From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH -v5][RFC]: mutex: implement adaptive spinning
Date: Thu, 8 Jan 2009 07:52:35 +0100
Message-ID: <20090108065235.GX496@one.firstfloor.org>
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Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Dave Kleikamp <shaggy@linux.vnet.ibm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	paulmck@linux.vnet.ibm.com, Gregory Haskins <ghaskins@novell.com>,
	Ingo Molnar <mingo@elte.hu>, Matthew Wilcox <matthew@wil.cx>,
	Andi Kleen <andi@firstfloor.org>,
	Chris Mason <chris.mason@oracle.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-btrfs <linux-btrfs@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Nick Piggin <npiggin@suse.de>,
	Peter Morreale <pmorreale@novell.com>,
	Sven Dietrich <SDietrich@novell.com>
To: Steven Rostedt <rostedt@goodmis.org>
Return-path: <linux-fsdevel-owner@vger.kernel.org>
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List-ID: <linux-btrfs.vger.kernel.org>

> What about memory hotplug as Ingo mentioned?
> 
> Should that be:
> 
> #if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_MEMORY_HOTPLUG)

We expect memory hotunplug to only really work in movable zones
(all others should at least have one kernel object somewhere that prevents
unplug) and you can't have task structs in movable zones obviously

So it's probably a non issue in practice.

-Andi
-- 
ak@linux.intel.com