		osb->recovery_thread_task = NULL;
>> -- 
>> 1.8.4.3
>>
>>
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>> Ocfs2-devel at oss.oracle.com 
>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
> 
> .
>