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Date: Mon, 31 May 2004 17:50:50 +1000
From: Nick Piggin <nickpiggin@yahoo.com.au>
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To: Keith Owens <kaos@ocs.com.au>
CC: linux-kernel@vger.kernel.org
Subject: Re: 2.6.7-rc2 mismatched preempt count in arch/i386/kernel/irq.c
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Keith Owens wrote:
> 2.6.7-rc2 (and earlier) arch/i386/kernel/irq.c::do_IRQ() calls
> irq_exit() which expands into preempt_enable_no_resched(), amongst
> others.  With CONFIG_PREEMPT=y, preempt_enable_no_resched() does
> dec_preempt_count().  Where is the corresponding inc_preempt_count?
> AFAICT the use of preempt_enable_no_resched() is unbalanced.
> 

If preempt is enabled, IRQ_EXIT_OFFSET is HARDIRQ_OFFSET-1.

I believe that is where the preempt_enable_no_resched is balanced.