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Date: Mon, 23 Mar 2015 09:43:13 -0700
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@kernel.org>, Petr Mladek <pmladek@suse.cz>,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
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        Ananth NMavinakayanahalli <ananth@in.ibm.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Ingo Molnar <mingo@redhat.com>, Jiri Kosina <jkosina@suse.cz>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] kprobes: Disable Kprobe when ftrace arming fails
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On Mon, Mar 23, 2015 at 09:43:17AM -0400, Steven Rostedt wrote:
> On Mon, 23 Mar 2015 14:34:42 +0100
> Ingo Molnar <mingo@kernel.org> wrote:
> > 
> > Even if it was documented (it isn't), it's pretty weird terminology - 
> > please use clearer formulations, like 'patched function' or 'unpatched 
> > function' or 'function with pending patch'. No need to redefine 
> > existing words in a weird fashion just to create the appearance of 
> > being special ...
> > 
> 
> I think it has to do with their RCU like patching functionality, where
> some tasks are still executing the old function and others are
> executing the new function. In RCU, there's two "universes" too. One
> with the old value, and one with the new. After the grace period has
> finished, everything is back to a single "universe".
> 
> I'm not sure RCU uses the term "universe" though. Paul?

I have used "version" for what you call "universe", but mostly in
"intro to RCU" guest lectures.

							Thanx, Paul