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Date: Mon, 18 Dec 2000 21:17:34 +0100
From: Andi Kleen <ak@suse.de>
To: "Boerner, Brian" <Brian_Boerner@adaptec.com>
Cc: "'linux-kernel@vger.redhat.com'" <linux-kernel@vger.kernel.org>
Subject: Re: Disabling interrupts in 2.4.x
Message-ID: <20001218211734.A2513@gruyere.muc.suse.de>
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In-Reply-To: <E9EF680C48EAD311BDF400C04FA07B612D4DA4@ntcexc02.ntc.adaptec.com>; from Brian_Boerner@adaptec.com on Mon, Dec 18, 2000 at 02:57:19PM -0500
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> The only thing I am sure of is that interrupts are simply not disabled.

They are only disabled on the local CPU, they could still occur on other 
CPUs. This is not different from 2.2.

> 
> I've also looked at some other scsi drivers that are disabling interrupts
> and they appear to be making similar calls to spin_lock_irqsave.
> 
> Does anyone have any suggestions for debugging this? Is there a call that
> can be made to find out if interrupts are actually disabled?

unsigned flag; 
asm volatile("pushfl ; popfl %0" : "=r" (flag)); 
printk(KERN_DEBUG "local interrupts are %s\n", (flag & (1<<9)) ? "enabled" : "disabled"); 

-Andi
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