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Subject: Re: [PATCH] Prevent nested interrupts when the IRQ stack is near
 overflowing v2
From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>, Andi Kleen <andi@firstfloor.org>,
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Date: Thu, 25 Mar 2010 19:23:58 +0100
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On Thu, 2010-03-25 at 19:21 +0100, Peter Zijlstra wrote:
> On Thu, 2010-03-25 at 11:01 -0700, Linus Torvalds wrote:
> > Are there any cases around 
> > that still have busy-loop delays based on real-time in their irq handlers? 
> > I simply don't know. 
> 
> I recently found a few in drivers/net/ there's all kinds of funny stuff
> in there.. not sure how common the matching hardware is though.
> 
> One thing we could do is instrument jiffies to yell when its used from
> hardirq context and fix up these things.

Also, Arjan mentioned he wanted to sweep the kernel for jiffies users
and convert them to timer interfaces..