[ltt-dev] Kernel and User Space tracers have different timestamp reference

[florent boudet]

Hi!

Thank you for your answers, I will keep posted for new releases.
By the way, LTTng and UST are awesome tools, thank you for the hard work!

Florent

On Fri, Nov 26, 2010 at 2:47 PM, David Goulet <david.goulet at polymtl.ca> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> Yes,
>
> And also, the UST patch is done and ready for merge :)
>
> Very soon guys!
>
> David
>
> On 10-11-26 08:32 AM, Mathieu Desnoyers wrote:
>> Hi!
>>
>> Yesterday evening, Julien and I were actively finishing the vDSO work
>> that is needed to have synchronized timestamps between the kernel LTTng
>> and UST on x86. It should be ready very soon. Keep posted for a new
>> release. :)
>>
>> By the way, in the initial implementation, only 64-bit processes on
>> 64-bit x86 systems with synchronized TSCs will benefit from the vDSO
>> speed. All other x86 setups will fallback on a system call, which will
>> still work, albeit being a bit slower.
>>
>> Thanks,
>>
>> Mathieu
>>
>> * Alexandre Montplaisir (alexandre.montplaisir at polymtl.ca) wrote:
>>> Hi folks,
>>>
>>> I've received this bug report about kernel/UST trace synchronization.
>>> Anyone knows what's the status on this?
>>>
>>> Thanks,
>>> Alexandre
>>>
>>>
>>> On 10-11-26 03:24 AM, Florent Boudet wrote:
>>>> Hello,
>>>>
>>>> I am sorry to contact you directly instead of filling a bug, but it
>>>> seems the option is disabled on the launchpad project...
>>>>
>>>> I have recorded userspace traces at the same time as kernel traces, and
>>>> opened both with LTTv.
>>>> Timestamp for userspace traces and timestamp for kernel traces have
>>>> different origins, which make it difficult to analyze.
>>>> I am not sure about the cause, this might be related to a GMT/localtime
>>>> issue...
>>>>
>>>> Regards,
>>>> Florent Boudet
>>>
>>>
>>> _______________________________________________
>>> ltt-dev mailing list
>>> ltt-dev at lists.casi.polymtl.ca
>>> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>>>
>>
>
> - --
> David Goulet
> LTTng project, DORSAL Lab.
>
> 1024D/16BD8563
> BE3C 672B 9331 9796 291A  14C6 4AF7 C14B 16BD 8563
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.10 (GNU/Linux)
>
> iEYEARECAAYFAkzvunoACgkQSvfBSxa9hWP1gQCfTTq08bZsAX5kZd9aL98gTUPJ
> 1bsAnRJ2LzczcavguNjeADa5WrtN1MoW
> =jWhQ
> -----END PGP SIGNATURE-----
>