From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH RFC] BKL not necessary in cpuid_open
Date: Fri, 9 Oct 2009 18:05:11 +0200
Message-ID: <200910091805.11249.arnd@arndb.de>
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Cc: tglx@linutronix.de, Ingo Molnar <mingo@elte.hu>,
	linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org,
	Clark Williams <williams@redhat.com>
To: John Kacur <jkacur@redhat.com>
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On Wednesday 07 October 2009, John Kacur wrote:
> 
> I've been staring at the BKL lock in cpuid_open, and I can't see what it 
> is protecting. However, I may have missed something - even something 
> obvious, so comments are welcome.
> 

Hi John,

In general, the lock_kernel() calls in any chardev open() file operation
are the result of the BKL pushdown by Jon Corbet and others, which has happened
some time last year[1]. I'd assume that the vast majority is not needed
at all, so these are an easy target for removal.

	Arnd

[1] http://lkml.indiana.edu/hypermail/linux/kernel/0805.2/0257.html