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From: "H. Peter Anvin" <hpa@zytor.com>
To: Alexander van Heukelum <heukelum@mailshack.com>
Cc: Andi Kleen <ak@suse.de>, Ingo Molnar <mingo@elte.hu>,
	Thomas Gleixner <tglx@linutronix.de>,
	LKML <linux-kernel@vger.kernel.org>,
	Alexander van Heukelum <heukelum@fastmail.fm>
Subject: Re: [PATCH] Fix alignment of early reservation for EBDA
Date: Sun, 24 Feb 2008 18:18:16 -0800	[thread overview]
Message-ID: <47C22568.1010405@zytor.com> (raw)
In-Reply-To: <20080224174605.GA21661@mailshack.com>

Alexander van Heukelum wrote:
> Hi Andi,
> 
> My eyes fell on the following table in the boot messages:
> 
> early res: 0 [0-fff] BIOS data page
> early res: 1 [6000-7fff] SMP_TRAMPOLINE
> early res: 2 [200000-374557] TEXT DATA BSS
> early res: 3 [9fc00-a0bff] EBDA
> early res: 4 [8000-afff] PGTABLE
> 
> The memory reserved for the EBDA overflows into the area normally
> reserved for the VGA adaptor. It seems that you wanted to force
> the allocation to cover whole pages, like:
> 
> early res: 3 [9f000-9ffff] EBDA
> 
> This is what this patch implements.
> 
> Is it really necessary to force the allocation to a page boundary?
> 

It is, but that rounding gets done in reserve_bootmem() anyway, so there 
is no need for the arch-specific code to do it.

The 32-bit EBDA code hard-codes a size of 4K, which is probably equally 
wrong; my gut feel is that the right thing to do is to reserve from the 
EBDA up to the 640K mark (some BIOSes use an area like that for SMM 
stuff), possibly with some sanity checking.

	-hpa

  parent reply	other threads:[~2008-02-25  2:18 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-24 17:46 Alexander van Heukelum
2008-02-24 19:27 ` Andi Kleen
2008-02-24 19:41 ` Ingo Molnar
2008-02-24 20:53   ` Alexander van Heukelum
2008-02-25  2:18 ` H. Peter Anvin [this message]
2008-02-25 16:54   ` Alexander van Heukelum
2008-02-25 17:01     ` Ingo Molnar
2008-02-25 18:07       ` [PATCH] reserve_early end-of-conventional-memory to 1MB Alexander van Heukelum
2008-02-25 18:13         ` H. Peter Anvin
2008-02-25 19:46           ` Alexander van Heukelum
2008-02-25 21:17             ` H. Peter Anvin
2008-02-26  9:30             ` Ingo Molnar
2008-02-27 14:26               ` Andi Kleen
2008-02-27 14:38               ` [PATCH] reserve_early end-of-conventional-memory to 1MB II - some numbers to put it into perspective Andi Kleen
2008-02-27 16:44                 ` H. Peter Anvin
2008-02-27 20:01                 ` Alexander van Heukelum
2008-02-28 13:13         ` [PATCH] reserve end-of-conventional-memory to 1MB on 32-bit Alexander van Heukelum
2008-02-28 13:28           ` [RFC] use realmode code to reserve end-of-conventional-memory to 1MB Alexander van Heukelum
2008-02-28 21:12             ` Ian Campbell
2008-02-28 21:14               ` H. Peter Anvin
2008-02-28 23:16                 ` Ian Campbell
2008-02-29 20:00                   ` Ingo Molnar
2008-03-04 11:41                   ` Mark McLoughlin
2008-03-04 14:33                     ` Ingo Molnar
2008-03-04 15:12                       ` Ian Campbell
2008-03-04 15:13                       ` Jeremy Fitzhardinge
2008-03-04 15:25                         ` Ingo Molnar
2008-03-04 16:02                           ` Jeremy Fitzhardinge
2008-03-04 16:15                             ` Ingo Molnar
2008-03-04 16:15                       ` Mark McLoughlin
2008-03-04 16:23                         ` Ingo Molnar
2008-03-04 17:44                   ` Jeremy Fitzhardinge
2008-03-05 15:59                   ` Eduardo Habkost
2008-03-05 16:08                     ` H. Peter Anvin
2008-03-05 16:53                       ` Eduardo Habkost
2008-03-05 17:28                         ` H. Peter Anvin
2008-03-05 17:28                           ` Jeremy Fitzhardinge
2008-03-05 17:38                             ` H. Peter Anvin
2008-03-05 16:38                     ` Jeremy Fitzhardinge
2008-03-05 17:27                       ` H. Peter Anvin
2008-02-28 21:09           ` [PATCH] reserve end-of-conventional-memory to 1MB on 32-bit Ian Campbell
2008-02-29 11:49             ` Alexander van Heukelum
2008-02-29 17:14               ` Mark McLoughlin
2008-02-29 18:38                 ` Alexander van Heukelum
2008-02-29 18:44                   ` H. Peter Anvin
2008-02-29 18:56                     ` Alexander van Heukelum
2008-02-29 22:06                   ` Mark McLoughlin
2008-02-29 22:26                     ` Alexander van Heukelum
2008-03-01 16:09                     ` [PATCH] reserve end-of-conventional-memory to 1MB on 32-bit v2 Alexander van Heukelum
2008-03-01 16:12                       ` [PATCH] reserve end-of-conventional-memory to 1MB on 64-bit add-on Alexander van Heukelum
2008-03-04 11:44                       ` [PATCH] reserve end-of-conventional-memory to 1MB on 32-bit v2 Mark McLoughlin
2008-03-04 13:31                         ` Alexander van Heukelum
2008-03-04 14:49                         ` Ingo Molnar
2008-03-04 15:16                           ` Mark McLoughlin
2008-03-04 15:24                             ` Ingo Molnar
2008-03-04 15:18                         ` Jeremy Fitzhardinge
2008-03-04 16:51                           ` Alexander van Heukelum
2008-03-04 17:05                             ` H. Peter Anvin
2008-03-04 17:11                             ` Jeremy Fitzhardinge
2008-03-04 18:57                               ` [PATCH] reserve end-of-conventional-memory to 1MB, 32-bit, use paravirt_enabled Alexander van Heukelum
2008-03-04 19:12                                 ` [PATCH] reserve end-of-conventional-memory to 1MB, 64-bit, " Alexander van Heukelum
2008-02-27 14:25     ` [PATCH] Fix alignment of early reservation for EBDA Andi Kleen

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