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Date: Tue, 6 Mar 2001 15:53:45 -0800 (PST)
From: Nigel Gamble <nigel@nrg.org>
Reply-To: nigel@nrg.org
To: Manoj Sontakke <manojs@sasken.com>
cc: linux-kernel@vger.kernel.org
Subject: Re: spinlock help
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On Tue, 6 Mar 2001, Manoj Sontakke wrote:
> 1. when spin_lock_irqsave() function is called the subsequent code is
> executed untill spin_unloc_irqrestore()is called. is this right?

Yes.  The protected code will not be interrupted, or simultaneously
executed by another CPU.

> 2. is this sequence valid?
> 	spin_lock_irqsave(a,b);
> 	spin_lock_irqsave(c,d);

Yes, as long as it is followed by:

	spin_unlock_irqrestore(c, d);
	spin_unlock_irqrestore(a, b);

Nigel Gamble                                    nigel@nrg.org
Mountain View, CA, USA.                         http://www.nrg.org/

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