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Subject: Re: [PATCH][RFC] preempt_count corruption across H_CEDE call with
	CONFIG_PREEMPT on pseries
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Darren Hart <dvhltc@us.ibm.com>
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On Thu, 2010-07-22 at 11:24 -0700, Darren Hart wrote:
> 
> 1) How can the preempt_count() get mangled across the H_CEDE hcall?
> 2) Should we call preempt_enable() in cpu_idle() prior to cpu_die() ?

The preempt count is on the thread info at the bottom of the stack.

Can you check the stack pointers ?

Cheers,
Ben.