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Subject: Re: irq-disabled vs vmap vs text_poke
From: Peter Zijlstra <peterz@infradead.org>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ingo Molnar <mingo@elte.hu>, Nick Piggin <npiggin@suse.de>,
       akpm <akpm@linux-foundation.org>,
       linux-kernel <linux-kernel@vger.kernel.org>
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Date: Fri, 13 Feb 2009 15:33:46 +0100
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On Fri, 2009-02-13 at 09:25 -0500, Mathieu Desnoyers wrote:
> * Ingo Molnar (mingo@elte.hu) wrote:
> > 
> > * Peter Zijlstra <peterz@infradead.org> wrote:
> > 
> > > > I think I got a mostly working patch cobbled together sitting here
> > > > somewhere. I was waiting for some _really_ good use case before spending
> > > > more time on it. I would prefer if at all possible to do vmap operations
> > > > in sleepable, process context.
> > > 
> > > Agreed, I think we want to fix text_poke() and make the vmap/vunmap()
> > > ops yell louder at violations of these rules.
> > > 
> > > I'm just totally clueless wrt text_poke() hence this email ;-)
> > 
> > also, this started triggering yesterday for the first time - and never
> > saw it before. Has some commit caused this side-effect?
> > 
> > It triggers during kprobes self-test - has that been improved recently?
> > 
> 
> When is this self-test run ? If it's at early boot while still in UP
> with interrupts off, kprobes should probably use text_poke_early()
> rather than text_poke().

Looking at the dmesg it looks to be post smp-init, so its late init
calls.

I think its the do_initcalls() from do_basic_setup(). So the machine
should be mostly up and running.