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

[David Goulet]

Incoming patch.

Cheers
David

On 10-09-09 12:40 PM, Mathieu Desnoyers wrote:
> * 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
>>
>

-- 
David Goulet
LTTng project, DORSAL Lab.

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