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Date: Mon, 9 Sep 2002 12:06:26 +0200 (CEST)
From: Ingo Molnar <mingo@elte.hu>
Reply-To: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Zwane Mwaikambo <zwane@mwaikambo.name>, Robert Love <rml@tech9.net>,
       Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH][RFC] per isr in_progress markers
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On Sun, 8 Sep 2002, Linus Torvalds wrote:

> As far as I can tell, the only time when this might be an advantage is
> an SMP machine with multiple devices sharing an extremely busy irq line.
> Then the per-isr in-progress bit allows multiple CPU's to actively
> handle several of the devices at the same time.
> 
> Or is there some other case where this is helpful?

it could also improve latency of a faster interrupt source that shares its
irq line with a slow (but still frequent) handler. (such as SCSI or ne2k.)  
This is both on UP and on SMP.

although this might be less of an issue these days.

	Ingo

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