Re: [PATCH v2] tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 5 May 2025 11:48:49 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

> From: Steven Rostedt <rostedt@goodmis.org>
> 
> The per CPU "disabled" value was the original way to disable tracing when
> the tracing subsystem was first created. Today, the ring buffer
> infrastructure has its own way to disable tracing. In fact, things have
> changed so much since 2008 that many things ignore the disable flag.
> 
> The kdb_ftdump() function iterates over all the current tracing CPUs and
> increments the "disabled" counter before doing the dump, and decrements it
> afterward.
> 
> As the disabled flag can be ignored, doing this today is not reliable.
> Instead, simply call tracer_tracing_off() and then tracer_tracing_on() to
> disable and then enabled the entire ring buffer in one go!
> 
> Cc: Jason Wessel <jason.wessel@windriver.com>
> Cc: Daniel Thompson <danielt@kernel.org>
> Cc: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> Changes since v1: https://lore.kernel.org/20250502205348.643055437@goodmis.org
> 
> - Remove unused "int cpu;" (kernel test robot)

Ignore this patch, I'll send out a full series of v2 again, but this time
adding a tracer_tracing_disable/enable() functions.

-- Steve