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From: Arnd Bergmann <arnd@arndb.de>
To: John Kacur <jkacur@redhat.com>
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>
Subject: Re: [PATCH RFC] BKL not necessary in cpuid_open
Date: Fri, 9 Oct 2009 18:05:11 +0200	[thread overview]
Message-ID: <200910091805.11249.arnd@arndb.de> (raw)
In-Reply-To: <alpine.LFD.2.00.0910072016190.15183@localhost.localdomain>

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

  parent reply	other threads:[~2009-10-09 16:06 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-07 18:19 [PATCH RFC] BKL not necessary in cpuid_open John Kacur
2009-10-07 19:12 ` Frederic Weisbecker
2009-10-07 19:14 ` Sven-Thorsten Dietrich
2009-10-07 19:31   ` John Kacur
2009-10-07 20:00     ` Sven-Thorsten Dietrich
2009-10-07 19:43 ` [PATCH] x86: Remove the bkl from msr_open() Frederic Weisbecker
2009-10-07 20:15   ` John Kacur
2009-10-07 21:10   ` [tip:x86/cpu] x86, msr: " tip-bot for Frederic Weisbecker
2009-10-07 20:13 ` [PATCH RFC] BKL not necessary in cpuid_open Frederic Weisbecker
2009-10-07 21:01   ` Thomas Gleixner
2009-10-07 21:44     ` Frederic Weisbecker
2009-10-07 21:58     ` John Kacur
2009-10-10 21:18       ` Frederic Weisbecker
2009-10-07 22:43 ` [tip:x86/cpu] x86, cpuid: Remove the bkl from cpuid_open() tip-bot for John Kacur
2009-10-09 16:05 ` Arnd Bergmann [this message]
     [not found] <1033457751.1452271255124941735.JavaMail.root@zmail07.collab.prod.int.phx2.redhat.com>
2009-10-09 21:55 ` [PATCH RFC] BKL not necessary in cpuid_open John Kacur

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