[lttng-dev] LTTng buffer mode

[Jeffrey Chen]

Thanks.
If we make changes to LTTng to add this feature, would it violate the LTTng design principle in any way? Thanks.


________________________________________
From: Philippe Proulx <eeppeliteloop at gmail.com>
Sent: Tuesday, February 16, 2016 5:02 PM
To: Jeffrey Chen
Cc: lttng-dev at lists.lttng.org
Subject: Re: [lttng-dev] LTTng buffer mode

No you cannot.

There's no hidden global buffering scheme option for user space tracing.

>From the LTTng documentation:

> In the user space tracing domain, two buffering schemes are available
> when creating a channel:
>
> Per-PID buffering: keep one ring buffer per process.
> Per-UID buffering: keep one ring buffer for all processes of a single user.

and:

> The Linux kernel tracing domain only has one available buffering scheme
> which is to use a single ring buffer for the whole system.

Phil

On Tue, Feb 16, 2016 at 7:55 PM, Jeffrey Chen <cpthk at hotmail.com> wrote:
> Hi LTTng community:
>
>
> I have a question about LTTng buffer mode. According to documentation, LTTng
> supports 2 buffer modes, per-pid, and per-uid. Is there any mode to have a
> global buffer that does not have separate buffers? The reason I asked is
> because, LTTng writes different buffer traces to different directory/file.
> It is much more difficult for us to post-process separate directories. We
> would like to have all traces write into one single buffer and
> directory/file, so it is easier to do post-processing. Thanks.
>
>
>
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