Re: [patch V2 21/29] tracing: Use percpu stack trace buffer more intelligently

Steven Rostedt
2019-04-18T15:46:47Z

On Thu, 18 Apr 2019 17:43:59 +0200 (CEST)
Thomas Gleixner <tglx@linutronix.de> wrote:

> On Thu, 18 Apr 2019, Steven Rostedt wrote:
> > On Thu, 18 Apr 2019 10:41:40 +0200
> > Thomas Gleixner <tglx@linutronix.de> wrote:
> > > -static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
> > > +/* This allows 8 level nesting which is plenty */
> >
> > Can we make this 4 level nesting and increase the size? (I can see us
> > going more than 64 deep, kernel developers never cease to amaze me ;-)
> > That's all we need:
> >
> > Context: Normal, softirq, irq, NMI
> >
> > Is there any other way to nest?
>
> Not that I know, but you are the tracer dude :)
>

There's other places I only test 4 deep, so it should be fine to limit
it to 4 then.

Thanks!

-- Steve