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Date: Wed, 11 Nov 2009 23:20:15 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: ykzhao <yakui.zhao@intel.com>
CC: Yinghai Lu <yinghai@kernel.org>, "Rafael J. Wysocki" <rjw@sisk.pl>,
       Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
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Subject: Re: [PATCH] x86: make sure wakeup code is below 1M -v2
References: <4AF7D820.5040503@kernel.org> <200911091315.13151.rjw@sisk.pl>	 <4AFA210B.3020207@kernel.org>	 <1257930767.31183.113.camel@localhost.localdomain>	 <4AFB0B02.4050306@kernel.org>	 <1257988632.31183.134.camel@localhost.localdomain>	 <4AFB7D21.6050004@kernel.org>	 <1257997072.3888.4.camel@localhost.localdomain>	 <4AFB9B60.7010009@kernel.org> <1258010067.3802.11.camel@localhost.localdomain>
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On 11/11/2009 11:14 PM, ykzhao wrote:
> 
> In this patch the find_e820_area is used in the
> acpi_reserve_wakeup_memory, which is called after initializing the
> bootmem allocator.
> Can we still use the find_e820_area after the bootmem allocator is
> initialized? 

Obviously not: the bootmem allocator now thinks it owns memory, and it
wouldn't know not to allocate something that is later claimed by
find_e820_area.  Problem.

> It seems that the bootmem bitmap is also found by using the
> find_e820_area. But we don't update the reserved_early array any more.
> Maybe we will get the overlap address with the bootmem bitmap for the
> wakeup code.

Not just the bitmap, but any bootmem allocation could conflict...

	-hpa
-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.