Re: [PATCH RFC v5 3/6] srcu: Add notrace variant of srcu_dereference

[Joel Fernandes]

On Tue, May 1, 2018 at 7:06 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> On Mon, 30 Apr 2018 18:42:01 -0700
> Joel Fernandes <joelaf@xxxxxxxxxx> wrote:

> > In this series, we are making lockdep use an rcuidle tracepoint. For
> > this reason we need a notrace variant of srcu_dereference since
> > otherwise we get lockdep splats since lockdep hooks may not have run
> > yet. This patch adds the needed variant.

> This change log is rather confusing. Why would lockdep use an rcuidle
> tracepoint? I think we need to explain more here.

Patch 6/6 registers lockdep onto irq_disable and irq_enable tracepoints
which use rcuidle:
https://github.com/torvalds/linux/blob/master/kernel/trace/trace_irqsoff.c#L791

I can add more details to the change log about this.

thanks,

- Joel