Messages in this thread | | | Date | Thu, 13 Dec 2012 15:00:15 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] context_tracking: Add comments on interface and internals |
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On Thu, 13 Dec 2012 23:50:23 +0100 Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > > >> + * This call supports re-entrancy. > > > > Presumably the explanation for user_exit() applies here. > > Not sure what you mean here.
It's unclear what it means to say "user_enter() supports reentrancy". I mean, zillions of kernel functions are surely reentrant - so what? It appears that you had something in mind when pointing this out, but what was it? The comment over user_exit() appears to tell us.
> > It's mainly this bit which makes me wonder why the code is in lib/. Is > > there any conceivable prospect that any other subsystem will use this > > code for anything? > > So that's because of that cputime accounting on dynticks CPUs which > will need to know about user/kernel transitions. I'm preparing that > for the 3.9 merge window.
Oh. That's really the entire reason for the patch and should have been in the changelog!
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