Re: [PATCH v3] kprobes: Disable Kprobe when ftrace arming fails

From: Paul E. McKenney
Date: Mon Mar 23 2015 - 12:43:25 EST

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@xxxxxxxxxx> 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

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