linux-kernel - Re: 4GB Physical. Less than 3GB in Linux.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b6a2187b0704160752u1c837f33p652c0d431b66459@mail.gmail.com>
Date:	Mon, 16 Apr 2007 22:52:43 +0800
From:	"Jeff Chua" <jeff.chua.linux@...il.com>
To:	"Robert Hancock" <hancockr@...w.ca>
Cc:	lkml <linux-kernel@...r.kernel.org>
Subject: Re: 4GB Physical. Less than 3GB in Linux.

On 4/16/07, Robert Hancock <hancockr@...w.ca> wrote:
> 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.

Well, I guess I learned the hard way. So it's better not to buy 4GB
... it turns out to be the same as buying one with just 3GB RAM.

Thanks,
Jeff.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/