ftrace

I'm using ftrace on Android on a couple of different devices, but I noticed that the output format differs between them. In some cases, the TGID of the current process is included, while in others, it is not. The TGID is very useful in the current application I'm using ftrace on, and I'm wondering how I could enable that. I'm aware of the sysfs file "/sys/kernel/debug/tracing/options/print-tgid", but this isn't available on my devices, unfortunately. Are there any kernel options or ftrace handles that can be used to add TGID to the ftrace output format? # _-----=> irqs-off # / _----=> need

I have installed Ftrace on android AVD and try to use Ftrace's functionality, but it does not work. Below is a list of what I did: Install ubuntu 10.04 LTS Install essential tools such as android sdk, toolchain, libs, etc Download goldfish kernel refer - http://blog.markloiseau.com/2012/07/how-to-compile-the-android-goldfish-emulator-kernel/ Modify kernel config file (turned on Tracer Options) Boot up goldfish with custom kernel which has compiled with tracer options Tried to use Ftrace functionality The kernel freezes This is the log: \# mount -t debugfs nodev /sys/kernel/debug \# ls /sys

Apologies for the longish post, I'm having trouble formulating it in a shorter way. Also, maybe this is more appropriate for Unix & Linux Stack Exchange, but I'll try here at SO first, as there is an ftrace tag. Anyways - I'd like to observe do machine instructions of a user program execute in the context of a full function_graph capture using ftrace . One problem is that I need this for an older kernel: $ uname -a Linux mypc 2.6.38-16-generic #67-Ubuntu SMP Thu Sep 6 18:00:43 UTC 2012 i686 i686 i386 GNU/Linux ... and in this edition, there is no UPROBES - which, as Uprobes in 3.5 [LWN.net]

The goal is to examine arguments passed to specific system calls (e.g. exec, open, etc.) by any process. From the official documentation , no capability to log function arguments is described (looked mostly at the "function" tracer, as I don't need the graph). I wanted to make sure I'm not overlooking something and wasting time using something more exotic if I could actually do this within the framework of ftrace. I have limited experience with ftrace , although I have used it for for function stack traces and latency issues. (People with more experience can possibly suggest) Its pretty much

Android systrace tool, calls atrace tool via ADB. However, I don't understand very well the format of the traces file. Apparently it is very similar to linux ftrace tool with some differences. The main difference is that is doesn't uses a System.Map file but it includes all that information into the trace file. Also, there are new B|E entries that are android specific. There is some information about this format in Android Source Code at: http://androidxref.com/4.1.1/xref/external/chromium-trace/src/tracing/linux_perf_importer.js However, in that documentation we can read that the format

I want to trace a function during kernel boot process with ftrace function_graph to understand what it does, but it is not available in available_filter_functions . I tried to export it with EXPORT_SYMBOL() , guessing that it will made it available but this is not the case. Do you have a solution ? For information, functions I want to trace are persistent_ram_init_ringbuffer and persistent_ram_early_init in Android kernel 3.4. I read through the documentation but found nothing on this and grep did not helped more... Thanks The problem is that those functions are annotated with __init and _