[lttng-dev] Fwd: LTTng user space data not flushed out

Yannick Lamarre ylamarre at efficios.com
Thu Mar 28 12:44:06 EDT 2019

Hi TSK, 
>From [1]: 

You must provide the following items for the bug to be reproducible: 

    * Component(s) involved : [ https://bugs.lttng.org/projects/lttng-tools | LTTng-tools ] , [ https://bugs.lttng.org/projects/lttng-ust | LTTng-UST ] , [ https://bugs.lttng.org/projects/lttng-modules | LTTng-modules ] , [ https://bugs.lttng.org/projects/urcu | liburcu ] , or [ https://bugs.lttng.org/projects/babeltrace | Babeltrace ] ? If the bug involves more than one component, report it under the [ https://bugs.lttng.org/projects/lttng | Redmine LTTng umbrella project ] . 
    * Component version : Full version of the software exhibiting the bug ( --version option) or Git commit hash for custom builds. 
    * System information : 
        * Architecture, number of CPUs. 
        * Operating system version ( uname -a ) and distribution 

Please explicitly report the version of each components: lttng-tools, lttng-ust, lttng-modules, liburcu, and babeltrace. 
[1] https://lttng.org/community/#bug-reporting-guidelines 

From: "tujalasaikiran" <tujalasaikiran at gmail.com> 
To: "lttng-dev" <lttng-dev at lists.lttng.org> 
Sent: Thursday, March 28, 2019 7:50:17 AM 
Subject: [lttng-dev] Fwd: LTTng user space data not flushed out 

---------- Forwarded message ---------- 
From: Jérémie Galarneau < [ mailto:jeremie.galarneau at efficios.com | jeremie.galarneau at efficios.com ] > 
Date: Monday, March 25, 2019 
Subject: LTTng user space data not flushed out 
To: tujalasaikiran < [ mailto:tujalasaikiran at gmail.com | tujalasaikiran at gmail.com ] > 

Hi Tujala, 

Please use the public development mailing list 
( [ mailto:lttng-dev at lists.lttng.org | lttng-dev at lists.lttng.org ] ) to get community support. 
Private support is available through EfficiOS' support agreements. 


On Sat, 23 Mar 2019 at 13:13, tujalasaikiran < [ mailto:tujalasaikiran at gmail.com | tujalasaikiran at gmail.com ] > wrote: 
> Hi, 
> I'm using LTTng live mode, the "live" parameter in the below command is the time at which data is flushed. We get zero content size packets if we don't have any data generated from the tracer. This is true for kernel space domain, that is getting content size zero packets. Whereas in the user space domain, I'm not getting zero content size packets this makes the "live viewer" (babeltrace) to not to show any trace data until the session stop. 
> My application generates the kernel domain events frequently whereas userspace domain events generate very rarely. Default flush time in "lttng create" command is 1 second, this is honored in kernel domain whereas in userspace domain not. 
> Below commands, I'm using for LTTng configuration and using babel trace viewer to view live trace. 
> lttng create mysession --live 
> lttng enable-event -k sched_swich 
> lttng enable-event -u mytrace_point:tp_one 
> lttng start 
> babeltrace --input-format=lttng-live net://localhost/host/mypc-name/mysession 
> <---- not getting any data from babeltrace until I stop the session------> 
> lttng stop 
> <--- I'm getting data from babeltrace once I stop the lttng session ---> 
> lttng destroy 
> Thanks, 
> TSK. 

Jérémie Galarneau 
EfficiOS Inc. 
[ http://www.efficios.com/ | http://www.efficios.com ] 

lttng-dev mailing list 
lttng-dev at lists.lttng.org 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.lttng.org/pipermail/lttng-dev/attachments/20190328/bc54f8d7/attachment.html>

More information about the lttng-dev mailing list