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Date: Sun, 24 Feb 2008 11:46:39 +0100
From: Kris Kennaway <kris@FreeBSD.org>
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To: Barney Cordoba <barney_cordoba@yahoo.com>
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Cc: current@freebsd.org
Subject: Re: splimp()
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Barney Cordoba wrote:
> I'm porting some older software to 7.0 and I see that
> many of the 7.0 drivers use both locks and splimps()
> to protect code, particularly the firewire driver.
> What cases would an splimp() be required?

spl*() are NOPs that are only left behind in some code as a reminder of 
what mutual exclusion protections used to apply, mostly in cases where 
there has not been fine-grained locking applied to the code in question. 
  In some (most?) cases they serve no useful annotation purpose and 
should just be removed.  For newly written code they should be added.

Kris