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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Takeharu KATO <kato.takeharu@jp.fujitsu.com>
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Date: Wed, 16 Mar 2005 11:18:05 +1100
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Subject: Re: boot time scheduling hile atomic
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On Fri, 2005-03-11 at 15:19 +0900, Takeharu KATO wrote:
> Hi Joerg:
> 
> First of all, I am sorry to making mistake on my stack analysis.
> After all, I found what is wrong.
> 
> The syscall_exit_work is called(jumped) by fork, strictly speaking,
> this is caused by kernel_thead for init process.
> At this point, kernel set a need_resched flag in thread_info struct
> (flags member).
> So, the system executes syscall_exit_work when
> the swapper thread exited from syscall.
> 
> However, the syscall_exit_work routine does not check
> preempt counts when it calls schedule function.
> 
> FYI, I post the patch which fix this problem.
> I've confirmed the problem has been removed by this patch,
> but I can not figure out whether it is truely
> correct or not.

I think the problem is more why are we calling a syscall while the
preempt count is up ?

Ben.