Re: [PATCH] selftests/ftrace: Limit number of lines processed in 'trace'

[Steven Rostedt]

On Wed, 19 Oct 2022 00:19:49 +0900
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote:

> > You need to make sure that the "pause-on-trace" option is set or tracing_on
> > is set to 0 (disabled). Otherwise, if the tracing is still active, then the
> > reading of the trace file could potentially never end.  
> 
> initialize_ftrace() does this setting. So it must be set.
> If you run the ftracetest on old kernel, this feature is not there and
> it may cause a trouble. Naveen, can you clarify it?

But for old kernels that do not have "pause-on-trace" it should be the
default. The "pause-on-trace" was added when the default was changed to not
pause the trace while reading it.

-- Steve