From: Rusty Russell <rusty@rustcorp.com.au>
To: Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH 0/5] ftrace: to kill a daemon
Date: Mon, 11 Aug 2008 12:41:22 +1000
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Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
       linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
       Thomas Gleixner <tglx@linutronix.de>,
       Peter Zijlstra <peterz@infradead.org>,
       Andrew Morton <akpm@linux-foundation.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       David Miller <davem@davemloft.net>, Roland McGrath <roland@redhat.com>,
       Ulrich Drepper <drepper@redhat.com>,
       Jeremy Fitzhardinge <jeremy@goop.org>,
       Gregory Haskins <ghaskins@novell.com>,
       Arnaldo Carvalho de Melo <acme@redhat.com>,
       "Luis Claudio R. Goncalves" <lclaudio@uudg.org>,
       Clark Williams <williams@redhat.com>
References: <20080807182013.984175558@goodmis.org> <20080808182104.GA11376@Krystal> <alpine.DEB.1.10.0808081432400.8922@gandalf.stny.rr.com>
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On Saturday 09 August 2008 04:41:06 Steven Rostedt wrote:
> On Fri, 8 Aug 2008, Mathieu Desnoyers wrote:
> > kstop_machine does not guarantee that you won't have _any_ thread
> > preempted with IP pointing exactly in the middle of your instructions
> > _before_ the modification scheduled back in _after_ the modification and
> > thus causing an illegal instruction.
> >
> > Still buggy. :/
>
> Hmm, good point. Unless...

You can walk the task list and fix them up, if you have to.  Of course, this 
could be extremely slow with a million threads.  Maybe just walking the 
runqueues would be sufficient?

Rusty.
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