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Questions tagged [lttng]

A set of userspace and kernel tracing tools for the Linux operating system.

A set of userspace and kernel tracing tools for the Linux operating system.

https://lttng.org/

92 questions
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1 answer

Consuming LTTng events in a .NET Core app

I've got a .NET Core application that I would like to set up to listen to LTTng events, but I've found little to no documentation anywhere on how to actually do this in code, in C# / .NET Core. I've read a good deal about how even the CoreCLR team…
teeth
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2 answers

Linux Trace Tool lttng on Raspbian: Kernel tracer not available

I have installed lttng on my Raspbian running on a Raspberry Pi 3 Model B+. I get the following error when following a first demo from the website (as root): # lttng create my-kernel-session --output=/tmp/my-kernel-trace Spawning a session…
Bart Meyers
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1 answer

Wrong timestamps in lttng

I'm trying to use lttng to analyse the scheduling on a remote system. However, displaying the trace as text format with babeltrace shows that all recorded events have the same timestamp. Consequently, the visualization in TraceCompass…
Thomas McGuire
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1 answer

Linux scheduler: sched_wakeup on an active task

I am trying to trace the Linux scheduler using Lttng by tracing the events sched_wakeup and sched_switch in the 4.4 kernel (Ubuntu 16.04 LTS). Sometimes I get the sched_wakeup event even before the thread has switched out. I don't understand the…
Cupo
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Kernel trace using Lttng

I have been playing around with linux trace tools (Lttng, http://lttng.org/) for sometime now. Currently, I'm interpreting the trace using Eclipse with Lttng plug-in. Although using this tool I could retrieve logs associated with system calls,…
shark1608
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LTTng/Perf: Difference between events used for exiting (sched_process_exit) and freeing (sched_process_free) a process

Currently, I'm getting into the topic of kernel tracing with LTTng and Perf. I'm especially interested to trace the different states a process is in. I stumbled over the event sched_process_free and sched_process_exit. I'm wondering if my current…
juergen_p
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What is the state of system level tracing in production Linux systems (RH/CentOS and Debian/Ubuntu)?

I'm helping develop an internal cloud infrastructure (OpenStack) to provide our departments with a fully on-premises alternative to AWS/Rackspace/SoftLayer/etc. My boss just relayed a question to me from some internal customer who is asking us to…
Jim Dennis
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API analysis aborted in Eclipse due to incomplete build path

I am attempting to build the lttng portion of linuxtools by source. I downloaded and extracted the linuxtools-2.0.0 tarball. I imported the lttng subfolder to my workspace. This consisted of 28 separate…
msteppe91
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3 answers

How do I build and deploy LTTng to an embedded Linux system?

The README files in the source tarballs available on http://lttng.org/download seem to assume that one is building on the same Linux system that will be the target for traces. I've found other resources that explain how to do this (the LTTng Project…
Daryl Spitzer
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1 answer

Cloning Babeltrace events from generator for random-access traversal

I'm trying to check for a certain chain of events in an LTTNG event log using Babeltrace 1. The LTTNG log is loaded using a Babeltrace collection: import babeltrace my_collection =…
Some programmer dude
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Getting no GCallocationTick stack counts when running .NET binary with COMPlus_EnableEventLog=1

Background I want to monitor for my ASP.NET Core 2.1 application which methods do the most allocation, and for this I wanted to use the LTTng events along with some other tools to help out. I have essentially tried following this guide:…
kqr
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Is it possible to use babeltrace Python API (or any other software tool) for reading “live” LTTng traces?

I am using LTTng to trace an application. To read the LTTng trace data I am using Python API babeltrace. I switch-on the LTTng tracing and the trace data is stored in a folder. I use Python API babeltrace to read the recorded traced data. Now, is it…
NewToCoding
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lttng: Unable to list kernel events: Kernel tracer not available

Currently running a CENTOS 7 machine trying to install lttng-tools and lttng-modules. I am going through the steps required to get lttng setup on my machine located at http://lttng.org/docs/v2.9/ and am experiencing issues with just about every…
dadrexel
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Insert tracepoint statements automatically in C++ using liblttng

I am working with a user-space C++ application and using the Linux trace tool kit, which provides tracepoints (provider, name, etc.). I want to place in my source code a - tracepoint(provider, name, ...) statement at every function entry and exit…
Source Code
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Can I query LTTNG if a given tracepoint with given args is going to be traced, before tracing it?

We need to adapt a huge number of existing traces, printf-like, to LTTNG. One of the issues we are foreseeing is that we will need a catch-all tracepoint with the format of args plus a char* string. We are trying to find a way to avoid having to…
mustang51
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