[ltt-dev] (forw) [chris.meyers.fsu@gmail.com: Re: ltt channel thread safe?]

[compudj@krystal.dyndns.org (Mathieu Desnoyers)]

* Pierre-Marc Fournier (pierre-marc.fournier at polymtl.ca) wrote:
> On 08/27/2010 01:01 PM, Mathieu Desnoyers wrote:
>> * Fu Juntang(David) (juntang.fu at windriver.com) wrote:
>>> Hi,Mathieu:
>>>    has the issue any update?
>>>
>>>    please see my test case and the trace logs(in the attachment), from
>>>   the trace log,we can see we can only see the trace datas from cpu_0:
>>>    ust.myevent: 18161.506516049
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 2 }
>>> ust.myevent: 18163.506594856
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 3 }
>>> ust.myevent: 18165.506667869
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 5 }
>>> ust.myevent: 18167.506735881
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 7 }
>>> ust.myevent: 18169.506818732
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 8 }
>>> ust.myevent: 18171.506903062
>>> (/home/Large_Space/Part_B/LogStore/LTTngLog_wrlinux-4.0/UST/UST_Logs/multi-thread/david-desktop-20100811163524864824113/11520_5504068123890634635/ust_0), 0, 0, , , 0, 0x0, MODE_UNKNOWN { firstthread = 10 }
>>> End trace set
>>>
>>>   we missed the trace logs:
>>>   trace_mark(ust, myevent, "secondthread %d", number);
>>
>> Oh, you created two events with same channel and same name, but with a
>> different first parameter name. This should be forbidden. UST should
>> take care of checking for these duplicate markers with non-matching
>> parameters.
>>
>> libust marker.c is checking for this, as it should:
>>
>> static int set_marker(struct marker_entry *entry, struct marker *elem,
>>                  int active)
>> {
>>          int ret = 0;
>>          WARN_ON(strcmp(entry->name, elem->name) != 0);
>>
>>          if (entry->format) {
>>                  if (strcmp(entry->format, elem->format) != 0) {
>> 			DBG("Format mismatch for probe %s (%s), marker (%s)",
>>                                  entry->name,
>>                                  entry->format,
>>                                  elem->format);
>>                          return -EPERM;
>>                  }
>>          } else {
>>
>> Pierre-Marc, why it this only showing the warning if UST_DEBUG is
>> defined ? This should always spit out the warning.
>>
>
> Agreed, it should probably be a WARN or ERR.

Nils/David, do you want to make a patch for this ?

pmf, I guess handing me a commit access might be handy.

Thanks!

Mathieu

>
> pmf
>

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com