Re: [PATCH v7] printk: hash addresses printed with %p

From: Tobin C. Harding
Date: Mon Oct 30 2017 - 17:24:36 EST


On Mon, Oct 30, 2017 at 04:22:44PM -0400, Steven Rostedt wrote:
> On Wed, 25 Oct 2017 14:49:34 +1100
> "Tobin C. Harding" <me@xxxxxxxx> wrote:
> >
> > First, the static_key stuff.
> >
> > DEFINE_STATIC_KEY_TRUE(no_ptr_secret) : Doesn't sleep, just a
> > declaration.
> >
> > if (static_branch_unlikely(&no_ptr_secret)) {} : Doesn't sleep, just
> > some assembler to jump to returning true or false.
> >
> > static_branch_disable(&no_ptr_secret) : Doesn't sleep, just atomic read
> > and set and maybe a WARN_ONCE.
>
> How quickly do you need static_branch_disable() executed? You could
> always pass the work off to a worker thread (that can schedule).
>
> random_ready_callback -> initiates worker thread -> enables the static branch
>
> -- Steve

thanks Steve, v8 and onward does away with the static branch and uses a
global boolean instead.

thanks,
Tobin.