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Subject: Re: [patch] rt: res_counter fix, v2
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>, Thomas Gleixner <tglx@tglx.de>,
       LKML <linux-kernel@vger.kernel.org>,
       rt-users <linux-rt-users@vger.kernel.org>,
       Steven Rostedt <rostedt@goodmis.org>, Carsten Emde <ce@ceag.ch>,
       Clark Williams <williams@redhat.com>
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Date: Thu, 12 Feb 2009 15:51:46 +0100
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On Thu, 2009-02-12 at 15:46 +0100, Ingo Molnar wrote:
> * Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> 
> > On Thu, 2009-02-12 at 15:28 +0100, Frederic Weisbecker wrote:
> > > > [   45.228589] hardirqs last disabled at (0): [<ffffffff8025449d>] copy_process+0x68d/0x1500
> > > > [   45.228602] softirqs last  enabled at (0): [<ffffffff8025449d>] copy_process+0x68d/0x1500
> > > 
> > > 
> > > The reason for which I wanted to send an irqsoff trace is that the above lines are false.
> > 
> > copy_process() has:
> > 
> > #endif
> > 	p->hardirq_enable_ip = 0;
> > 	p->hardirq_enable_event = 0;
> > 	p->hardirq_disable_ip = _THIS_IP_;
> > 	p->hardirq_disable_event = 0;
> > 	p->softirqs_enabled = 1;
> > 	p->softirq_enable_ip = _THIS_IP_;
> > 	p->softirq_enable_event = 0;
> > 	p->softirq_disable_ip = 0;
> > 	p->softirq_disable_event = 0;
> > 	p->hardirq_context = 0;
> > 	p->softirq_context = 0;
> > #endif
> > 
> > the sequence count of 0 basically tells you it hasn't been set yet.
> 
> maybe we should initialize it to -1 to make this more apparent?

I think the current state makes sense, it reflects the actual state of
copy_process.