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Date: Thu, 14 Jan 2010 00:52:14 +0100
From: Andi Kleen <andi@firstfloor.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>, Suresh Siddha <suresh.b.siddha@intel.com>,
       Andi Kleen <andi@firstfloor.org>,
       Linus Torvalds <torvalds@linux-foundation.org>,
       "ananth@in.ibm.com" <ananth@in.ibm.com>, Ingo Molnar <mingo@elte.hu>,
       Thomas Gleixner <tglx@linutronix.de>,
       Andrew Morton <akpm@linux-foundation.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -v2 5/5] x86: use dmi check to treat disabled cpus as
	hotplug cpus.
Message-ID: <20100113235214.GG24818@basil.fritz.box>
References: <4B4D0E39.10200@kernel.org> <87tyupfzk8.fsf@basil.nowhere.org> <4B4E427D.9090207@zytor.com> <20100113222348.GE24818@basil.fritz.box> <4B4E48BB.5030902@zytor.com> <1263421753.2865.103.camel@sbs-t61.sc.intel.com> <4B4E4AE3.1030608@zytor.com> <1263422958.2865.107.camel@sbs-t61.sc.intel.com> <4B4E511C.1050609@kernel.org> <4B4E5390.1070004@zytor.com>
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> I just built an allyesconfig kernel, and it has 1904K of percpu data.
> 1791K of that is in per_cpu__cpu_lock_stats.  So everything else is

Ok so we need to fix lock stats, I'll put it on my todo list.

> ~113K.  Still.  We should not be restricted from doing legitimately
> large percpu allocations because of ghost cpus (and Tejun knows my
> position on this), but it doesn't sound like the house is burning, either.

I think it's legitimate to require explicit allocation on
add/remove event for anything large.

Static per cpu is really only for "lazy users" anyways.

-Andi
-- 
ak@linux.intel.com -- Speaking for myself only.