Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage!

From: Steven Rostedt
Date: Mon Nov 21 2016 - 14:06:51 EST

On Mon, 21 Nov 2016 10:37:00 -0800
Andi Kleen <andi@xxxxxxxxxxxxxx> wrote:

> Ok so how should tracing in idle code work then in your opinion?

As I suggested already. If we can get a light weight rcu_is_watching()
then we can do the rcu_idle work when needed, and not when we don't
need it. Sure this will add more branches, but that's still cheaper
than popf.

-- Steve