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Date: Tue, 31 Oct 2017 08:24:28 +1100
From: "Tobin C. Harding" <me@tobin.cc>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>,
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Subject: Re: [PATCH v7] printk: hash addresses printed with %p
Message-ID: <20171030212428.GR12341@eros>
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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@tobin.cc> 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.