Re: [PATCH v1] trace-cmd: introduce --initital-delay for record command

From: Steven Rostedt
Date: Mon Dec 18 2017 - 12:52:42 EST

On Mon, 18 Dec 2017 17:23:24 +0100
David Hildenbrand <david@xxxxxxxxxx> wrote:

> What I need: Start tracing and flush all buffers when exiting. (e.g.

Why don't you use "trace-cmd start" and "trace-cmd extract"?

"trace-cmd record" is all about not losing events. If you are creating
a big buffer, then I think you want to use this.

# trace-cmd start -p <tracer> -e <events> -b <big-buffer-size>
# run test
# trace-cmd stop
# trace-cmd extract

Wouldn't that work for you?

-- Steve

> after 30 seconds). Never wakeup in between, so the real trace overhead
> in that period of time is purely storing the tracepoints to the buffer
> in the kernel. Of course we could implement something like that ("copy
> from the buffer only when exiting") or try to see if we can fix the
> existing "-s" flag in a way that allows it.