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

[Steven Rostedt]

On Wed, 30 Sep 2015 09:10:42 +0200
Peter Zijlstra <peterz@xxxxxxxxxxxxx> 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@xxxxxxxxx>
> Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Reviewed-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

-- Steve

> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---

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