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Date: Thu, 3 Jul 2008 08:18:02 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Hugh Dickins <hugh@veritas.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
       Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
       Peter Jones <pjones@redhat.com>, Glauber Costa <gcosta@redhat.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       Yinghai Lu <yhlu.kernel@gmail.com>, Huang@elte.hu,
       Ying <ying.huang@intel.com>
Subject: Re: [PATCH] x86: fix Intel Mac booting with EFI
Message-ID: <20080703061802.GC9884@elte.hu>
References: <Pine.LNX.4.64.0807022239520.24137@blonde.site>
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* Hugh Dickins <hugh@veritas.com> wrote:

> Fedora reports that mem_init()'s zap_low_mappings(), extended to SMP 
> in 61165d7a035f6571c7576e7f51e7230157724c8d x86: fix app crashes after 
> SMP resume causes 32-bit Intel Mac machines to reboot very early when 
> booting with EFI.
> 
> The EFI code appears to manage low mappings for itself when needed; 
> but like many before it, confuses PSE with PAE.  So it has only been 
> mapping half the space it needed when PSE but not PAE.  This remained 
> unnoticed until we moved the SMP zap_low_mappings() before 
> efi_enter_virtual_mode().  Presumably could have been noticed years 
> ago if anyone ran a UP kernel on such machines?

good spotting!

Acked-by: Ingo Molnar <mingo@elte.hu>

	Ingo