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From: Andi Kleen <andi@firstfloor.org>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Martin Steigerwald <ms@teamix.de>,
	linux-kernel@vger.kernel.org, Andi Kleen <andi@firstfloor.org>,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: physical memory limit of 64-bit linux
Date: Tue, 16 Dec 2008 17:44:43 +0100	[thread overview]
Message-ID: <20081216164443.GY25779@one.firstfloor.org> (raw)
In-Reply-To: <200812161654.17291.rjw@sisk.pl>

On Tue, Dec 16, 2008 at 04:54:16PM +0100, Rafael J. Wysocki wrote:
> On Tuesday, 16 of December 2008, Martin Steigerwald wrote:
> > 
> > Hi!
> > 
> > What is the physical memory limit for 64-bit Linux? I read about 40 bit 
> > address bus for AMD Athlon X2 (1 TB) and 48 bit for Barcelona X4 (256 TB).
> > 
> > Is 64-bit linux able to use that amount - provided that one would manage to 
> > build it into a machine? Or does it have a lower limit?

It depends on which 64bit Linux; e.g. IA64 has larger limits.

> > Looking into the Google crystal ball gives unclear pictures... I tend to 
> > assume that Linux would handle it, but I am not sure.
> 
> IIRC, the current maximal virtual memory space size of the kernel on x86_64 is 2^46.

Correct.

-Andi

-- 
ak@linux.intel.com

  reply	other threads:[~2008-12-16 16:32 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-16 14:56 physical memory limit of 64-bit linux Martin Steigerwald
2008-12-16 15:54 ` Rafael J. Wysocki
2008-12-16 16:44   ` Andi Kleen [this message]
2008-12-17 14:12     ` Martin Steigerwald
2008-12-16 18:47   ` Ingo Molnar
2008-12-16 19:07     ` Jeremy Fitzhardinge
2008-12-16 19:23       ` Ingo Molnar
2008-12-16 19:28     ` Andi Kleen
2008-12-17 14:30     ` Martin Steigerwald

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