From mboxrd@z Thu Jan  1 00:00:00 1970
From: ykzhao <yakui.zhao@intel.com>
Subject: Re: [PATCH] x86: make sure wakeup code is below 1M -v2
Date: Thu, 12 Nov 2009 09:17:12 +0800
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To: Yinghai Lu <yinghai@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>, Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>, Len Brown <lenb@kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, ACPI Devel Maling List <linux-acpi@vger.kernel.org>, pm list <linux-pm@lists.linux-foundation.org>

On Thu, 2009-11-12 at 03:05 +0800, Yinghai Lu wrote:
> ykzhao wrote:
> > On Wed, 2009-11-11 at 10:27 +0800, Yinghai Lu wrote:
> >> try to find_e820_area/reserve_early, and call acpi_reserve_memory early
> >>
> >> to get area is below 1M
> >>
> >> -v2: change function name to acpi_reserve_wakeup_memory according to Rafael
> > It seems that the function of find_e820_area is called in several
> > places.
> >    >Initmem_init: bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT,
> > bootmap_size, PAGE_SIZE);
> >    
> > If we also call it in the acpi_reserve_wakeup_memory, do we get the same
> > base address as that obtained in initmem_init?
> 
> no. find_e820_area will check the reserve res array that could be updated by reserve_early.
It will check the reserved region array when calling the function of
find_e820_area. 
But it seems that the array is not updated when the find_e820_area is
called in the function of initmem_init.

At the same time the  acpi_reserve_bootmem is called after initializing
the boot mem allocator. Can we continue to reserve some region by using
find_e820_area?

thanks.
> 
> YH