Re: [RFC PATCH v2 2/3] tracefs: add instances support for uprobe events

From: Aravinda Prasad
Date: Wed Aug 03 2016 - 15:31:14 EST




On Tuesday 02 August 2016 11:19 PM, Steven Rostedt wrote:
> On Tue, 2 Aug 2016 22:57:30 +0530
> Hari Bathini <hbathini@xxxxxxxxxxxxxxxxxx> wrote:
>
>> where a mountable instance is more than a trace array.
>> This may need addition of new flags for trace array saying
>> whether it is a global trace or directory instance or mountable instance.
>> Also, the helper functions that add/remove events need to be tweaked
>> accordingly.
>
> BTW, I'm curious to how you handle the rest of the trace files in a
> container? The tracing system really looks at the Linux kernel as a
> whole, and for the most part ignores things like name spaces.

We started by trying to support perf inside a container and currently we
are exploring approaches to support function tracing inside a container.

One approach that we are thinking/working is on the lines of patch 1/3.
For example, filtering events based on the namespace in which the trace
file is read. We are trying to understand the ftrace implementation and
hence not sure if this is feasible.

We would be happy to explore if you have any suggestions/feedback on
supporting function tracing inside a container.

>
> Can a container have its own function tracing?

Sorry, I didn't understand that. Do you mean to have a separate
per-container trace files?

Regards,
Aravinda

>
> -- Steve
>

--
Regards,
Aravinda