All of lore.kernel.org
 help / color / mirror / Atom feed
From: Robert Hancock <hancockr@shaw.ca>
To: Jeff Chua <jeff.chua.linux@gmail.com>
Cc: lkml <linux-kernel@vger.kernel.org>
Subject: Re: 4GB Physical. Less than 3GB in Linux.
Date: Mon, 16 Apr 2007 08:33:26 -0600	[thread overview]
Message-ID: <46238936.3060501@shaw.ca> (raw)
In-Reply-To: <fa.wZS4ieAkOMvNOj61QiUn9aS+YeM@ifi.uio.no>

Jeff Chua wrote:
> I've noticed that with 4GB physical ram, I'm only see 3098000 MB on
> the Dell 745, and 3107056MB on the IBM X60s.
> 
> I've tested with CONFIG_HIGHMEM4G=y, CONFIG_HIGHMEM64G=y,
> CONFIG_X86_PAE=y, but nothing makes any difference.

Chipset limitation. It uses up most of the MMIO region above 3GB 
preventing RAM from being mapped there, and doesn't support remapping 
the covered RAM to above 4GB. Nothing the kernel can do about it.

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


       reply	other threads:[~2007-04-16 14:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <fa.wZS4ieAkOMvNOj61QiUn9aS+YeM@ifi.uio.no>
2007-04-16 14:33 ` Robert Hancock [this message]
2007-04-16 14:52   ` 4GB Physical. Less than 3GB in Linux Jeff Chua
2007-04-16 19:56     ` Stefan Richter
2007-04-17 18:26     ` Jasper Spaans
2007-04-18  0:28       ` Jeff Chua
2007-04-16  7:28 Jeff Chua
2007-04-16 13:12 ` Fortier,Vincent [Montreal]
2007-04-16 14:17 ` Stefan Richter
2007-04-16 14:47   ` Jeff Chua
2007-04-16 18:25     ` Stefan Richter

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=46238936.3060501@shaw.ca \
    --to=hancockr@shaw.ca \
    --cc=jeff.chua.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.