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Re: [PATCH v2 07/12] sched: Robustify preemption leak checks

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On Wed, 30 Sep 2015 09:10:42 +0200
Peter Zijlstra <peterz@infradead.org> wrote:

> When we warn about a preempt_count leak; reset the preempt_count to
> the known good value such that the problem does not ripple forward.
> 
> This is most important on x86 which has a per cpu preempt_count that is
> not saved/restored (after this series). So if you schedule with an
> invalid (!2*PREEMPT_DISABLE_OFFSET) preempt_count the next task is
> messed up too.
> 
> Enforcing this invariant limits the borkage to just the one task.
> 
> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

Reviewed-by: Steven Rostedt <rostedt@goodmis.org>

-- Steve

> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---

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[PATCH v2 07/12] sched: Robustify preemption leak checks Peter Zijlstra <peterz@infradead.org> - 2015-09-30 09:40 +0200
  Re: [PATCH v2 07/12] sched: Robustify preemption leak checks Steven Rostedt <rostedt@goodmis.org> - 2015-09-30 11:40 +0200

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